'3 '. 3" ""!.3;J';3-‘,.’"; 1:! 33"‘1315.C;€~34‘..r3" ': ' .. 3'-"‘J“..J;J3.II.‘3:'. “it" 3L33'33 "33'. l J 3‘ [Jr J J 1 .- “3.3 (. ‘ }.3'"-'*39}'|’3 ~...-J; 33.3333 -f| '1' '31 '3'3""."'3 I 333 '3 “33353363313333 333E" 3" .313} I|J3J';"§|33 J‘q 3.33M 3' '3 3"3'33 .3 ,J @4- .x 3.3331. 3333 333333' '3'333" 3333' 333333 JJJ 3'3... 3 . 33. 33J .J33JJIJ33'J3J333 333 333333.33 " J .333 3'33J33. 33.3333; 3‘ 33 .33 531' .3 J ' I.:J‘.--3 ; ' l3 3' ,'|-'|" ' f3 ' " J:' :33;" 3. 3.3333333" J 33 .3IJ ' 33 ' 3 |'33 '33 3..(,.; 3 J J . ' ' J 3333' .)'| '3 3'3" J33|3|3| «33‘3" 3' :"3y .' ,"313 J as“ '5 v:' .1. ' ‘ .. J' “3.33333" "3 J'3333'3J'"'313' 3.33.3 3333 3' ' 33 33J'3|. 33' 333 '33333333""33'333'3"3333'3‘J3¥3'33'33'333 3’ 33".. ' 3;." '| 3"“1’: ||.‘3|3J_3J3J3J|'3||| 3 ‘|:|3|"J|||| 3333 J 3 “333' 33333." ||| |J|| | 3||3|3|3|3J3J| 3 3 3 3" "335333 "3.3 " 33' J'J . .3333 3.1: JfoJmfixJ 5"}...‘333 $5.31 '3 4‘ a - n‘ - — affix-J'- .- .'.. ‘ - -‘ - J3. K-.. — - . .., . a o ‘ ' .. _, ‘ _ .1.“ u- -- ' ' " , ‘-.‘.‘ > . v ‘ - o _ _ V — - ' ~ A .-- . - "3' 31' 3'33 333' 33.33 g‘lx£"if'3‘3"333 '33" I '3‘: . I -' a .5. . J :4 3' §:..-‘,' 3- z I; w: ‘ V l.‘ 'o v' ' 'I.‘A.‘-, o‘ ‘ 3 ‘ I .33 a. 'f f < "~: -a‘.1-‘.. . n' ‘ 1.‘ ‘-.: 1'. v . ~.' .-. . ‘ . g. .3 . «v . 3... . -. - .,, 4.3 ~-.::: :7, ...- ; -‘- . J .‘.'3 . I 'vfu:,vu'o . J . 3" J . J '- v . 'U' -..|- 3'33. . n .7— '3 J3 3‘313 £5333“! 11113 3": 13.3333 '36 3"" 13'3' .333333J1k3l5. $333571? 3 ' :‘ ' I 3‘23”? . |.A. l '3‘! ”'3." mad! " - _;" Wm..- “W f‘“* “1%” 3|'.|.. 33' .3 .‘ "3|3333 J "1;".3‘. 3.3:? 33.33'3'3' '5' 1 || .. '33 '3 ‘33. '3. J ‘-" '3' ' ‘ 3.3 ' ' . 3. ‘-' "- '- 'J-H “3 '3' ' "". " 'J'" "‘I““3I 3‘" 3 3' €33.33 J~.1"J"3 ...;3':c333; 553.11. J. . .-5' . 3 |le .- "33 J'|3|J.J| 3‘ '|'3J|JJ‘ | J.' J|J ' 3 3.3.333 :3ng '31. 33' "3'3: v.3. .'. |.. |-I '. J‘“ 3'" '""3 "I '3I‘ '33' 3 333 '3 '33|J:J.3 3" 3 'r". .35 3' J33 .‘c‘g'. .33'?"'?-333'>3‘=g.. _ 'M. '3" "" ' 1' 3 3 |"3 3 33333 '3333 JJ3J3J|'33J '33'3333 3.3333333 3." ..r 33%;. 0 { I33' 3" 33" 3 (I |33'| r IIIIII i’;"3' JJ 3j |JJJ|JJ.'J .3 .JJJ I3". 3J|| 3J1J3|'|' 3.|333333 3'H.3 7- J'-|J' . 3.3.." 333. I. 33'. 3'3 '. 33'; ‘3"_' .I‘ 7"‘11'J‘3'J3'3'3 3.3.3 3 3.3.." II 3 3 3333 3 3 J33" "‘r ' ' ‘ .-"‘3"'3 '3 3 ‘3J3'J 3‘ J|.'.JI3|. ."'..;..‘.' .‘J 3 31.3333333' "33 . 'JJJ‘JJJ 3 '33333JJ'3JJ'33JJJ3JEJJ3'JV-"i'331'1 J '333J33'fl-fl'h.’ 'J- J. -_ ;_~_,_; . 3333‘ 133.333353”'1..." .' 33.5. "'..3JJ"'| 3.3 ||JJJJ IJJJ... 3J333J..33J ..J..' J.J '3‘... '3!" "'3' "J .33: 233 :31“? *°':.J"=‘3T'?".J".:LJ 33331.3. ’I‘I.‘ I: :I‘I'.' '3. r J' "'3... " J. J. .J‘ 3 J. .!:J ‘ " .3 -:..J.:.~'-. '."-'J'~‘< .“.‘ 433w». ||I33J'33v|'|‘||3||'IJ'33|3J3'|3|||3|||333lJ '3333'L' |33Jl 3|J |-3:|.'3'3 33.33" l||33r| ##JF'" 9’& "3331' |..||JIJ 3:23. I ' . ' J, 33' "WW" '3' 33333 v 131'- ‘ .‘.;1 .J 3 J 3 "I'I:.'33"J ‘ ' 3 '33 3-33.. . .33," .I J. J |, JJ 3.3 _... '3J'J'1. 3' ..' “ ‘ , ...'..‘....".I'3 3. "";.L¢L' 33'333133333‘33 THESlS f x 5‘ ‘ o 3‘ 4"“! 2‘ K J i r‘ t 3. c ' ‘ t . fl . _, ’1 )1 v " 'fi ‘~ m uw'ufi I} , ('1‘! ‘ This is to certify that the thesis entitled Hastening Drying Rate of Cut Forage by Chemical Treatment presented by Timothy R. Johnson has been accepted towards fulfillment of the requirements for M.S. degreein Animal Science ‘-- 1- MJQ/ Major cfr-..o Date 0-7639 MSU RETURNING MATERIALS: Place in 500E drop to LIBRARJES remove this checkout from your record. FINES will be charged if book is returned after the date stamped below. HASTENING DRYING RATE OF CUT FORAGE BY CHEMICAL TREATMENT By ‘3‘ Timothy R. Johnson " A THESTS * : . . Submitted to Michi an State university in partial ful illment of the requirement9~ ‘ * *3“” for the degree of ' P ,i ’,- pom": :; . I I I 4' MASTER or SCIENCE ‘ -- ‘0'}3'. ,. J- - 7"‘13306‘: r.' .. an. . A i e‘ffiec 1". ‘ "; ' '- , ' _I, ‘1, _ , 'Depertment of Animal Science _ iqud hypli." .- - 1x- . ‘ “' -. 1982 ,5 'ifipdw’f"; JV: A S} - ,9? '40 ‘Ct‘ ' ‘ , ‘ ' L R" F‘ J I: ;.“-I. . "' ‘33-‘61.“ C“ it J LIV eA‘ ‘ plia' 1'31 -s 'Oa~‘l‘\ - t A" - 4 tr . _' “ ‘*§ fuln:t , .. rte a": , t . #:12' m“ A:-:- t 2. . y {3 a. . -fi . l: , . , 7‘ fl - ‘ v: ,8. .. . .~;, '. , - . . 31.»: - ‘-‘ .. ,. ‘f24' . ”:4" 3’3} fl re: ".‘FfV , I' s .1"- '. . v‘. N. , y’ 74/}; 6// ABSTRACT HASTENING DRYING RATE OF CUT FORAGE BY CHEMICAL TREATMENT 33’ Timothy R. Johnson Solutions containing emulsified lipid mixtures and/or alkali salts were sprayed on cut forage in laboratory and field trials to increase rate of drying, thus reducing length of time cut forage would be at risk to adverse weather. Alkali metal carbonates increased mean DM content and drying rate of cut alfalfa (Alf) Li < Na < Rb < K < Cs. Mag- nitude of increase in mean DM after treatment with solutions containing K salts was greatest for solutions of Ph 13. Both K2C03 and methyl esters (ME) of long chain fatty acids hastened drying of Alf. Combinations of these two com- ponents increased drying rates above use of either component alone. The minimum effective application of ME in K2003 solutions was 0.5 gr ME/kg fresh forage weight. The most effective application was 2 to 3 grams ME/kg. Effectiveness of applied ME, K2C03 mixtures increased with increases in liquid application rates. Methyl ester, K2003 solutions hasten- ed drying of red clover and birdsfoot trefoil but not of brome or orchard grass. Spray treatment reduced respiration loss dur- ing field drying and interval from cutting to baling Alf at a DM "safe" for storage. Analytical values of sprayed and un- sprayed forage at baling and during storage were similar. ACKNOWLEDGEMENTS I would like to express my deep appreciation to Dr. J. W. Thomas, my major Professor, for his help and guidance both in my academic and research programs. Drs. Brook and Erickson were also very helpful suggesting new ideas and of- fering encouragement. I would also like to thank Larry Chapin and Drs. Gill and Anderson for their help with computer prob- lems and statistical design and analysis. Many thanks are also due Michelle Wieghart, Dick Lederhuhr, Ken Ahrens, Lisa Shakerin, Roberta McCall, Barry Jessie and my parents Roberta and Pricillia Johnson without whose help and guidance comple- tion of this project would have been impossible. ii TABLE OF CONTENTS Page ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . ii LIST OF TABLES . . . . . . . . . . . . . . . . . . . . vi LIST OF FIGURES . . . . . . . . . . . . . . . . . . . viii INTRODUCTION . . . . . . . . . . . . . . . . . . . . . 1 LITERATURE REVIEW . . . . . . . . . . . . . . . . . . 3 Factors Affecting Water Loss from Cut Forage . . . 3 Plant Mechanisms for Maintaining Moisture Equi- librium . . . . . . . . . . . . 3 Physiological Restraints to Water Loss in Cut Forage . . . . . . . . . . . . . . . . . . . . . 10 Environmental Constraints to Forage Drying . . . 14 Effect of Swath Micro Climate on Forage Drying . 15 Methods of Increasing the Drying Rate and Reducing Field Exposure Time of Conserved Forage . . 18 Mechanical Treatments for Decreasing Drying Time 19 Reducing Tissue Resistance . . . . . . . . . l9 Treatments to Decrease Swath Resistance to Drying . . . . . . . . . . . . . . . . . . . 22 Chemical and Thermal Treatments to Increase For- age Drying Rates . . . . . . . . . . . . . . . . 25 Inhibition of Stomatal Closure . . . . . . . 26 Destruction of Cuticular and Cellular Bar— riers to Water Loss . . . . . . . . . . . . . 27 Increasing Transpiration by Reversible A1- teration of Cuticle Surface Waxes . . . . . . 31 iii OBJECTIVES MATERIALS AND METHODS Laboratory Procedures Field Procedures Application of Chemicals to Increase Drying of Cut Forage Under Laboratory and Field Conditions . Hastening Forage Drying with Carbonates and Other Salts of the Alkali Metal Group Influence of Methyl Ester Source and Composition Emulsifiers and Surfactants Importance in Solu- tion Formulation and Forage Drying . . . . . Combined Effects of Potassium Carbonate and Methyl Esters . . . . . . . . . . . . . Optimum Amounts of Methyl Ester Addition . Influence of Changing Liquid Application Rate and Spray Pump Pressure on Forage Drying . Chemical Treatment of Different Forage Species and Plants in Different Physiological States Influence of Chemical Treatment on Length of Field Drying and Losses of Dry Matter and Nu- trients During Harvest and Storage . . . Laboratory Analysis Experimental Design and Statistical Analysis RESULTS AND DISCUSSION . Drying of Alfalfa Treated with Carbonates and Other Salts of the Alkali Metal Group . . . . . . . . Influence of Methyl Ester Source and Composition The Effectiveness of Various Emulsifiers and Sur- factants in Maintaining Lipid Water Emulsions and Speeding Drying . . . . . . . . . . . . . . . iv Page 37 39 39 41 45 45 46 47 47 47 48 48 49 52 52 53 53 66 70 Page Additive Effects of Methyl Esters and Potassium Carbonate . . . . . . . . . . 73 Optimum Amounts of Methyl Ester Addition . . . . 87 I Maximizing Coverage by Changes in Liquid Applica- tion Rate and Spray Pump Pressure . . 93 Chemical Treatment of Different Forage Species and Methods of Expressing and Evaluating Treat— ment Effects . . . . . . . . . 100 Drying of Alfalfa in Swaths or Windrows Under Variable Field Weather Conditions . . . . . 119 Apparent Respiration Losses During Field Drying . 123 Dry Matter Losses from Mowing and Raking as a Function of Chemical Treatment and Method of Estimation . . . . . . . . . . . . . . . . . . . 128 Changes in Amount of Dry Matter, Bale Tempera- tures, and Analytical Values of Baled Hay During Storage as a Function of Dry Matter Content and Chemical Treatment . . . . . . . . . . . . . . . 130 SUMMARY . . . . . . . . . . . . . . . . . . . . . . 142 BIBLIOGRAPHY . . . . . . . . . . . . . . . . . . . . 147 TABLE 10 11 LIST OF TABLES Methods of Expressing Ratios of Moisture to Dry Matter During Drying of a Forage Laboratory Experiments Testing Drying Parameters of Alfalfa Treated With Carbonates and Other Salts of the Alkali Metals . . Field Trials Testing Drying Parameters of Al- falfa Treated with Carbonates and Other Salts of the Alkali Metals . . Drying Rates During Given Periods Post- -Cutting for Three Laboratory Trials Ionic Radii and First Ionization Energies of the Alkali Metals . . . . . . . . . . . . Composition of Methyl Esters, Other Lipids and Emulsifiers Used in Spray Solutions Description of Drying Parameters for Laboratory Trials Testing Different Methyl Esters and Lipid Emulsions . . Emulsifiers and Surfactants Effectiveness in Hastening Drying of Alfalfa Treated with Potas- sium Carbonate and Methyl Ester Emulsions Measures of Drying When Alfalfa Was Treated With Methyl Esters or Potassium Carbonate Used Along or in Combination . . . . . . Drying Rates for the First and Second Days Fol— lowing Treatment with Potassium Carbonate or a Combination of Methyl Esters and Potassium Car- bonate . . . . . . . . . . . . . . . Mean Drying Rates and Dry Matter Content During First and Second Days After Treatment of A1- falfa With Potassium Carbonate, or a Combina- tion of Methyl Esters and Potassium Carbonate . vi PAGE 12 55 59 62 63 67 68 71 74 83 86 ‘_.—._ _. TABLE 12 13 14 15 16 17 18 19 20 21 22 23 24 PAGE Measurements of Drying After Treatment of A1- falfa With Increasing Amounts of Methyl Esters in Potassium Carbonate Solutions . . . . 88 Drying of Alfalfa as Influenced by Changes in Amounts of Applied Liquid or Spray Pump Pres- sure . . . . . . . . 97 Description of Drying Parameters for Control and Chemically Treated Red Clover (RC), Alfalfa (Alf) and Birdsfoot Trefoil (Bft) . . . . . . . 101 Measurements of Drying Responses of Bromegrass (BG), Orchard Grass (0G) and Alfalfa (Alf) at Different Maturities or Grown Under Different Conditions to Chemical Treatment . . . . . . . 113 Drying Rates of Brome Grass, Orchard Grass and Alfalfa at Given Water Contents Between 5.0 to 0.5 . . . . 116 Characteristics of Alfalfa Grown Under Green House and Field Conditions . . . . . . . . . . 118 Measures of Drying for Chemically Sprayed and Unsprayed Alfalfa that Was Left in a Swath or Windrow After Mowing . . . . 120 Drying Rates of Alfalfa Before and After Dew and Rain in Two Field Trials . . . . 122 Apparent Respiration Losses During Drying in Eight Field Trials . . . . 124 Dry Matter Losses from Mowing and Raking as Estimated by Two Methods . . . . . . . . . . . 129 Interval from Cutting to Baling, Dry Matter Content at Baling, Bale Temperatures and Dry Matter Losses IDuring Storage for Five Field Trials . . . . . . . . . . 131 Analytical Values for Control and Sprayed Alfalfa at Baling and After Storage . . . . . 134 Analytical Values for Unsprayed and Sprayed Alfalfa as Baled at 77 to 82Z Dry Matter and After Storage . . . . 137 FIGURE 1 2 LIST OF FIGURES Generalized plant cuticle structure . Drying rates of alfalfa treated with potassium carbonate, emulsified methyl esters or a combi- nation of these compounds over 47 hours of dry- ing (Trial L14). . . . . . . Drying rates between water contents of 6.0 and 0. 5 for alfalfa treated with potassium carbon- ate, emulsified methyl esters or a combination of these compounds (Trial L14). . . . . Dry matter content of three legume species dur- ing 23 hours of drying with or without chemical treatment at cutting (Trial L17). . . . Drying rates between water contents 3.5 and 0.5 for three legume species with or without chemi- cal treatment (Trial L17). . Percentage of initial water remaining in three legume species with or without chemical treat- ment over 23 hours of drying (Trial L17). viii PAGE 78 80 103 106 110 INTRODUCTION Forages are important in the United States livestock industry, supplying more than half the feed units consumed by farm animals. Increases in world population and demand for cereal grains as human food sources and to produce alcohol fuels may increase the importance of both yield and quality of forages as they are substituted for feed grains in livestock rations. Several factors limiting the utilization of roughage based rations have been identified. Intake can be limited by gut fill when forages of low quality are fed, while fermenta- tion by-products have been shown to limit consumption of some hay crop silages. Digestability of forages is generally lower than for cereal grains due to a greater cell wall fraction, and to lignin and silica complexes with this fraction. Proper conservation of forages as dry hay or silage at the optimum stage of maturity can maintain ration quality and animal performance throughout the year. A considerable amount of research effort has been di- rected towards improving cultural practices and breeding for- ages with high yield potential. Attempts to increase utiliza- tion of crop residue and low quality forages through mechanical and chemical treatments have also received much attention. On the other hand, comparatively little emphasis has been directed toward the problem of large dry matter and nutrient losses dur— ing harvest and storage of high quality forage crops. Length of time the crop is exposed in the field is related to reductions in digestability and intake potential. We therefore undertook the present investigations examining the feasibility of applying chemicals at cutting to alfalfa and other forages to speed drying and decrease length of field exposure. LITERATURE REVIEW Factors Affecting4Water Loss From Cut Foragg Production of high quality wilted silages and hays re- quires that a considerable amount of water originally present in the fresh forage be removed. To evaluate management pro- grams for producing conserved forages of high intake poten- tial and nutritive value, proper consideration should be given to speed of moisture removal and losses of dry matter and nu- trients in the field and in storage. Factors that control water loss and homeostasis in the growing plant may be related to speed of water loss after cut— ting. Physiological limits to water removal are set by gen- etically controlled factors and by the environment. This poten— tial for water loss is further modified by environmental condi- tions during field drying and by the harvesting methods employed. Plant Mechanisms for Maintaining Moisture Equilibrium In the intact plant, moisture equilibrium must be main- tained under wide variations of temperature, humidity, air movement and water availability. Several mechanisms which govern gain or loss of water by the aerial portion of plants in extreme conditions have been identified and will be briefly discussed. The primary pathway of water and gaseous transpiration in the intact plant is through the stomata. About 80 to 902 of water lost in growing plants has been estimated to follow this route (Sullivan, 1973). Stomatal aperture is control- led by the turgor of the two guard cells located on each side of the stomatal cavity. The active transport of Potassium (K+) ions into the guard cells causes an increase in turgor and an opening of the stomata (Fisher, 1968). Potassium de- ficiency in tea (Camellia Sinensis) has been shown to increase stomatal resistance to water loss by limiting K+ available for transport into the guard cells. Sodium ions (Na+) can partially substitute for K+ but Na+ additions cannot com- pletely overcome the effects of potassium deficiency (Nagarajh, 1979). Stomatal opening and closure follow a di- urnal rhythm in alfalfa primarily affected by light intensity and concentration of intercellular C02. Stomata began to open at dawn and a maximum percentage of open stomata is reached at mid-day (Jones and Palmer, 1932). Stomatal frequencies in alfalfa leaves and stems of 292-700/sq mm and 300/sq mm respectively, have been observed (Hayward, 1938). These are randomly spaced with about equal numbers on both the abaxial and adaxial leaf surfaces. Grass leaf blades on the other hand, have only 71-121 stomata/sq mm. These are primarily located on the adaxial surface in single or double rows. The stomata lie between bands of motor or bulliform cells which are not cutinized and thus rapidly lose water in moisture stress conditions. The de- crease in turgor of these cells causes leaf rolling (Hayward, 1938). A subsequent decrease in transpiration has been shown in water stressed rice (O'Toole and Cruz, 1979). Stomata quickly close during conditions of moisture stress. In both clover and tall fescue closure is complete when 302 of the water normally contained in the plants has been lost (Johns, 1972). Once the stomata are closed the primary route for water loss in either grasses or legumes is through the plant cuti- cle. The cuticle covers most of the exposed surface of plants, excluding the guard and bulliform cells. The cuticle protects the epidermal cells from water loss, abrasion, and from en- trance of pathogens or water in wet conditions. The cuticle is composed of four layers (Figure 1): 1) An epicutical wax layer made up of wax platelets or rods; 2) Cutin; 3) A cutin- ized layer embedded with wax; and 4) A pectin layer (Eglinton and Hamilton, 1967). Epicuticular waxes are only secreted in actively growing leaves (Hall and Jones, 1961). If this wax is removed by weathering or artificially by brushing or wiping leaves (Hall and Jones, 1961; Schieferstein and Loomis, 1956) or apples (Hall, 1966) transpiration is increased. When leaves are still actively growing any wax removed stim- ulates additional wax secretion. While this regeneration of surface waxes will not occur in mature leaves, waxes may still be produced and deposited as wax inclusions as the aEpicuticular wax_layer. b Cutin. cCutinized tissue with wax inclusions. dPectin eSubcuticular cellular layers. Figure 1. Generalized Plant Cuticle Structure. -fia'- cuticle thickens (Sitte and Rennier, 1963). Halloway (1969) has stated that this wax imbedded in the cuticle is primarily responsible for cuticular resistance to water loss, while sur- face waxes primarily act to repell surface water allowing ef- ficient transpiration. Temperature and photoperiod have been shown to effect the rate of wax secretion and wax chemical composition in tobacco (Wilkinson and Kasperbauer, 1979). Total epicuticu- lar wax production was increased with long photoperiods at 18° C but there was no significant differences in wax produc- tion between photoperiods at 28° C. Long photoperiods and cold temperatures also stimulated wax production in clover which may be related to frost hardiness (Hall and Jones, 1961). Periods of water stress, long photoperiods and low relative humidity caused increases in wax production in populus clones (Pallard and Kozlowski, 1980). These authors also noted that ledges of wax form and cause occlusion of the stomata in young water stressed leaves, suggesting that cuticular waxes can affect stomatal transpiration. Variations in wax structure between "greenhouse" and field grown velvet mesquite (Prosopis Velu- tina woot) have been noted (Bleckmann et a1., 1980). Cuticu- lar thickness was 10 times greater for field grown plants. The size of the crystallized wax platelets and rods were also much greater in field samples. Cuticular wax characteristics have been studied by many workers interested in improving herbicide wetting and penetration. Holloway (1969) states that wax texture and the exposed chemi- cal groups of the waxes govern wetting of leaves. Epicuticu- lar wax dissolved in various organic solvents and then recrystal- lized regains the original ultrastructure (Jeffree et a1., 1975). This shows that chemical composition can determine surface wax structure. Cuticular waxes are primarily composed of mixtures of aliphatic even carbon alkanes, secondary alcohols, odd numbered carbon chain esters, and primary alcohols (Holloway, 1969). These chains are oriented so the terminal methyl groups are exposed on the surface. The more closely these methyl groups are packed the less wettable the wax is. Pure alkanes pack the closest because they lack side groups. The presence of esters, ketones and primary alcohols in the wax mixture in— crease wetting substantially (Holloway, 1969). Composition of surface waxes can change during the growth process. Increased photoperiod has been shown to in- crease the relative amounts of even carbon chain fatty acids and alcohols in tobacco (Wilkinson and Kasperbauer, 1980). Low temperatures along with long photoperiods increased the relative amounts of alkanes and fatty alcohols present in epicuticular waxes, while little change in composition due to leaf maturity was reported (Wilkinson and Kasperbauer, 1980). On the other hand, an increase in neutral lipids and a decrease in polar lipids has been reported in maturing grape berries (Gallander and Peng, 1980). Aldehydes, hydrocarbons and alcohols isolated from grape berry cuticules have been shown to be the components most important in reducing transpiration. Fatty acids, C24-28’ are intermediate in effectiveness while oleanolic acid, the principal component of the hard wax fraction, does not significantly reduce water transpiration (Grncarevic and Radler, 1971). The principal constituents of alfalfa cuticular waxes are the long chain primary alcohols n-triacontanol, n- octaconsanol and esters of these two alcohols. Hydrocarbons of C to C are also present (Blair et a1., 1953). Rye- 29 31 grass cuticular waxes contain esters of long chain C27 to C 33 hydrocarbons and B-diketones (Eglington et a1., 1962). Research directly comparing drying rates of cut for— ages grown under different environmental conditions has not been reported in the literature. Low humidity, water stress, long photoperiods and cold temperatures cause thickening of plant surface waxes (Hall and Jones, 1961; Pallard and Kozlowski, 1980; Bleckmann et a1., 1980). These environmental conditions would be expected to decrease subsequent rates of water removal after cutting. On the other hand, the weathering of forages as maturity increases removes surface waxes and would be expected to increase the rate of drying. Slow drying of cut forages in early spring and late fall may be related to a thickened wax layer developed during the growing period. ~———- 10 The cutin matrix, made up of cutin, cutinized tissues imbedded with wax and pectin (Figure 1) may also limit dif- fusion of water to the plant surface. Changes in the perme- ability of isolated cuticles treated with a solvent to re- move surface waxes is dependent on pH and presence or absence of monovalent cations in the media (Schonherr, 1976). Per- meability increases five fold as pH is increased from 3 to 11 in the presence of monovalent cations. The effectiveness . . . . . + of various cations in decreas1ng order 13: Rb. > Rf > Na”.r > Lil. The author suggests that permeability is increased to a greater extent by the largest cations due to a lower charge density and preferential association of these ions with non-esterified carboxyl groups in the cutin matrix. Between pH 3 and 9 two different carboxyl groups dissociate at the base of pores within the cuticle. The second group dissociating only in the presence of alkali metal ions. Above pH 9 phenolic hy- droxyl groups begin to dissociate causing a further opening of_these pores, allowing even greater amounts of water to pass through the cuticle matrix (Schonherr, 1976). ‘Physiological Restraints to Water Loss in Cut Forage Evaporation of water from wet blotting paper is more than 40 times as fast as from freshly cut ryegrass when they are both subjected to 7% relative humidity (RH) and a wind speed of 80 cm/sec (Leshem et a1., 1972). Internal resistance 11 to evaporation increases progressively as the water content (WC) of cut forage declines during drying (Klinner and Shepperson, 1975). The considerable tissue resistance and nonlinear de- crease in rate of water removal has led to a search for proper mathematical expressions for moisture content and for rate of water removal in cut forage. The most commonly used expressions for moisture content are Z dry matter (DM)1 and its recipro— cal Z moisture,2 water content3 and Z of initial water re- maining.4 The latter two have denominators which are theo- retically constant during the whole drying process. This allows these two expressions to be used in equations which determine rates of water removal over time. WC and Z of initial water remaining also place emphasis on the large amounts of water which must be removed before forages can be safely stored. An example of the expression of moisture content by each method over a typical range of moisture con- tents for alfalfa cut for hay is presented in Table l. l _ units DM DMZ ' units total sample wt x 100' 2 . _ units water M01sture Z _ units total sample wt x 100' units water 3 3 WC units dry matter' l’gnits water at time t x 100 units water initially present ' 12 Table 1. Methods Expressing Ratios of Moisture to Dry Matter During Drying of a Forage. Dry Matter Moisture Water Content Z of Initial Water Hours Z Z Remaining 0 20 80 4.0 100.0 4 30 70 2.3 57.5 10 50 50 1.0 25.0 26 70 30 0.4 10.7 30 75 25 0.3 8.3 38 80 20 0.25 6.3 Increases in tissue resistance and the subsequent de- crease in rate of water loss during drying is due to a combi- nation of factors and is best understood by following the physiological changes in the plant after cutting and during drying. Immediately after cutting there is a temporary in- crease in respiration due to opening of the stomata (Sullivan, 1973). The duration of this stomatal phase has been estimated to last from 30 minutes (Clark and McDonald, 1977) to 2 hours (Jones and Palmer, 1932). Shepard (1964) demonstrated that the leaf stomata from white clover close before those on the petiole. This suggests that there may be a critical mois- ture content at which stomata close, leaf stomata closing before those on the stem because leaves dry faster. Hall and Jones (1961) on the other hand noted a dramatic decrease in the rate of water loss, from white clover at 2 to 3 hours after cutting with no second deflection of the curve of DM _~—.. 13 vs time after cutting. They attribute this to complete stomatal closure by that time. Green (1975) reported that, during the first 2 to 3 hours of drying, tissue resistance increases from 2 to 5 sec/cm in the standing crop to 20-100 sec/cm as the stomata close. The two major routes for water loss after the stomata close are diffusion through the cuticule and direct evapora- tion from surfaces exposed during cutting and conditioning. Water movement in cut herbage is both radial and longitudi- nal. Bagnell et a1. (1970) found a 30% decrease in water loss from two inch sections of alfalfa stems when radial move- ment of water was limited by putting the stems in tight fit- ting glass tubes. In whole stems of alfalfa crimping has been shown to increase longitudinal movement of water (Pen- dersen and Buchele, 1960). These data suggest that there is strong resistance to radial diffusion and that water will move along the path of least resistance. Transfer of stem water to the petioles and leaves where resistance to diffusion is lower has been demonstrated in both grasses (Jones, 1973), and legumes (Byers and Routely, 1965; Shepard, 1964). Harris and Tullberg (1980) have extensively reviewed this subject and estimate that up to 352 of the water contained in the stems at cutting exits the plant by this route which remains active until the stems reach 402 DM. As plants mature the stem:1eaf ratio and tissue resistance to drying both increase (Green and Jagger, 1977). This finding is probably related 14 to the larger surface to mass ratio of leaves, but may also reflect a very active stem to leaf transfer in leafy crops. The importance of the plant cuticule in limiting dif- fusion of water vapor in the cut plant has been demonstrated by Bagnell et a1. (1970). Scraping alfalfa stems to remove the cuticle and epidermal cell layer greatly increased drying rates while further scraping down to the vascular layer gave little further response. Removal of the epicuticular waxes by brushing leaves (Hall and Jones, 1961) or dipping leaves in petroleum ether (Harris et a1., 1979) has also been shown to greatly increase drying rates. These data support the idea that these waxes contribute significantly to cuticular resist- ance to drying. Environmental Constraints to Forage Drying For drying of forage to proceed a positive gradient of vapor pressure between the plant and atmosphere must exist. There must also be sufficient energy to evaporate this dif- fused moisture from the plant surface. Forage water content and temperature control the vapor pressure within the plant. As the plant dries internal vapor pressure decreases, thus increasing the importance of external vapor pressure in limit— ing further drying. Drying ceases when equilibrium humidity, defined as the relative humidity at which vapor pressure within the plant is equal to vapor pressure in the surrounding air, is reached. Equilibrium humidity values decrease in a curvi- linear fashion, decreasing slowly to a WC of 0.5 and then 15 falling sharply below this point (Green and Jagger, 1977). Because drying can only proceed if relative humidity is less than equilibrium humidity a low relative humidity becomes an increasingly important factor as the plant dries. Leshem et a1. (1972) studying single grass stem and leaf sections found a direct relationship between the speed of moisture loss and vapor pressure deficit (VPD), where VPD is defined by the equation: VPD = [l - (RH/100)] x (saturation vapor pressure) This offers the possibility of predicting drying from routine weather data by calculating a value that reflects drying po- tential. In the field VPD generally follows a diurnal pat- tern being low in the early morning and increasing to a peak at noon on a favorable summer drying day. This is maintained for several hours and then declines steeply in the late after- noon as solar radiation decreases (Clark and McDonald, 1977). Effects of Swath Micro Climgte on Forage Drying For the first 6 to 10 hours after cutting the top layer of the swath dries at a rate 5 to 10 times faster than the lower layers. External and internal swath environmental para- meters were compared during this period by Green et a1. (1976) With an ambient relative humidity of 50%, air speed of 2 to 3 meters/sec and direct solar radiation at the surface of the swath, they found that RH increased to 802 and wind speed decreased to .l to .2 m/sec at 2 cm depth in the swath. “"7 16 Solar radiation was calculated to be 502 of what struck the surface at 2 cm and only 10% at a depth of 10 cm. The audxus con- cluded that poor ventilation led to high humidity within the swath and a lack of sufficient energy to evaporate water from the surface of the forage added to the unfavorable conditions for drying. Water loss from wet blotting paper is increased with high wind speeds but no significant increase in evaporation from single cocksfoot leaves was noted (Leshem et a1., 1972). On the other hand, Shepard (1965) found a 492 increase,for the first 3 hours, in the drying of single clover stems with an air speed of .4 m/sec compared to still air. He found that the importance of wind speed decreases during the drying per- iod until at a WC of 1.0 (50% DM) wind speed had no signifi- cant effect. In the field optimum wind speeds for bulked material over the total drying period have been estimated to be 2.2 m/sec (Klinner and Shepperson, 1975). Soil moisture is frequently high especially during June or after irrigation in Michigan. Laboratory studies have compared the drying of crimped alfalfa on air dry soil, soil of 152 moisture and a soil of 152 moisture covered by a plas- tic vapor barrier. Alfalfa dry matter contents after 22 hours of drying were 84.32, 59.72, and 85.92 respectively (Penderson and Buchele, 1960). Increasing stubble length from 50 mm to 130 mm has also been shown to increase drying rates (Klinner 1976), possibly by keeping the swath from contracting the soil 17 and allowing more air movement around and under the swath. In the final stages of the forage drying process there is a sharp increase in tissue resistance which may often ex- ceed the importance of environmental constraints to forage drying. Increases in solute concentration and in the length of travel for vapor to reach an evaporative surface have been proposed as possible causes for the large increases in tissue resistance when herbage is between 60 and 80% DM. Green and Jagger (1977) demonstrated that increasing the rate of evapora- tion can increase tissue resistance. Shrinking of the plant tissue during dehydration and the development of a moisture gradient between stem surface tissues and internal tissue may be responsible for this finding. Equilibrium humidity is a function of surface moisture content and could limit water loss if a moisture gradient occurs between internal and ex- ternal tissues. This relationship has been altered by scraping, treat- ment with petroleum ether, or potassium carbonate (Harris, 1979). These treatments, all thought to work by removing sur- face waxes or changing wax ultrastructure, increased drying rates even in the final stages of drying from 65 to 802 DM. These data generated in the laboratory warrant further investi- gation and should stimulate interest in development of prac— tical systems to speed hay drying in the field by the use of chemical or mechanical treatments to reduce tissue resistance. 18 Methods of Increasing the Drying Rate and Reducing Field Exposure Time of Conserved Forages Losses of dry matter and nutrients have been related directly to field exposure time (Shepard et a1., 1954). Losses of dry matter under rainy unfavorable weather may approach 30 to 402 (Klinner, 1975; Shepard et a1., 1954). These high losses are primarily due to leaching, continued respiration, microbial fermentation and leaf shatter during subsequent harvesting. Hoglund (1964) reported that field DM loss is roughly propor- tional to DM content at harvest. Conservation methods which allow removal of the forage from the field at lower DM contents such as wilted silages or high moisture hay, to be artificially dried, reduce field losses. Storage losses which are inversely related to DM at harvest are generally larger when forage is har- vested at a relatively high moisture content. Field cured hay, barn finished hay and wilted silage had comparable total DM losses at first harvest of 17.32, 15.12 and 18.12 respectively, when drying conditions were favorable, while total DM loss for hay that experienced 1.68 cm rain was elevated to 33.82 (Shepard et a1., 1954). Because of these large potential losses several investi- gators have attempted to increase the drying rate of hay. Mechanical, thermal and chemical treatments have all shown some effectiveness and certain aspects of their action will be discussed. The practicality of any system which increases 19 drying rates will depend on the cost of materials, labor, and energy balanced against the potential saving of available nutrients. Mechanical Treatmgnts for DecreasingiDrying Ting Mechanical treatments that increase the drying rate of forages can be divided into two groups: 1) treatments pri- marily acting to reduce tissue resistance by crushing or splitting the stems and abrading the cuticle; and 2) treat- ments providing a more favorable microclimate for forage drying within the swath; the latter usually by disturbing the swath structure during the drying period. Reducing Tissue Resistance Mechanical conditioning can reduce cuticular resist- ance by: l) removing some of the cuticular waxes and 2) by splitting open plant tissues thus bypassing the cuticular bar- rier. Increases in drying due to traditional crushing treat- ments are generally less in grasses than in legumes (Boyd, 1959). Complete crushing of the pseudo stem with high roller tension is needed to increase drying rates of annual sorghum- sudan grass crosses (Barrington and Bruhn, 1970). Alfalfa on the other hand, will respond adequately to milder crimping or crushing which primarily acts to equalize the drying rates of the stem and leaves. 20 The magnitude of increases in legume drying rates is directly related to the severity of treatment, with flail chopping being more effective than crushing which is more effective than crimping (Boyd, 1959; Bruhn, 1959; Klinner, 1975). Increasing increments of laceration by flail chopping alfalfa has shown that there is an optimum severity of damage to the plant beyond which drying is decreased (Hall, 1964). The author attributes this to matting of the more finely chop- ped material in the swath. No advantage in drying was observed for delaying crush- ing while a second conditioning 0.5 hour after the initial cutting and crushing did significantly increase drying rates (Barrington and Bruhn, 1970). Increasing the severity of mechanical treatments is also associated with increased field DM losses. Total losses were 15 to 302 with flail conditioned hay compared to 9 to 112 for crimped hay under good drying conditions (Boyd, 1959; Barrington and Bruhn, 1970). Losses of DM and cell solubles after flail mowing can be particularly high if rain occurs (Klinner, 1975). In a review of early literature Shepherd et a1. (1954) stated leaching losses from rain could range from 5 to 142 of the original DM. Respiration losses after extended peri- ods of rain were higher for conditioned than non-conditioned forage as measured by CO2 evolution (Honing, 1980). The 21 author suggests that large losses of DM after rain, usually attributed to leaching may primarily be due to microbial ac- tion, reducing soluble carbohydrates by as much as 502. Respiration losses in the absence of rain have been reported to range from 4 to 182 of the initial DM present in legumes (Shepherd et a1., 1954, and Dale, 1980) and from 3 to 72 for grasses (Schukking and Overvest, 1980, and Honing, 1980). The magnitude of this loss is related to temperature and the time required to reach 60 to 652 DM (Dale, 1980), but is unrelated to severity of usual mechanical conditioning (Honing, 1980). Total mechanical losses from mowing, conditioning, rak- ing and packaging vary greatly with weather conditions and drying time (Shepherd et a1., 1954), the number and severity of machine operations (Barrington and Bruhn, 1970, and Coitti and Cavallero, 1980), and the DM content of the herbage at the time the operations are performed (Honing, 1980). Conditioning treatments primarily increase drying ratesl during the early stages of drying from 20 to 402 DM (Klinner, 1976). Drying rates during the final critical stages of field drying from 65 to 802 DM have been increased by "Maceration" of alfalfa. This process involves passing forage through dif- ferential speed, serrated rollers (Krutz and Holt, 1979). Increase in drying rate may in part be due to the increase in absorption of solar radiation in "macerated" alfalfa shown by Ajibola et a1. (1980). 22 Research in the United States has tended to involve severe mechanical treatments in an attempt to dry forage suffi- ciently for baling the same day that it was cut. European investigators on the other hand have been primarily concerned with developing methods which provide even cuticle abrasion without reducing stem strength. Scraping away epicuticular waxes was more effective than splitting alfalfa stems longi— tudinally (Bagnell et a1., 1970). This idea led to the develop- ment of several experimental and commercial mowers which com- bined either a reciprocating cutter bar or drum mower, with a rotary beater that hurled the forage against a shield, stem end first (Klinner, 1975). In addition to cuticle abrasion these machines also produced a high loose windrow structure. In- creased drying rate from use of these machines was comparable to standard crimping procedures but was smaller than from flail mowing. Field losses were also similar to those for crimping. No data were presented on losses after rain damage but the author suggested that losses would be smaller compared to treatments that tended to rupture plant cells. Treatments to Decrease Swath Rgsistance to Drying Environmental conditions, as previously indicated, are often the most limiting factors to forage water loss during early drying while tissue resistance is minimal. Drying slows as the lower layers of the swath develop a high relative hu- midity within the bulked forage. Drying rates of uncrimped and crimped alfalfa mowed and left in a swath as wide as the 23 machine cut dried at a faster rate than forage cut, crimped and windrowed in one pass (Fairbanks and Thierstein, 1966; Barrington and Bruhn, 1970). This indicates that the decreased surface area for interception of solar radiation and increased swath density associated with windrowing at cutting are more limiting than cuticular resistance during early stages of drying. Jones and Palmer (1932) found that raking immedi- ately after cutting decreased drying rates. They attributed this to premature stomatal closure in the dark interior of the windrow. Tedding of forage involves scattering the cut swath by use of a machine with rotary tines during the drying period. Tedding twice or more during drying is a routine practice in many parts of Europe but is not generally practiced in the United States. Tedding disturbs the microclimate within the swath and brings wetter material from the inner layers to the surface where conditions for drying are more optimum. Tedding immediately after mowing has increased drying rates, possibly due to increased cuticle abrasion, but tedding was most effective between a WC of 2.0 and 0.5 (33 to 672 DM) in grass swaths (Jones and Pickett, 1977). In Europe much of the tedded hay is grass. Dry matter losses due to leaf shatter would be expected to be much smaller for grass than legume hays at the low WC of 0.5. The type and adjustment of the tedding machine would be critical in 24 minimizing dry matter losses during this operation. Barring- ton and Bruhn (1970) utilized a rotary tedder as a condition- ing treatment for alfalfa soon after mowing. Increases in drying rates were smaller than for crushing while DM losses were larger, 102 for tedding and 72 for crushing. Swathed forages are generally bulked into a windrow for the final stages of drying with a side delivery, rotary or finger type raking device. Raking treatments expose damp pockets of forage at the base of the swath to conditions more favorable for drying and create a structure which allows more passage of air through the herbage. Raking at a DM of 40 to 502 produced the fastest drying to a BM suitable for storage aslmy (Jones and Palmer, 1932). Raking into a windrow at the end of the first day, if possible, was emphasized because during the night swaths picked up more moisture from dew than did hay in a windrow. Windrowed hay responded more slowly to weather changes than did hay in the swath (Fairbanks and Thierstein, 1966). Thus windrowed hay would be less effected than swathed hay during short periods of unfavorable weather but after ex- tended periods of rain or high humidity windrowed material would redry more slowly. Delaying raking until the forage averages above 50 to 602 DM is usually associated with excessive leaf loss. The susceptibility of alfalfa to leaf loss during mechanical treat- ments is greater when stem-leaf moisture differences are high (Raghavan and Bilanski, 1974). This would indicate that '- 25 treatments such as crushing or crimping at cutting which in- crease the drying rate of stems more than leaves have the potential to decrease leaf loss during raking. A high degree of management ability must be practiced to effectively maxi- mize drying potential by the use of mechanical conditioning, tedding, and raking operations while keeping dry matter losses at an acceptable level. Chemical and Thermal Treatments to Increase Forage Drying Rates Interest in chemical and thermal treatment of forage to hasten drying has been generated due to the large field losses and lack of sufficiently satisfactory improvements in forage drying and quality following mechanical conditioning. Results from trials using a combination of mechanical and chemical conditioning have also generally shown larger re- sponses than for either treatment alone. This suggests that modes of action may be different, and provides the challenge of finding a combination of chemical and mechanical treatments which maximize drying potential while minimizing nutrient losses and added costs. Chemical and thermal treatments of forage have followed two major approaches: 1) desiccation of the standing forage by treatment 24 to 48 hours before cutting and 2) applying treatment at, or soon after cutting. The first alternative 26 has several disadvantages. An extra field operation is re- quired, standing forage is trampled,and results may be vari- able if weather conditions are not favorable during desicca- tion. This also brings up the question of whether precutting treatments would have any advantage over a control cut at the same time that the treatment is applied. Most researchers in this area have recognized these limitations and investiga- tions are now generally directed toward developing treatments that are effective when applied at cutting. Work in both of these areas will be briefly discussed, emphasizing modes of action and practical field applications. Inhibition of Stoggtal Closure Fusicoccin, a wilt toxin produced by the fungus fussicoc- gnm amygdali 221., sprayed 3 hours precutting as a lO-SM solu- tion in 0.0012 ethyl alcohol decreased time for hay to reach 802 DM by one-half and reduced soluble carbohydrate losses due to respiration (Turner, 1970). In the field this same treat- ment applied by a field sprayer 3 hours before cutting decreased the time to reach 782 DM from 54 to 46 hours. Fusicoccin is thought to act by inhibiting stomatal closure, thus prolonging the initial drying period of minimal tissue resistance. Fusicoccin initially increased stomatal resistance to water loss but at 3 hours resistance declined to only 27.52 of con- trol (Turner and Antonio, 1969). Sodium azide has been shown to inhibit stomatal closure by preventing water efflux from the guard cells. This treatment a- 27 is most effective when the stomata are fully open (Stalfet, 1957). In laboratory studies dipping alfalfa in solutions of 5 x 10-3 M sodium azide in a sodium tartrate buffer at pH 4.5 caused an initial increase in drying rate (Tullberg and Angus, 1972). This increase was primarily due to an increase in leaf drying and resulted in a slower drying of the stems in the later stages of drying. Only a small reduction in time to reach a DM sufficient for storage was reported (Tullberg and Angus, 1972). Destrngtion of Cuticular and Cellular Barriers to Water Loss Heat or various herbicides known to change cuticle struc- ture or alter cell wall integrity have been used to increase the drying rate of forages. These treatments are generally more effective when applied 24 to 48 hr before cutting to al- low for wilting of standing forage. This may be due to a more complete disruption of cellular membranes in the turgid ac- tively growing plant. Steam treatment of cut perennial ryegrass at 100° C for 60 seconds decreased the time to reach 462 DM by half under laboratory conditions. When samples were exposed to the vapor from a 102 petroleum ether, water mixture a further de- crease to one-fourth the time required for controls to reach 462 DM was obtained (Harris et a1., 1974). Examination of steamed alfalfa stems with the scanning electron microscope has shown splitting of the epidermus and a disappearance of 28 the wax platelet structure with little change in internal cell structure (Byers and Routely, 1965). These authors compared mechanical crushing, steam treatment and a combination of these treatments in the laboratory and reported that while crushing was more effective in speeding drying than steaming, the combination of the two treatments was better than either treatment alone. They concluded that a combination of treat- ments which would both increase exposure of internal tissues and reduce cuticular resistance would optimize drying. A machine for field application of steam to standing hay crops has been built (Philipsen, 1969). Application of steam to a standing crop of alfalfa 24 hours before cutting using this machine was compared to a control cut at the same time the steam was applied. After tedding the hay twice daily, time to reach a DM suitable for storage as hay was the same for the two treatments (Wilkins and Tetlow, 1972). The field effectiveness of rapid treatment of alfalfa with a butane flame has been tested both 24 hours before cut- ting and immediately after cutting (Person and Sorensen, 1970). Flaming 24 hours before cutting caused a 172 drop in the water content of the standing crop. This treatment was compared to mechanical conditioning, flaming plus mechanical conditioning and an untreated control. Hours to reach 802 DM were 100 for flame; 95 for conditioning; 78 for flame plus conditioning; and 100 for control. Flaming alone had an initial advantage over conditioning until 502 DM was attained; it then dried 29 more slowly than conditioned or control material. The combi- nation of flaming and conditioning forage continued to have a significantly higher dry matter content. Herbicides have been used as an effective aid in the preharvest desiccation of alfalfa and clover for seed produc— tion. Several attempts have been made to increase forage dry- ing rate by applying contact herbicides at or before cutting for hay. Endothal, dinitro-ortho-secondary butylphenol (DNOSBP) and tributyl phosphate were applied at a rate of 1.1 1b/acre (1.5 kg/ha) in 46 to 130 liters water/ha at 0, 24 and 48 hours before cutting (Kennedy et a1., 1954). No significant effect for any of the treatments when applied at cutting was reported. The extent of precutting desiccation was directly related to the interval between treatment and cutting. The initial advan- tage for precutting treatments over control was primarily due to drying of the leaves. At 48 hours the DM 2 was 78 for both endothal and control treatments. Sheperd (1959) also reported that the effect of the herbicide ethylene dipyridilium was much greater on the leaves than on the stems of alfalfa. The mode of action of DNOSBP and ethylene dipyridilium is to penetrate cell membranes and destroy their selectivity to ion permeability. Disruption of the cell walls also al- lows free movement of water to the surface (Audus, 1964). The application of .252 tributyl phosphate doubled the drying rate and decreased soluble carbohydrate losses in cut ryegrass 30 (Harris, 1975). Tributyl phosphate sprayed on alfalfa before cutting in the field also increased drying rates but caused yellowing and excessive leaf losses during harvest (Kennedy, 1954). The use of contact herbicides for increasing drying rates of hay has two major limitations: 1) herbicides have only been shown to be consistently effective in precutting treat- ments and 2) chemical residue problems may preclude their use as desiccants on animal feed crops. In a laboratory trial formic acid sprayed at l, 3 or 52 of fresh plant weight produced a four-fold increase in drying rate (Thaine and Harris, 1973). Increasing application rate above 12 produced no greater response. Formic, propionic and acetic acids sprayed on standing field forage increased DM content 8 to 102, 8 hours after application (Zimmer, 1973). These organic acids change the surface tension of water on the cuticle. This led to the idea that they may act by changing either the structure or hydrophobic nature of the epicuticular waxes. Because formic acid is highly ionic and a strong reducing agent, treatment with this acid might also be expected to disrupt cell membranes (Thaine and Harris, 1973). Formic acid sprayed at .852 of the fresh forage weight was applied in 680 liters of spray/ha to standing alfalfa and al- lowed to wilt the crop for 24 hours before cutting. A con- trol was cut at the same time the standing alfalfa was sprayed. 31 Both treatments were tedded twice daily. The formic acid treatment required a longer time interval to reach a DM safe for storage as hay (Wilkins and Tetlow, 1972). The authors attributed this to a failure of the spray to reach the lower portions of the standing alfalfa. Faster drying of the leaves than the stems may also have limited water removal from the stem.by the stem to leaf transfer mechanism (Wilkins and Tetlow, 1972). They concluded that formic acid could be use- ful as a preharvest desiccant for direct-cut hay crop silage but had little merit as a desiccant in hay_produ¢tion. Increasing Transpiration by Reversible Alteration of Cuticle Surface Waxes Emulsions of olive oil and wood ashes, containing pri- marily potassium carbonate (K2C03), have been used since ca. 60 AD in Greece and Crete to speed the drying ofgrapes to raisins. Two modifications of this process are still widely used in parts of Australia. One, a cold dip uses 1 to 22 grape dipping oil, a mixture of long-chain fatty acids, pri-, marily C16-18’ and esters and sulfated esters of_these fatty acids. These methyl esters are completely emulsified with 4.52 KZCO3 and .52 NaCO3 in water. A five minute dipping time is required. The second method is carried out at 37.7° C. Olive oil or grape dipping oil is floated on top of a 32 sodium bicarbonate (Na2C03), 0.12 sodium hydroxide (NaOH) solution. Dipping time is only momentary (Winkler et a1., 1974). The 32 cold dipping method is preferred because it results in a golden colored raisin with uncracked skin (Grncarevic, 1963). At the present time some grapes are being sprayed before or after picking in certain areas of California. The solution is made of methyl esters of lard or tallow (methyl lardate, or tallow- ate), oleic acid and K2C03 and/or Na2C03 (Petrucci et a1., 1974). Treatment of forages cut for conservation with methyl esters (ME) and/or K2003 to increase drying rates is of recent origin (Tullberg and Angus, 1972; Wieghart et a1., 1980). Re- search on the mechanism of action as understood in grape berries will be briefly reviewed in light of the lack of research in this area for forage crops. Electron micrographs of undipped grape berries show an even distribution of wax platelets oriented perpendicular to the cuticle. Examination of dipped grapes shows a marked flattening of the wax platelets to the surface of the grape berry (Chambers and Possingham, 1963). These authors theo- rized that methyl esters, responsible for this change, may al- low the formation of a continuous aqueous phase between water inside the grape and the outside atmosphere which bypasses the less efficient diffusion through a vapor phase in the undipped grape cuticle. Potassium carbonate may act by saponifying cu— ticular fatty acids, exposing carboxyl groups and changing the hydrophobic properties of surface waxes (Chambers and Possingham, 1963). In addition K2003 may increase cuticular permeability through a pH effect (Schonherr, 1976). 33 Very little wax is actually removed during dipping. Changes in wax platelet structure and increases in drying rate are reversible if the grape berry is washed within the first 12 hours after dipping (Grncarevic, 1963). The gradual de- crease in the effectiveness of the dipping treatment in the later stages of drying may be due to a volatilization of the methyl and ethyl esters (Stafford et a1., 1980). Losses of 72 and 742 of the applied methyl and ethyl esters during dry- ing at 20° C over an l8-day period have been reported. At higher temperatures loss of methyl esters may be much more rapid. Redipping grapes dried in a forced air drier at 43° C at 12 and 24 hours significantly increased drying rate over grapes dipped only once. These authors concluded that the con- centration of ME on the grape surface is an important factor in maintaining elevated drying rates. The possibility that methyl esters increase drying by a covolatilization process is an area which merits further research. Dipping alfalfa in solutions of 0.045 to .72 M K2C03 has been shown to increase drying rates of both stems and leaves under controlled laboratory conditions (Tullberg and Angus, 1972). Drying was maximized at a concentration of .18 M KZCOS' The effect of the dipping treatment was shown to be independent of the length of emersion. No methyl esters were used in these trials because the authors believed that K2C03 was the active ingredient in grape dip emulsions used to increase the drying rate of alfalfa. 34 Spraying solutions of .2, .4 and .6 M K2C03 at 9.52 of fresh weight all significantly increased mean DM content of alfalfa above untreated control and alfalfa sprayed with distilled water in the laboratory. There were no significant differences between levels of carbonate with .2 M K2C03 being as satisfactory as .4 or .6 M K2C03 solutions (Wieghart et a1., 1980). Methyl esters of 012-18 applied along with a surfactant X-77 at 3.8 grams ME per kg fresh forage have been shown to increase mean DM over time in five laboratory trials (Wieghart et a1., 1980). Methyl ester mixtures containing large pro- portions of C16-18 fatty acids were more effective in speeding drying than mixtures containing primarily C12 fatty acids. This difference was especially noticeable in the latter stages of drying perhaps because the shorter chain acids may have been more volatile. The addition of .2 M K2C03 to emulsions of 22 ME in two trials produced a significant increase in drying over the ME - X-77 emulsion alone. At higher concentrations of 3.72 ME the effect of adding K2003 was nonsignificant. The addition of methyl esters and X-77 consistently increased drying rate over K2C03 alone or untreated controls in these laboratory trials. Increasing application rate (AR) five-fold by dip- ping plants in the three component emulsion of ME, X-77, and KZCO3 produced no advantage over spraying these same emulsions at a 102 AR. 35 Increasing the concentration of ME in the three com- ponent spray from 52 to 102 and 152 increased mean DM 2 to 32 for each addition of 52 ME in a linear manner. This sug- gests that although increasing the grams of ME applied per kg forage increases drying rates in the range studied, that the optimal AR of ME will be determined by both economic and biological constraints. Field spraying a .2 M KZCO3 solution on freshly mown alfalfa at an application rate of 3000 l/ha has been shown to significantly increase drying rate over conventional mowing and mower conditioner treatments (Tullberg and Minson, 1978). Further trials comparing application rates of 875 l/ha, 500 l/ha and 200 1/ha to an untreated control showed significant differences between treated and control swaths only at 29 and 32 hours after cutting. Drying rate increased as AR was in- creased but differences were small and nonsignificant (Tull- berg and Minson, 1978). Wieghart et al. (in press) found only nonsignificant increases in mean DM after spraying alfalfa as cut in the field with .4 M.K2CO at a 152 AR. Addition of 0.32 X-77 and 2 to 3 32 ME, supplying 1.7 grams ME per kg forage, produced a sig- nificant increase in mean DM. Increasing grams ME per kg forage from 1.8 to 2.9 or from 2.7 to 3.7 and 7.2 gave a linear but nonsignificant increase in mean DM over the lowest concentration of ME. 36 The effect of a three-component spray on seed stage and 1/10th bloom alfalfa showed that treatment reduced time to reach 752 DM by 7 hours for both maturities. Severity of crimping and the presence or absence of the three-component spray both had a significant effect on mean DM while the interaction of these two factors was nonsignifi- cant. These data suggest that spraying and crimping are not fully additive. Spraying and a light crimping could replace heavy crimping or crushing treatments and subsequently reduce field losses. In vitro dry matter disappearance of treated and con- trol forage after drying have been similar in laboratory or field trials (Wieghart et a1., 1980). OBJECTIVES The overall objective of these studies was to hasten drying of cut forage thereby reducing exposure to adverse environmental conditions that decrease quality. The present research is based on previous investigations by Tullberg and Angus (1972) and (1978), Tullberg and Minson (1978), and Wieghart et a1. (1980), showing that drying of cut alfalfa can be hastened by spray treatments containing potassium carbonate (K2C03) or methyl esters (ME) and K2C03' General objectives and areas of study are listed below. 1. To study the magnitude and consistency of increases in drying rates produced by spraying alfalfa with solutions containing sodium or potassium carbonate or other carbonates and salts of the alkali metals. 2. To clarify the role of ME in hastening drying, and the relationship between K2C03 and different levels of ME in increasing rates of water loss. 3. To determine efficacy of chemical treatment in increasing drying of several other legume and grass forage species of economic importance. 4. To demonstrate the field effectiveness of chemical treatment in reducing the interval from cutting to harvest. 37 38 . And to determine losses of DM and changes in nu- tritive value of alfalfa from cutting through stor- age of baled hay as a function of chemical treat- ment . MATERIALS AND METHODS Laboratory trials utilized greenhouse grown alfalfa to obtain information on the drying of alfalfa when treated with methyl esters (ME) of long chain fatty acids from several sources in combination with potassium carbonate (K2003) or other alkaline salts. The influence of rate of ME and solu- tion application and effect of several emulsifiers (EM) were also studied in preparation for tests in the field. Field trials were conducted under typical hay making conditions as part of a three or four cut management system. These trials utilized conventional field machinery to apply the spray solutions at cutting. Tests were performed under widely varied weather conditions and several environmental variables were monitored during the trial. In addition to measuring changes in DM and water content (WC) over time, as in laboratory trials, apparent respiration losses, har- vesting losses and changes in dry matter and forage quality during storage of baled hay were studied. Laboratory and field trial procedures were different in several regards and will be described separately. Laboratory Procedures Alfalfa was grown in a greenhouse at approximately 20° C with a constant 16 hour photo period. The alfalfa was 39 40 innoculated at seeding with rizobia spp. and was fertilized with the equivalent of 50 lbs P205 and 100 lbs KZO/acre after each cutting. Sufficient water was supplied by over- head automatic waterers twice daily. Spray solution components were mixed on a volume basis for laboratory trials with the exception of K2C03 and the other alkali metal salts which were added by weight to obtain the desired concentration in the final solution. The salt was first dissolved in 50 to 200 mls of distilled water, and then ME and an EM were pipetted into the solution and this mixture was brought to a final volume of 100 to 400 'mls with distilled water.' Solutions were usually used within one day of preparation. Alfalfa was harvested at 10-502 bloom.and within 15 minutes placed in 100 gram.portions on screens for treatment and subsequent drying. The screens were constructed with a frame of Number 9 gauge wire covered with plastic window screening. The screens were numbered and weighed prior to the trial and then the screen plus alfalfa was weighed and either treated or left as a control. Treated material was then reweighed to determine solution application rate. Treatments were applied by spraying solutions over the plants on the screens from a house plant "Mister" at ap- plication rates of l to 42 of the fresh plant weight. The entire screen with alfalfa was then weighed at 2 or 3 hour intervals for the first 12 hours and then weighed at 6 to 8 41 hour intervals until treated hay approached or reached 75 to 802 DM. During the drying process the screens were placed on plastic cafeteria trays to allow a 3 cm space for air movement under the screen. Temperature and relative humidity were recorded each time the screens were weighed using a sta- tionary hygrometer.a At the termination of the trial the plant material on each screen was placed in a separate paper bag and dried at 100° C for 48 hours to determine the final amount of dry matter on each screen. The amount of dry matter on each screen was assumed to be constant from the initial to final weighings. The final weight of DM on each screen was used to calculate the DMZ and WC of the alfalfa at each weighing time during drying. Drying rates were calculated for the intervals between each weighing as the change in WC divided by the change in time, and given the units, change in grams water per hour per gram DM. Calculations were made using a high-speed computer and an iterative fortran program. Field Procedures All solution components for field trials were added on a weight basis with the exception of EM which were added by volume. Solutions were mixed in plastic 5 gallon (18.9 liter) containers which had been previously weighed. Potassium a70.552 Mason's Form Hydrometer, Taylor Instruments, Arden, N. C. 42 carbonate or another alkali salt was weighed and dissolved in approximately 7.6 liters of tap water. The desired weight of ME and volume of EM was then added. The container and solu~ tion was then weighed and brought up to a weight of 19.5 kg, excluding the weight of the container, with tap water. Alfalfa of the Iroquis or Spreader II variety was mowed with a Sperry New Holland haybine;b usually between 9:00 a.m. and noon. Width of cut was 2.9 meters and the baf- fles were set to form either a ldmeter wide windrow or a 2.0 to 2.3-meter wide swath. Solutions were sprayed on the for- age from.two spray booms one mounted 30 cm in front and 35 cm above the crimping rollers and the other mounted 30 cm behind and 35 cm below the rollers. Six low pressure nozzlesc were set 30 cm apart on each spray boom. A six roller pump driven by a hydraulic motor was mounted on the side of the mower and used to pump solutions to the spray booms at 20 to 60 P.S.I. The hay received the spray treatment from the top bar when it was in a thin layer just before being crimped, and just after conditioning, from the bottom spray boom. Application rates were varied by changes in tractor ground speed or nozzle tip size while engine and PTO speed stayed constant at 1900 RPM. Application rates were measured bSperry-New Holland Model No. 488, New Holland, Penn- sylvania. cSpraying Systems Equipment, Nozzles No. 80010L20 or 80015L20. 43 by the change in weight of the solution container after spray- ing a 30.5 meter length of swath and are expressed as a per- cent of fresh forage weight and as grams of ME applied per Kg fresh forage. As each treatment was cut and sprayed 3 to 5 kg of forage was placed on 1.5 by 0.8 meter window screens or 2.75 by 0.92 meter hardware cloth covered screens with a 0.6 cm mesh, in a density that approximated the swath or windrows original density. Screens were fitted with a twine or wire harness attached to each corner of the screen and to a central ring to allow repeated weighings with a 20 pound capacity hanging balance.d The balance was calibrated with 2 and 5 pound weights and screens were weighed before the trial and immediately after placing the forage on the screens. A yield estimate was then made by averaging the weight of 3 randomly selected 3.0 by 2.75 meter section of the swath. The screens were then weighed at two-hour intervals during the first day until 8:00 p.m, and at three-hour intervals the second and third days between the hours of 8:00 a.m~ and 8:00 p;m. Wet and dry bulb temperatures were recorded for each weighing as described in laboratory procedures and pre- cipitation was also measured at each weighing with a rain gaugee mounted on a 0.5 meter stake in the field. Average dHanson Hanging Balance Scale Model 842, Nasco Ft. Atkinson, WI. eTrue-Chek Rain Gauge, Tru-Zol Edwards Mfg. Co., Albert Lea,‘Minn. 44 wind speed and minutes of sun each day were obtained from Capital City Airport 12 km to the northwest of the field site. Field trials were terminated when sprayed material reached 75-802 DM. All the material from each screen was placed in an individual paper bag and dried at 85-95° C for 48 hours to determine the final weight of DM on each screen. Percent DM, WC and drying rates were calculated as described for laboratory trials. 45 Application of Chemicals to Increase Drying of Cut Forage Under Laboratory and Field Conditions Thirty laboratory and 35 field trials exploring the use of chemical treatments to hasten drying of forages were conducted. Many of the areas of interest presented earlier in the objectives sections were explored under both labora- tory and field conditions, and several replications usually were performed. Specific laboratory or field methods differ- ing from the general procedures outlined above will be pre- sented together under the subject area heading. Laboratory and field trials are distinguished by the prefix (L) for lab- oratory and (F) for field, followed by a chronological trial number. Trial and table numbers for each area of study will be specified. Hasteninngorage Drying with Carbonates and Other Salts of the Alkali Metal Group Alkali metal carbonates solutions alone and in combina- tion with methyl esters (ME) and an emulsifier (EM) were tested for effectiveness for increasing mean DM and drying rates (DRt) of alfalfa in trials L2, L15, L21, L22, L23, L27, F8, F12, F23 and F25. Influence of solution pH and anion type on speed of water removal were studied by utilizing .4 normal solutions of the chloride, carbonate and hydroxide salts of 46 sodium and potassiumf in trials L15, L19, L20, L27, F23 and F25. The pH of K2C03 and KOH solutions were adjusted to pH 9 to 11 by the addition of ammonium carbonate in L19 and L20 or Hydrochloric Acid (HCl) in trial L27 Solution pH was mea- sured by the use of a glass electrode attached to a Orion Research pH meter that had been standardized with pH 7 and pH 10 buffers. Data from these trials are presented in Tables 2 and 3. Influence of Methyl Ester Source and Composition Methyl esters and other lipids (Table 6) combined with alkali salts were compared in Trials L1, L18 and L28. In trial L18, a concentrated solution of potassium hydroxide (KOH) was prepared by mixing 11.2 grams KOH with 60 mls of distilled water, 20 mls olive oil, and 20 mls of ethanol. The ‘mixture was stirred, covered, and allowed to stand for 10 hours. Four hundred mls of distilled water, 1.0 ml X77 and 0.8 ml oleic acid were added to obtain an emulsion of 42 lipid, .4M KOH, .252 X-77, and .22 oleic acid (treatment number 5, Table 7). Another solution containing olive oil was prepared 2 hours before the trial by dissolving 5.53 grams K2003 in 191 mls distilled water and adding 8 mls of olive oil and .5 mls X-77 and .4 mls oleic acid (treatment 4, L18, Table 7). fAnalytical reagents Mallinckrodt, Inc., Paris, Ky 40361, used in laboratory trials. Industrial grade Na CO3 and K2C03, Allied Chemical Co, Morristown, N.J., used in field trials. 47 Emulsifiers and Surfactants Importance in Solution Formulation and Forage Drying The effect of various emulsifiers (Table 6) on stability of lipid water emulsions, and drying of forage sprayed with these solutions were examined in trials L6, L8, L10, L12, F17, F26 and F27, Table 8. Combined Effects of Potassium Carbonate and Methyl Esters Trials L13, L14, F11, F20, F21, F22, F24, F29, F32, F33 and F34 examined the effectiveness of K2003, emulsified ME or a combination of these components for hastening drying of cut alfalfa. A 2x2 factorial design and orthogonal con- trasts were used in trials L14 and F34 to determine main ef- fects of both K2C03 and ME and to check for interaction between the effect of these two components on plant drying. Results, details of solution application, and conditions during drying are presented in Tables 8, 9, 10, and 11. Optimum Amounts of Methyl Ester Addition Rate of ME application was increased by elevating the concentration of emulsified ME in a .2M K2C03 solution, while total volume of liquid applied remained constant in trials L4, L9, F7, F21, F22, F29 and F32. Description of solution con- centrations, application rates and measure of subsequent dry- ing are presented in Table 12. 48 Influence of Changing Liqpid Application Rate and Spray Pump Pressure on Forage Drying Liquid application rates were increased while amount of ME K2C03 and EM were usually maintained constant by de- creasing their concentration in the spray solution. Increases in liquid application rates were obtained by changing tractor ground speed (F15 and F18), changing nozzle tip size (F26 and F27) or by changing flow rate to the spray booms (F35). In two trials (F16 and F18) spray pump pressure was elevated by limiting return of solution through the agitation hose. Application rates were held approximately constant by changes in tractor ground speed. Description of solutions, application rates and pump pressures are presented in Table 13. Chemical Treatment of Different Forage Species and Plants in Different Physiological States Drying of Red Clover (RC), Alfalfa (Alf), and Birdsfoot Trefoil (Bft), sprayed with the three component solution or left as control were compared using several methods of ex- pressing results in trial L17 (Table 14). Drying rates and Mean DM content of brome and orchard grass at vegetative and seed stages of maturity were compared to alfalfa in trials L32 and L34 (Tables 15 and 16). Influence of the addition of crop oil concentrate to the three component 49 solution sprayed on mixtures of brome and orchard grass was investigated in trials L12 and L26 (Table 15). Rates of moisture loss and responses to treatment were determined for alfalfa grown under field and green house en- vironments in late fall and early spring (trials L11 and L16, Tables 15 and 16). Physical characteristics, period of growth, and initial DM content for these alfalfas are pre- sented in Table 17. Influence of Chemical Treatment on Length of Field Drying, and Losses of Dry Matter and Nutrients Durinngarvest and Storage Changes in DM content and drying rates over time for alfalfa placed in 1.0 meter wide windrows or 2.3 meter wide swaths were studied in trials F3 and F9, results are presented in Tables 18 and 19. Apparent respiration losses for sprayed and control for- ages were measured in 8 field trials during the summers of 1980 and 1981. The initial amount of dry matter on each screen was determined by taking a composite of three initial DM grab samples from each swath or windrow immediately after mowing. These samples were then frozen on dry ice in 1980 or heated in a micro wave oven for l . 5 minutes in 1981, to deactivate respiratory enzymes, and then dried for 24 hours at 100° C to determine initial DMZ. The initial weight of DM on each screen was then calculated 50 as the initial DM2 X initial forage weight. The final amount of dry matter on each screen was determined as described previous- ly. The change in amount of dry matter during drying was termed apparent respiration loss. This was then expressed as a percentage change from the initial weight of DM. Apparent respiration loss, mean DM content and hours to reach 752 DM are presented for trials F7, F9, F10, F13, F26, F27, F34, and F35 in Table 20. DM loss after mowing and raking was compared for sprayed and control hay raked at 60 to 652 DM in trial F35. Losses ‘were estimated by two methods. The first method involved picking up leaf and stem parts from 3 randomly assigned square meter areas after raking with a roller barg side delivery rake at 3.5 map.h. The second method utilized a shop vacuum cleanerh which was used to collect residual material from 3 randomly chosen meter square areas. Because the vacuum picked up trash from previous cuttings as well as newly shattered material, a ‘measure of the original residue was made by removing hay soon after it was cut, from.three one meter square areas by hand and the original residues and forage dislodged during mowing va- cuumed up. Raking loss was then determined by difference. Samples were dried at 100° C for 48 hours and weighed to deter- mine loss per square meter. Total DM loss from.mowing and/or gInternational Harvester Model No. 35. hSears Home-Shop Vac. Model No. 758.17885. 51 raking was then calculated in kg per Ha and as a 2 of total DM yield at cutting, results are presented in Table 21. A series of trials were conducted to determine losses _of DM and changes in analytical values during storage of con- trol and sprayed baled alfalfa. In the first set of tests all swaths were raked when treated material reached 60 to 652 DM and were baled when treated hay reached 75 to 802 DM. The second set of trials were designed to compare interval to baling, analytical values of sprayed and unsprayed hay as baled, and changes in visual and analytical quality measure- ments for treated and control hay baled at the same DM content. Ten to 12 bales per treatment were core sampled, weighed usually fitted with thermocouples and stacked under cover. Temperatures were monitored 2 or 3 times weekly for 3 to 4 weeks. When bale temperatures stabilized near ambient tempera- ture the bales were reweighed core sampled and visually examined for mold growth and color changes. Core samples were frozen immediately and stored at -5° C until analyzed for DM, ash, water soluble carbohydrate, In vitro DM disappearance (IvDMD), and fiber and nitrogen fractions using standard laboratory pro- cedures. Losses of dry matter were calculated by multiplying the total bale weights for each treatment by their respective DMZ, the final weight of DM was then subtracted from the initial weight of DM for each set of bales, and this change expressed 52 as a percent of the initial weight of DM that entered into storage. Results are presented in Tables 22, 23 and 24. Laboratory Analysis Dry matter percent of initial-cut forage samples and bale samples were determined by oven drying at 100° C for 24 hours. Neutral and acid detergent fiber analysis by the methods of Goering and Van Soest (1970) and Kjeldahl nitrogen and ash by the AOAC methods (1970). In vitro dry matter disappearance (IVDMD) was by a modified terry-tilly pepsin digestion (Tinnmet and Thomas, 1974) and water soluble carbohydrates by a modi- fied method of Dobois et a1. (1951). Experimental Design and Statistical Analysis A split plot repeat measurement design was employed for the drying trials. Data were analyzed by analysis of variance, and Bonferroni-t or designed orthogonal contrasts were used to evaluate differences between treatment DM or drying rate means for all replicates and all weighings. Linear and quadratic functions were tested for fit in trials L9, F7, F29 and F32 where application rates of ME were increased to test for a dose response. The students-t test was used in bale storage trials to evaluate differences in mean or maximum bale temperatures for the means of all replicates for each treatment over the storage period. RESULTS AND DISCUSSION Drying of Alfalfa Treated with Carbonates and Other Salts of the Alkali Metal Group Solutions of sodium or potassium carbonate sprayed on alfalfa usually increased mean DM content above control (p<.05) in L15, Table 2, and F12, Table 3, and at P<.01 in trial L21, Table 2. In trial L22, Table 2, sodium carbonate (NaZCOB) did not hasten drying while potassium carbonate (KZCOB) in- creased (P<.Ol) mean DM. Where forage was approximately 602 grass in trial F23, Table 2, neither Na2C03 or KZCO3 increased mean DM.above untreated control (p>.20). Forage treated with K2003 had a greater mean DM than did Na2C03 treated material in two trials (P<.05) L22, Table 2, and F12, Table 3. The trend for faster drying of forage sprayed with K2003 than that sprayed with Na2CO3 was also apparent when these salts were combined with low levels of methyl esters (ME) and an emul- sifier (EM) (55.8 > 51.82 Mean DM at P>.20 in trial L2, Table 2) and was significant (P<.05) in L23, Table l, and F8, Table 2. In 4 out of 5 laboratory, and 2 out of 4 field trials mean DM of K2003 sprayed forage exceeded that for Na2C03 sprayed material. In 2 laboratory and 2 field trials differ- ences exceeded P4105. Sodium carbonate treatments had mean DM contents similar or slightly greater (P>.20) than K2C03 53 54 treated material in 3 trials F25, Table 3, and L15 and L21, Table 2. Iburs required for both control and sprayed alfalfa to attain 752 DM were usually greater in field trials than lab- oratory trials, often not reaching 752 DM in 40 to 50 hours. This difference is primarily due to cessation of drying dur- ing night periods in field trials while forage continued to lose water over night under laboratory conditions. Although Na2C03 and K2C03 are the least expensive and most available carbonates of the alkali metal group, carbon- ates of other alkali metals were also tested. In two out of three trials (L22 and L23, Table 2) the ranking of these ele- ments from least to most effective was Li a N.NN N.NN o.N o N N.NN NooNM 5N. s No.vm a m> N.N N.NN N.NN N.NN o N N.NN Noonz 5N. N No.vm s m> N N.NN N.NN. N.NN o N - NooNNN aN. N No.vm N.N.s.N.N m> N N.NN N.NN. N.NN o o - «:02 N NNN N.NN N.NN o.N o N - NooNNo 5N. N No.va N m> N N.NN N.NN N.N o N - NouNaa 8N. a NN.vm a m> N N.NN N.NN N.NN o N - NooNN.sN. N mmz N m> N N.NN N.NN N.NN o N - Noonz 5N. N No.vm N.s.N.N m> N N.NN N.NN N.NN o o - maoz N NNN No.va N m> N Nz s m> N N.NN N.NN NN o N N.NN mos as. N mNz N m> s N.NN on NN o N N.NN NooNx 3N. a oN.vm N m> N N.NN on. N.NN o N N.NN momz as. N No.vm s.N m> N N.NN NNA NN o N N.NN Noonz aN. N No.vm s.N m> N.N N.NN NNA N.NN o o - maoz N NNN coNuomumucH so cams been so so owmemzuw em aoNNANNono aN NNNNH mummuuaoo u Naouuomcom comm: nomom ou whoom doom Goaumowa ¢ cowuoaom unmaumoue NNmumz NmeNa «an No.muNmN guano New mmumnonumo NuNs poumoue.mmaoma< mo muoumamumm.waahua wawumma muooawuooxm muououonmq .N manna 56 mnume~.+mZNN NNN. N.NN N.NN N.N s. N N.NN NouNmo 8N. N NN-NNNN.+mzNN NON. N.NN N.NN N.N s. N N.NN NooNNa 5N. N NN-NNNN.+mzNN mNz N.N m> s NNN. N.NN N.NN N.N a. N N.NN NooNN 5N. a NN-NNNN.+mzNN No.va a m> N .N NNN. N.NN ONA N.N s. N N.NN NoUNmz 8N. N NN-NNNN.+mzNN No.vN s m> N NNN. N.NN NNA N\N s. N N.NN NOQNNN 5N. N No.vm N.N.N.N.N m> N NNN. N.NN NNA N.N o o - mcoz N NNN NN-NNN.+mzNN Nz N.N m> N N.NN NN N NN.N N.N N.N N.NN + NooNN aN. a NN-NNN.+mzNN mNz s m> N N.NN NN N NN. N.N N.N N.NN + NooNaz aN. N NN-NNN.+N2NN No.vm N m> N N.NN ON N ON. N.N N.N N.NN + NoUNNN 5N. N No.vm N.N m> N N.NN NN NN - o o - meoz N NN msNumm omx\mzumlmwu :9 saw: Name use ozaNNN examee UNcONumu . mama am coNuaNuomma oN NmNue mononucoo u Ncouuomaom pmcmoz Sodom ou muaom coaumowaaom .Hom uamaumoua .emscNucoo .N «None 57 N.NN N.NN N.N o N N.NN max 5N. N N.NN N.NN N.N o N N.N NoomNNmstN. Nz N N> N + o N sN. N N.“ a N m> N N.NN N.NN N.N o N N.NN Nmomz aN. + NN.N 5N. N No.va N.N m> N N.NN N.NN. N.N N N N.N NooNNNmzcaN. N NN.vm N.N.N.N N> N N.NN N.NNA N.N o o - acoz N NNN NN.vm N N> N No.vm N N> N No.vm N N> N Nz N N> N N.NN NNA N.NN o N N.NN . mos aN. N Nz N m> N N.NN NNA N.NN o N N.NN Noe + mos sN. N No.vm N N> N . . . . Nz N N> N N NN NNA N NN o N N N Nos aN N mNz N.N m> N N.NN NNA N.NN o N N.NN momz aN. N Hocvm cam m> muN N.O¢ WQA N.NH o N N.N Homz 8%. N EONuomumueN N.NN NNA N.NN N o - oeoz N NNN 2a cam: see an NNN use new owx\mzuw am am eoNuaNuonn oN NmNua mUwQHUGOU U HCOHmeaom flammz SUNQM CU WHSOE mum“ SOHUNOHH 4 aOHUSHOm UQOSUNGHH. .pooawucoo .N manna 58 .unwwm3 owmuom nmouw wx Hon powaaam mumumo ahnuma mo mamuu .o~.Amo .moumoNHQoH q mo noose .unwao3 madame Hmuou mo mwmucoouom o no udoucoo Houuma Nun n 290 n .oanmB owmuow noonm mo owoucoouom o no poaaamm momma mo oaoao>o N.NN N.NN N.NN N. N N.NN RLNNNN. + BNNN NooNNNmzcaN. mom 5N. N Nz N N> N.NN N.NN N.NN N. N N.NN NN-NNNN.+ mzNN + mom 5N. N mNz N 3 N.NN N.NN N.NN N. N N.NN NTxNNm. +§NN cox 3N. N NN-xNNN. No.vm N.N.N m> N.NN N.NN N.NN N. N N.N + m: NN N No.vm N.N.N.N N> N.NN N.NN N.NN o o - meoz N NNN so saw: can 2: mm“ use new amx\mzNw mm rm aoNNANuommn oN NNNNN mummuucou u Naomuowaom booms Sodom on chaos comm cowuoowa < cowuoaom ucoauooua .NmsaNucoo .N «Name nuumeN. + mz_Nm N.NN NNA N.N NNNNNNN N.N N.N + NNNNN eN. N NN.N N a, NNN NN....NNN. + m: NN mmz N N> N.NN NN. N.N 50 N. NN. N.N + NouNmz aN. N NN.vN N m> N.NN NNA N.N N .NN N N maoz N Na N.NN N.NN N.N NNNNN\N N N.N NON aN. N Nz N N> N.NN N.NN N.N NAN N.NN N N.N NNNNN 5N. N NNN Nz N N.N N.NN N.NN N.N .8 NN. N N.N NNNNmzsN. N NNN mango mNz N.N.N N> N.NN N.NN N.N o .NN N N maoz N NNN N.NN NN N NN\NN\N N N.N NNNNM aN. N sax NN NN.vN N m> N.NN NN N NNN N N.N NNNNNz sN. N 80 O NN.vN N.N m> N.NN NN N.N N .NN N N «:02 N NNN so emu: use so NMN use new mmumn chuumum nwx\msz m coNuaNuumon mumouuaoo o Naouuomcom ufiomz snowed ou whoox w mumnumo3 comm coaumowa < ucoauomue 0H downy masons Hamxa< may mo muHmm monuo pom mouoconuoo nuwz pouooue mmamma< mo muouoamhmm wcfiwun wcwumoe NHMNNH madam .N NNNNN muoumawucmo Houou ..a.m ooum poo .E.m ooum floo3uon moauwpflson o>wumaou paw ououmuomaou cmoz 60 .mpOHNoo onwwo wcwpoaocfl .ucoucoo Zn poNMNooom ozu tummy ou powwocou muoni n .NNNNN NNNNN mo some chuuNuNw .Ndon Hod muouofioHNx aw Hmwuu oufiuco onu wcauop woman pcfi3 owmuo>m .HoNHu onu wcwuop cash mo m .moumowamou m mo amuse .aOHumcmaoxo How H manna oomo.o.n.o 55:53. + E NN mew m.m~ o.m mm. . N.N moxEN. N wnnxwmmm + mz.N~ NN..v.N N m> N.N N.NN N.NN N.N NN. N.N + 8NNNsN. N sax N.NN NN-NNNN. + m: NN Nz N N> N N.NN N.NN N.N NNN NN. N.N + NNNN z 5N. N Bo o.o mo.vm N.m.~ m> H N.mN m.o~ o.N 0 com o o oaoz H mmm so new: use an RNA own NNN mouse waNuNmum wa\mznm mm :oNuaNuona mononucou u Ncouuomaom mono: snowed ou capo: w muonumoz comm coauoowa < unmauooua QH Howue I, Ill ll" .NmscNueoo .N «Name 61 due to an added effect of the potassium ion on the plant stomata. The concentration of intracellular potassium ions in the guard cells regulate stomatal appature and thus tran- spiration rates in the growing plant (Fisher, 1968). Potas- sium ions in the spray solution could have been preferentially absorbed into the unprotected guard cells, causing opening of the stomata. If this were the primary mode of action for K2C03 or the other carbonates of the alkali metals, greatly increased Drt during the first few hours after treatment followed by an abrupt decrease in water loss rates similar to those reported for alfalfa treated with fusicoccin (Stalfet, 1957) and sodium azide (Tullberg and Angus, 1972) would be expected. Drying rates for alfalfa treated with any of the alkali metal carbonates excluding lithium were greater than for un- treated control during the first six hours of drying in trials L21, L22, and L23, Table 4. During the first two hours after treatment CsZCO3 or Rb2003 treated alfalfa had the highest drying rate with the other carbonates ranking in an order similar to how they had been ranked for effectiveness in in- creasing mean DM. Because CsZCO3 was generally more effective than K2CO3 during the initial 2 hours of drying, little evidence exists for a preferential effect of potassium ions on guard cell mediated stomatal opening. The maintenance of drying rates greater than untreated controls during the first 6 hours after treatment with alkali metal carbonates suggest that the 62 Table 4. Drying Rates During Given Periods Post-Cutting for Three Laboratory Trials, Drying Ratea Trial Treatment 0 to 27hr 2 to 4 hrD 4 to 6 hr L21 None .523 .308 .205 .2m NaZCO3 .550 .361 .222 .2m KZCO3 .543 .308 .227 .2m Rb2C03 .653 .413 .253 .2m CSZCO3 .540 .383 .242 L22 None .170 .132 .092 .2m Li2C03 .143 .122 .090 .2m Na2C03 .197 .152 .097 .2m K2CO3 .213 .180 .134 .2m Rb2CO3 .203 .203 .140 .2m 082003 .235 .270 .142 L23 None .163 .120 .115 .2m Li CO 22 ME +3EM .193 .133 .132 .2mNa2CO3 22 ME + EM .171 .138 .135 .2m K CO 22 NE i EM .329 .220 .178 .2m Rb CO 22 ME +3EM .271 .209 .162 .2m Cs CO 22 ME +3EM .341 .260 .148 aDrying rate, loss in grams water per hour per gram.DM. Hr. = hour post-cutting. 63 principal action of these compounds is on the plant cuticle rather than on stomatal appature alone. These data tend to support the work of Schroher (1976) where he ranked the alkali metal ions ability to increase per- meability of isolated citrus cuticles in the order of increas- ing ionic radius (Li < Na < K < Rb). The author suggested that increases in water permeability were a result of enlarge- ment of polar pores in the cutin matrix due to preferential association of the largest alkali metal cations, having the lowest charge density, with non-esterified carboxyl groups. The alkali metals have larger ionic radii and lower first ioni- zation energies than any other group of elements. Within the alkali metal group ionic radius increases and first ionization energy decreases from lithium to cesium (Table 5). Table 5. Ionic Radii. and First Ionization Energies of the Alkali Metals Alkali Metal Ion Ionic Radius First Ionization Energy ______1r_____ A IKcalsimoleb Li .60 126 Na .95 120 K 1.33 102 Rb 1.48 98 Cs 1.69 90 aAngstrom. b Kilo calories per mole. 64 Whether increases in drying of intact alfalfa plants sprayed with solutions containing alkali metal ions are due to similar changes in cutin matrix pore size, or to changes in epicuticular or imbedded waxes is not clear. Perhaps re- moval of surface waxes with petrolium.ether and subsequent treatment with carbonate solutions could provide an answer. The work of Schroner (1976), implicating increases in Ph as an important factor in alkali metal mediated changes in cuticular permeability led to examination of the influence of solution Ph and anions on drying of alfalfa. Interactions between the effects of cation (K+ or Na+) and solution Ph (11 or 13) were detected in both L15, (P<.05) and in L27, (P<.01), Table 2. Mean DM of Na2C03 treated alfalfa was greater than that of NaOH treated alfalfa (38.7 > 35.6 at P<.10, L15, Table 2). Yet mean DM of K2C03 treated alfalfa was less than that of KOH treated material (52.7 < 56.3 at P<.10 in F25, Table 3, and 39.5 < 41.5 in L15, Table 2, and 44.8 < 46.0 in F23, Table 3, at P>.20). Mean DM of KOH treated alfalfa was greater than that of NaOH treated alfalfa in two trials (41.5 > 35.6 at P<.01 in L15 and 43.47 > 39.9 at P<.10 in L27, Table 2). In L27 solutions of sodium or potassium chloride (NaCl) or (KCl), Ph 7, KOH titrated to Ph 11 with hydrochloric acid (HCl) and NaOH, at Ph 13, failed to increase (P>.20) mean DM above untreated control. Sodium chloride treatment had greater mean DM than did KCl (P<.05) which is not consistent with re- sults comparing sodium and potassium salts at Ph 11 and 13. 65 A solution of ammonium carbonate, Ph 8 was less ef- fective in increasing mean DM than a KZCOB’ NaOH solution at Ph 13, or a KOH solution at Ph 13.5 (53.1 < 56.1 and 56.4 at P<.05 in trial L19, Table 2). The addition of ammonium car- bonate to a K2003 solution or to an emulsified ME, KOH mixture decreased Ph from 11.3 to 9.5 and from 13.5 to 10.5 respectively in trials L19 and L20, Table 2. These reductions in Ph, due to release of ammonia gas and hydrogen ions, also tended to diminish the magnitude of increases in mean DM from treatment of alfalfa with K2C03 or KOH solutions (55.6 < 56.1 at P=.20 in L19 and 47.2 < 49.2 at P>.20 in L20). Although there was considerable variability between the results of trials L15 and L27, several major trends are apparent that may help to explain the detected interactions. Solutions containing sodium salts were similar in effective- ness between Ph 7 and 13, While mean DM of alfalfa treated with solutions containing potassium salts increased as the Ph of the solution increased within this same range. Potassium.hydroxide was the most effective alkali metal salt in 5 out of the 6 trials where it was tested. The ef- fectiveness of KOH solutions was diminished when Ph was de- creased by addition of HCl or ammonium carbonate suggesting that high solution Ph may 1) facilitate movement of the po- tassium ion into the cuticle by disruption of surface waxes or 2) may directly cause extensive hydrolization of ester linkages within the cutin matrix. 66 Influence of Methyl Ester Source and Composition Different methyl esters (ME) with similar fatty acid distributions were screened for effectiveness in hastening the drying of alfalfa (Table 6). Methyl tallowate, methyl lardate, and methyl oleate in combination with KZCO3 and an emulsifier (EM) all increased mean DM over untreated control alfalfa (P<.01), but were not different from each other (P>.20; Ll, Table 7). Food grade methyl tallowate, or lardate, indus- trial grade soap stock of unknown composition, and olive oil emulsions, all in combination with KZCO3’ increased mean DM content of alfalfa above untreated control (P<.05; L18, L28, and L34, Table 7). Methyl esters of lard and tallow were more effective than soap stock (P<.20; L28) but were not different from two olive oil preparations (P>.20; L18, Table 7). These trials indicate that lipids of both plant and animal origin containing primarily C16 and 018 fatty acids are of similar effectiveness in increasing drying, while the soap stock tested appears to have less pronounced effects on plant drying. Further research appears warranted on identifica- tion of other effective low cost lipid preparations that will increase plant drying rates. .vmh .o ..h.z .wo3nom ..ocH ..00 new gum: ..om gum .moma .xmocH xuoz Eonm pocwouno mmoao>s .bmmom oooNoHoo .ocmao>oq ..ocH .mmwuumoocH osmHo>oqa x .NNH .xoouoxmo ..oo mcfluonwuumwo oNnEow can Houooum Scum nonwounon .Nmmmv oNno .Nuoccwocflu ..o>< oumm come ..oaH .mmfiuumoocH wnofim Bonn poswmuoON .NNNNN «o .oomNoamNa cam .conN>No oeNNo ..oo NmoNEmeo cou>mno .3\3 we .mUNm cowumNoENOM N3\3 woa .muomuommuomn3\3 mom .mconumoouoam Nouuom Aoumuucmosoo HNO mouov HxMENnuwm .NocomoumomN pom .mcwoo huuom comm .mHOOMHm .mcoawnumxowaom Hoahxad xhh I x mucomd chooNuooom Homaocflnm axooum doom N NN N N N N N NN-NN NNNuNNN N.N-N. sNNo m>NNo N NN NN NN N N - - - - NNNNN me .1 NN NN N N N N N N.NN - N.NNN NoNoa onNo ,0 . N NNN N N N N NN NN-NN - N.N NNNNum NmommNo Nmeums N NN NN NN N N N NN-NN NNNumNN N mumonma NNNNuo NNNeumz N NN NN NN N N . NN-NN NNN-NNN N NNNNum mumsoNNma NNNaumz uuuuuuuuuuu Nmuou No N -uunuuuuuun u o o . N.NNo N.NNo NNo NNo NNo NN-No ucNom mst> mst> maNm> aumcmN :Nmno oNoa Nuumm meNuNmz chNoN eoNumonNeoamm oNoa . X62 .mCONuoHom Nahum CH pom: mHonNmHQEm can mpHQNA Honuo .Houmm ahnuoz mo :owuamomfioo .m manna 68 N.NN om N.N m. m ofiom cacao mmm. + hhlx «mm. + mom SN. + mmOEN we + Ado m>HHO we m mz N.N m> m.m m.mm Hm m.h m. m oflom owoao mmm. + hhnx mmm. + NooNs 2N. + NNo m>NNo NN N mz m m> v m.wm om o.m m. N Owo< cam O wmm. + Nana NNN. + ooNs 2N. + mumoNNN Nachos NN N mz m m> N N.NN mm m.m m. m pend owoao wmm. + NNIx NNN. + NooNs 2N. + mumsoNNme Nagpur NN N NN.vm N.N.N.N m> N N.NN NNA NN N N mcoz N NNN N.NN NN N.NN N.N N.N NN-N NN. + NooNN 2N. + unwound Hanan: Nb m N.NN NN N.NN N.N N.N asux NN. + NooNs 2N. + mumsoNNme Nmeumz NN N m2 N.N m> m N.NN o.om m.oa N.N m.m shux wm. + moomx 2N. + ouooao ahzuoz Nu m mmz m m> N H.h¢ o.hm N.OH m.~ m.m m N hhlx mm + 00 & SN. + mawame wb N No.vm m.v.m.~ m> N h.mm o.omA o.mH o o 0:02 ,N HA so coo: so so so wmrlpzo mow omxmeHm ow coaumfluomoo usosuooua oH NMNHB mumonucou u Ncouuomsom coco: somom ON muoom comm cowumowdmmm .NeNNNNaam NNaNN New muoumm Hhcuoz unouomman chumoH mflmwua huoomuonmq How muouoaoumm wawhun mo coaudfiuomon .5 dance 69 oHOH—mnum " 38mm .onNN umnuo no umumm Hanumz n m: .mcowuwcmmem How H wanna 0mm w m~c~o~nhm N.NN omA N.NN o N Noon 2N. m NNIx NmN. + mouNm 2N. o.mm omA N.¢N «. N + xooum mmom NN v NN-N NmN. + mooNx 2N. ON.vN ¢ m> N.N m.o¢ omA N.NN e. N + ouncumg Hanna: NN N NNux NmN. + mooNx 2N. oN.vm N.N.N m> m m.Nm omA N.NN v. N + mumzoaame Nasumz «N N mo.vm m.¢.N.N m> N m.Nm omA N.NN mcoz N NNN cNom onNo NmN. + NN-N NmN. + mom 2v. + o.N¢ NNA NH m. N omoam «q + HNo m>NNo NN m <0 N N. + Nuux NmN. + oon N.NN NNA NH N. N 2N. + NNo o>NNo NN q . . men+ m z m g e Rux NmN. + moo m 2N. mo.vm N m> N m.mv NN m m. N mumzoaamu Hague: aw m No.vm m.¢.m m> N N.NN NNA ma o N NooNx 2N. N .m.z N m> H «.mm NNA NH o o maoz N mmq Sn cams co SQ 2a wmh DEG wow aux\m2Ho w coflumwuommo usmfiummus DH Hmwua mummnucoo u waonummaom ocmmz sommm ou mason mama Godumowamm¢ .cmscNuaou .N oNnma 70 The Effectiveness of Various Emulsifiers and Surfactants In . Maintaining Lipid Water Emulsions and Speeding Drying The addition of 0.05 to 0.8% x-77, oleic acid (0A) or crop oil concentrate (CDC) to solutions containing up to 20% ME produced a white colored, visually complete, emulsion of lipid and water that was stable for up to 7 minutes without agitation. In two trials the addition of 0.4% CA (L6) or 0.8% CA or X-77 (L8) to a 20% ME, water mixture tended to increase mean DM of sprayed alfalfa above treatment with MB or ME plus K CO 2 alone (P<.20; Table 8). There was a trend for CA to be more 3 effective than X-77 in increasing drying in trial L6 (P<.10) while in trial L8 0.8% x-77 appeared to be more effective than 0.8% CA, although these differences lacked statistical signifi- cance (P>.20). Crop oil concentrate substituted for X-77 inar10% ME .2 M K CO .25% X-77 solution increased mean DM of sprayed al- 2 3' falfa above the solution containing X-77 (P<.05; trial L10, Table 8). This trend was also apparent in F17 (P>.20) though differences in application rate and several light rains during the trial confound these results. In two field trials the addition of a mixture of X-77 and 0A to K2C03 4 in trials F26 and F27, Table 8). solutions did not hasten drying (treatments 2 vs Both observational and drying trials indicate that the addition of a surface active agent to solutions containing ME 71 O.NN NNA ON N N mum—pg :5 mod NN. + NooNx 2N. m2 NON N N.NN NNA N.N N N Bmfifinbmdomouo NNN. + ooNx 2N. m2 NON N NO.vN N.N m> N N.NN NNA NN N N N NNux NNN. + ooNx 2N. m: NON N NO.vN N.N.N m> N N.ON NNA NN O O ocoz N ONN N.NN O.NN O.NN N N No onNo NN. + on N 2N. + m: NON N mz N m> N N.NN O.NN N.NN N N N N NNux NO. + on N 2N. + m2 NON N mz N m> N N.NN O.NN N.NN N N NNnx NN. + m2 NON N ON.vN N.N.N m> N N.NN O.NNA O.NN N N m: NON N ON.vm N.N.N.N m> N N.NN O.NNA O.NN O O mnoz N ON N.NN N.NN O.N N.N N.N 40 NNW + NN-N NN. + ooNx 2N. m2 NON N ON.vm N.N m> N N.NN O.NN N.N N.N N.N cNma ONmNo NN. + ooNN 2N. ms NON N ON.vm N m> N N.NN N.NN N.N N.N N.N N NN-N NN. + oon 2N. m2 NON N mmz N.N.N m> N N.NN O.NN N.N N.N N.N NooNN 2N. m: NON N NN 2o saw: no so so NNN use NON nmx\mzum N coNumNuomma u:m&ummue ON NmNua nummuucou p Ncouummcom comm: nommm ou muse: mNmm coNumoNNmma .mconNaam kumm Nanumz can mumconumo nuwz cmummua MMNMMN¢ mo madame mcflcmummm :N mmmcm>auommmm ucmuomwuom can an wwwmesem .m mfinma 72 .mumu CONumoaNmmm mo mumENummU .coaumcmamxw Now N magma mom .83398 NON N 3nt wows.m.u 0.0.056 NO.XN N 9 N N.NN O.NN O.N O N.N tux NNN. + N8NON 2N. + m: NN N . H. DAG . NO vm N 9 N N.NN N.NN N.N O O.N v.2 NM“ M. H Hm\¢N\o MOUNM SN. v NO.xN N .3 N N.NN O.NN N.N fix N NN O NN.N momz 2N. + NNN N8NNN 2N. N NO.XN N .3 N O.NN O.NN N.N 5 0.0 O NUO.N N82 2N. N NO.XN N.N.N.N m> N O.NN O.NN N.N. o oNN O O mcoz N NN.N NN-N NNN. + N.NN O.NN O.N NN. O.N N89 zN N2 NN N mz N m> N N.NN N.NN N.N O N.N tux NN. + NN\NN\N Hum QmmNo NN.+ fix N.NN 8NN 2N. N mz N E N N.NN O.NN O.N NNN O N.N N8Nx 2N. N mz N E N N.NN O.NN N.N so O.O O N.N N8NN 2N. N NO.XN N.N.N.N m> N N.NN O.NN O.N o oNN O O 982 N NN.N N.NN NNA 3;; mm. N.N BESS . N8 980 NNN. + c9. N ON N8NN 2N. m: NN N 3.2 N m> N N.NN NNA NNN NN. N.N NN.N NNN. + =6 N.N NooNx 2N. mzNN N NO.vm N.N m> N N\NN . NNA u NNN O O mcoz N NNN so saw: so so an N w,ozo NON sauna chuumum nuxxmznm N :oNNmNuomma oN NNNua munmuucou u Nconummcom ocmmz nomom ou muaom onmnummz oumm cowumowammd ucmeummua .Omscwucoo .m manna 73 provided a more uniform emulsion which tended to be more ef- fective than ME or ME plus K2C03 solutions alone for increas- ing drying. On the other hand the effectiveness of K2C03 solu- tions was not enhanced by the addition of surface active agents. Therefore, in subsequent trials an emulsifier was added to all solutions containing ME, but were not included in solutions containing only K2C03 or other salts. Additive Effects of Methyl Esters and Potassium Carbonate Combining emulsified methyl esters (ME) with potassium carbonate (K2003) was more effective in hastening drying of sprayed alfalfa than the use of either compound alone (P<.Ol, L14 and P>.20; trials L13 and F34, Table 9). Mean DM for ME treated alfalfa exceeded that for K2C03 treatments in each of 3 trials (P>.20, L13, L14 and F34). The average values were 46.6 for ME and h4.52 for K2C03 while the combined treatment averaged 49.0. Main effects of K2C03 or ME and their inter— action were tested in only 2 trials (L14 and F34) that could be analyzed as factorials. The main effects of K2C03 were P<.lO and P>.20 while those for ME were somewhat more signifi- cant P<.Ol and P<.20, respectively. Tests for an interaction between ME and K2C03 as components in the spray solution were not significant for both trials (P>.20) indicating that the effects of ME and K2003 are additive rather than synergestic. 74 N.NN NN O.N N N N NN-N NNN. + co m zN. m: NN N Nz N m> N N.NN NN N.ON N NNux NNN. + as NN N mz N m> N.N N.NN NN N.NN O NooNs 2N. N NNN mmz N.N m> N.N cofluomumucH No.vm Tm m> N.N m: pommmm :Nmz ONJN N.N m> N.N ONN. N.ON NN O.NN N 22.x NNN. NOONN ”63% fin: + NooNvN 2N. m2 NN N NO.vm N.N.N m> N NNN. O.NN NN 0.0N N NN-N NNN. + m2 NN N Nz N m> N NNN. N.NN NNA O.NN O NooNN 2N. N NO.vm N m> N.N ONN. N.NN NNA O.NN O mcoz N NNN so cam: Nuun so so Nmmrnzo NON nmx\mzum coNumNuommo Ncmsummue ON NmNua mummuucoo . Umcmmz zomwm ou musom mumm cowumoNNmmd .GONMMGNQEOU ca Ho occad 0mm: mumconumu Esflnmmuom Ho mumumm Nasumz nuwz pmummua mm3 MHHMMN< amnz mcwmua mo mmusmmmz .m manna 75 Uflofl OHmHO me. + NN-N NNN. + N.ON O.NN N.N N.N NN.N NooNx 2N. m2 NN N NN\NN\N nNoN onNo NNN. + Nz N m> N N.NN O.NN O.N sax N.NN N.N NN.N NN-N NNN. ms NN N Nz N m> N N.NN O.NN O.N NNN O NN.N NOONN 2N. N Nz N.N m> N N.NN N.NN N.N 20 0.0 O NN.N NouNN 2N. N Nz N.N m> N N.NN N.NN N.N o oNN O O «:02 N NNN ON\N\ON NN-N NNN. + m C N.NN ONA ON a N N NN N NN NouNs 2N. m2 NN N NNN NN-N NNN. + Nz N m> N N.ON ONA ON so O.O O NN NooNs 2N. N mz N.N m> N N.NN ONA NN u oNN O O mcoz N ONN N.NN NNA ON ON\NN\N N.N N.N NNNNNNN.i. fix O.NN N8NM 2N. m2 NN N Nz N m> N.N N.NN NNA ON NON NzN N.N NbNNNNN.+ m: NN N ON.vN N m> N N.NN NNA ON 50 0.0 O N.N NooNN 2N. N mmz N.N.N m> N N.NN NNA ON 0 .NN O O maoz N NNN 2O saw: so so NNN use NON manna chuumum amx\mzum mN coNNmNuommo oN NmNua mHmMHu.COU UGMQE SOmmm Cu. mun-NOE mumnummap 09mm COflHMUflH AN “GmfimeB .NmscNucoo .N oNnma 6 7 .mumu cowumowNmmm mo mumawummv .20 Emum mom Mao: umm umoN Noum3 madam .mumu mcwwwoa .GONumcmmem HON N mNnma mmm .CONuwcmmem How N mNnma mom N.N.N 0§o§osnbm mz N.N m> N.N :oNuomumucH ON. m N.N m> N.N m: nommmm :Nmz ONON OHmHO me. + mz N.N m> N.N NNN. N.NN N.NN O.N N.N N.N NN-N NNN. + mOUNx vomwmm cNmz mummuucoo mOUNM 2N. m2 mm m . . Nmsomonuuo cNom ONoNo NNN. mz N m> N N N NO\NN\N + NNux NNN. Nz N.N m> N.N NNN. N.NN N.NN N.N NNN N.N N.N N.N + m2 NN N NO.vm N.N m> N NNN. N.NN N.NN N.N NNN O N.N NouNx 2N. N mmz N m> N NNN. N.NN N.NN N.N so O.O O N.N NooNN 2N. N ON.vm N.N m> N NNN. N.NN NN O.N o .NN O O mcoz N NNN 2n cam: Name 029 so NNN use NON mmumo chNumum nmxxmzum mN :oNudNuommn oN NNNue mummuucoo . ccmmz nommm on muse: mumsummz mumm cowumoaammd unmeummue .pmscflucou .m mNnma 77 Less clear results with no significant increases in mean DM content due to any treatment resulted from field trials F11, F20 and F33. Several reasons are offered for this lack of treatment effect. Forage for F11 was cut at 4:30 p.m. and a very heavy dew occurred that night. Application rates presented for trials F20 and F33 are only an estimate due to improper regulation of pump pressure. Other evidence indi- cates that treatment number 3 in F20 was effective. The result- ing hay from one half acre of sprayed and control hay was baled 3 days after cutting and core samples from these bales were 68% DM for control and 76% DM for treated hay. In an attempt to more fully explore treatment effects drying rates (DRt) for all treatments in trial L14 were com- pared over time (Figure 2) and at different WC as moisture was removed (Figure 3). Potassium carbonate increased DRt more than did ME dur- ing the first 2 hours of drying. This advantage diminished rapidly and by 8 to 12 hours postcutting DRt for KZCO3 treated alfalfa was similar to control (Figure 2). Methyl ester and ME plus KZCO treatments elevated DRt above control until 21 3 and 23 hours respectively, and then decreased below control until trial termination at 43 hours. When drying rates for the various treatments were com- pared at the same WC the rate for alfalfa treated with KZCO 3 was higher than that for ME or ME plus K2C03 treatment at a WC 78 .NmNmNmNsEm n 2m “mumpmm NmnumE u m: «mum Iconumo Efiammmuom u mooNM “Nouucoo omumouucs u DD .NNNN NMNHN. mcw>up mo muses 5N um>o mpcsomEoo mmmnu mo coaumcwneoo M NO mnmumm Nmnumfi omNmNmNsfim .mumconumo Eswmmmuom :uN3 pmummuu wuNmmam mo mmumu mcwmua .N musmflm 79 Amazon. m2: .N mssmNm 2N + N: I.N8NO_ 1!: 2N + N2 L1: NOONN Ix: 0: IMT ..1¢ov. .éco. #Doc. .éoo._ ~u- a -ao/aH/333ww ao'awa omwa 80 .HmNMNmNSEm u 2m “mumumm Nanuma u m: «mumconumo ESwamuom u mOUNM “Nouucoo pmummuucn n on .NNNN wauuv mccaomaoo mmmnu mo GONuchnEoo w No mumumm Nanume pmNmNmNsam .mumconumo Enammmuom nuN3 pmumwuu MMNMMNM NON m.o cam o.m mo mucmucoo umumz cmmzumn mmumu mcwmun .m musmNm 81 Nzuhzou mun—kc: .m muawam coo. m coo. m coo. v Dec. m coo. N coo. N o T u N N u u u N N u u . O .éow. L. too? 5 + m: . NooNx :1: 2m + N: Idr NOONO. IX: 58. 0: um: 93mm... .éoo. taco.— -u-u '80/‘8H/8318M was ‘3188 sumac 82 of 5.0 (17% DM) (Figure 3). Rate of water loss for the K2C03 treatment then declined rapidly and became similar to control at a WC of 3.0 (25% DM). Treatments containing ME maintained drying rates greater than control from WC 5.0 to 0.5 or 0.6 (63 or 672 DM). These data indicate that ME increased Drt over a longer interval and broader range of WC than did K2C03. Green and Jagger (1977) found that tissue resistance to water loss in- creased as forage WC decreased. The data from.both treated and control alfalfa presented in Figure 3 are consistent with that finding. Five trials, discussed in a following section, which examined the effect of increasing amounts of ME applied to alfalfa under field conditions contain information pertinent to the present discussion. Data from.these trials and trial F34 were used to compare the effectiveness of K2C03 solutions and K2C03, ME emulsions supplying approximately 1 ngE/kg forage in hastening drying. For each trial mean drying rates during days 1 and 2, DM content at the last weighing each day, and hours required to reach 752 DM are presented for untreated control, K2C03 and K2C03,ME treatments in Table 10. First day drying rates were greater than control in 4 out of 6 trials for K2003 treatment and in 5 out of 6 trials for ME plus K2C03 treatment. Dry matter content at the last weighing for both days 1 and 2 was also greater than control for K2003 and ME plus K2003 treatments in 5 out of 6 83 maszNmB umMN um maze Numo «cum: N.NN O.NN o.NN NNN. mNm. mN. N. m. N NNN NmA O.NN m.hm oNN. NNN. o N. o N u so UNGN NmA O.NN N.wm NNN. mNm. o o o N mNm chuusU pcoomm N.NN o.Nm o.mm mmo. NNN. NN. N. m. N NON o.mN N.Nm o.mm mmo. NmN. o N. o N u so .uNcN O.Nm m.mw c.Nm mmo. mmN. o o o N NN m o.hm o.mh o.NN muo. Nom. mN. N. Nm. N NNN m.mm O.Nm o.NN hmo. NNm. o N. o N u so .uNcN o.mm N.Nm m.mN mmo. NNN. o o o N NNm NNA O.NN o.mN mNN. moo. mN. N. m. N No.mN mmA O.Nm o.mm one. NNN. o N. o N "use .NNcN NNA N.NN N.NN boo. hum. o o o N NN m chNNso NNNNN N lzll 9:8 20 ans on muso: N awn N awn N mmo N awe 02m amoUNM mas ON NMNHB cam chuuaU :Ofixfiuumfluucmfifimfia .mpcboeaoo mmmnh mo :ONuchnEoo a Mo mumumm Nhnumz .mumconumo EnNmmmuom nuNs unmaummue chzoNNom mhmn pcoomm can umHNm gnu How mmumm waNNHQ .ON mNnma 84 .ED ammo Hmm Mao: pom H0963 madam mo mmoN .mumu ocNNHQ u umo .chuuoo um ucmmmnm umuumfi who NMNuNcN n so uNch .ucmoumm Hounds Nun n zoo .mmumoNNmmu NNNN .NNN .NNNON no .NNm .NNN .NNNON No cmmzo .mEsNo> >9 coNusNom Nahum mo N .NmNmNmN:Em n N .zmo .NNNHMNOE mumsonumo eszmmuom u S .mouan .unonB mmMHON Ammum ox Hmm m2 nacho mm ommmmumxm omNNmmm mumumm Nanuma u mx\um .mzm N.NN o.Nm N.Nm Nmo. th. NN. N. N.N m NNN N.NN m.mm O.NN moo. NNN. o N. o N u so uNcN O.NN O.NN N.Nm Nho. NNN. o o o N Nmm O.NN N.Nm N.mw mno. mmN. mN. N. O.N N NNN O.NN m.mm N.Nm who. th. o N. o N n So uNcN O.NN N.NN N.NN NNO. NNN. O O O N NNN chuuoU oncomw IWI z mx\um 29 amp ou musom N use N awn N awn N >89 mam QMOUNM mm: 0N NMNHB new mcwuuao chnmNmz NmmN um mNzo Name Ncmmz 889ng Ngg .omanucoo .ON mNnme 85 flhbhelfl). Second day drying rates are related to first day drying and dew pickup over night. Both spray treatments in- creased second day drying rates in first cutting trials (F21, F22 and F24) while rates of water loss were lower or similar to control during the second day in trials performed during the second cutting (F29, F32 and F34). This may have been due to the generally higher DM content of second cutting for- age at mowing and at the end of day 1. Overall mean drying rates for each treatment over all six trials were greater for K2C03 andME plus K2C03 treatments than for control during day 1 while during day 2 only the ME plus KZCO3 treatment had greater drying rates than control (P<.01), Table 11. These data support the results of L14 (Figure 2) which indicate that the presence of ME increased DRt for a longer period of time than did K2C03 alone. Additional investiga- tions will be necessary to determine cost effectiveness of using these chemicals in commercial farming operations. 86 Table 11. Mean Drying Rate and Dry Matter Content During First and Second Days After Treatment of Alfalfa with Potassium.Carbonate, or a Combination of Methyl Esters and Potassium.Carbonate. Mean DRfld DMdContent at Last Weighing Treatment Day 1 'Day 2 ' 'Day 1 Day 2 1. None .308 .077b 46.5 72.9 2. .2M ch03 .325 .075b 50.4 77.7 3. MEC + .2M K2C03 .329 ..oaga ‘ v 52.4 79.5 a'bSubscripts differing (P<.01). Cal 9 ME/kg forage. dValue is mean of six trials. 87 Optimum Amounts of Methyl Ester Addition In two laboratory trials ME and an emulsifier added to KZCO2 solutions and sprayed on alfalfa to supply from 1 to 4 grams ME/kg forage increased mean DM over untreated control (P<.10; L4 and P<.01 in trial L9; Table 12). Increasing amount of ME applied from 1 to 4 grams per kg produced a trend for a linear increase (P<.09) in mean DM as ME application was increased in L9 while nonsignificant increases in mean DM resulted, due to a high experimental error term, in trial L4 (P>.20). Response to increased amounts of ME appeared to max- imize between 2 and 4 grams ME/kg although a test for curvi- linearity of response was not significant (P>.20). Field trial F7, also tested the effectiveness of 1 to CO solution. The results were 2 3 similar to L4 and L9 with 2.2 gr ME/kg being more effective 4 grams ME/kg added to a K than 1.2 ngE/kg in increasing (P<.05) mean DM, while 3.4 gr ME/kg produced no further increase in mean DM (P>.20; Table 12). Mean DM content increased in a linear trend (P<.01) as ME application rate increased and no curvilinear response was detected (P>.20). Results from laboratory trials performed during the winter of 1981 testing the efficacy of KZCO3 and ME alone and in combination, discussed in the previous section, prompted us to include a treatment containing only K2C03 in all subse- quent trials examining optimum levels of ME application. 88 N.ON O.NN N.N O.N O.N NooNs sN. ms NNN N No NNN. + N NN-N NNN. + N.NN N.NN N.N O.N O.N ooNs sN. ms NN.NN N m2 0HfiflHUMDO 40 meo + NO.vo ommONo N N NN-N NNN. + Nz N m> N N NN O NN N N N N O N 00 s sN ms NN NN N No NNN. + mz N m> N N N NN-N NNN. + N2 N m> N N.NN N.NN N.N O.N O.N 00 s sN. ms NN.NN N NO.vo N.N.N.N m> N N.NN NNA N.N O O woos N No NNux NNN. + N.NN N.NN O.ON N.N N.N NooNs sN. ms NN.NN N NN-N NNN. + N.NN N.NN N.N N.N N.N NouNx sN. ms NN.N N NN-N NNN. + m Nz N > N N.NN O.NN N.NN N.N O.N NooNs sN. ms NN.N N Nz N m> N N N NN-N NNN. + omz N m> N N.NN N.NN N.NN O.N N.N 00 s sN. ms NN.N N ON.vo N.N.N.N m> N N.NN ONA N.NN O O mooz N No so ommsu-mummuuooo so cams so NNN so NON omsxmsom N ooNNoNuommo pomsummoa oN NmNus nommm on muoom mama GONumoNNme .MHNOHUNNHOM mumNNOQHMU gflmmmuom CH mhmfimm N>numz mo mu::0&¢ maNmmmuocN nuN3 MNNMMNa mo usufiumwue Hmumm mnNhuo mo aungmHSmmmz .NN mNnma N.NN O.NN O.N NN. N.N NNux NNN. + NN\N\N NooNs sN. ms NN N a o O.NN O.NN O.N o s N NN NN. N.N NN-N NNN. + as N m> N NNN NooNs sN. ms NN N mz N.N m> N N.NN N.NN O.N go 0.0 O N.N NooNs sN. N as N.N.N m> N N.NN O.NN 0.0 o .NN O O oooz N NNN N.NN N.NN O.N NN. N.N NN-N NNN. + NooNs sN. ms NN N N.ON N.NN O.N NN. N.N NN-N NNN. + MN\NN\N NouNs sN. ms NN N m> . as N N N.NN O.NN O.N o N O NN NN. N.N NN-N NNN. + mz N m> N NNN NouNs sN. ms NN N Nz N.N.N m> N N.NN O.NN O.N So O.O O N.N NooNs sN. N wONJo N.N.N.N m> N N.NN O.NN O.N o .NN O O oooz N NN.N N.NN N.NN N N.N N «o NNm. .NN Ens NNN. + o s s . as N . N.NN N.NN N.N . N.N N <0 NNN. + Ens NNN. + NO vo omooNo nos N N NooNs sN. ms NON N ms N 3 N N.NN N.NN N.N NNN N.N N No NNN. + 23x NNN. + NO.vo N m> N so O NooNs sN. ms NN N NO.vo N.N.N m> N O.NN NNA N.N o °NN O O oooz N No 2o :mmzlnmummuucoo so so mm». 29 NoN mmumo chuNmum nox\mzum UN GONumNuommo usmfiumwue 0N NMNHB com: snommm ou musom cam mumnummz mumm coNuMONNmm< ooooNNooo .NN oNooa N.NN O.NN N.N N.N N N NNNux NNN. + m2 oNoNoomoo on s sN ms NN I buns NNN. + NNero HmoONo O.NN N.NN N.N oNN\N\N N. N NooNs sN. ms NN mz N m> N N.NN NNA O.N o N N NN N. N N NNNnx NNN. + Nz N m> N NNN oo s sN. ms NN nNu.ON.vo N.N.N m> N N.NN NNA N.NN so 0.0 O N NooNN sN. as N m> N O.NN NNA O.NN u .NN O O oooz NNN N.NN O.NN O.N O. N.N NNux NNN. + oNN\N\N NooNs sN. ms NN ON vo N m> N N.NN O.NN N.N o s N NN N. N.N NN-N NNN. + NO.vo N m> N NON NooNs sN. ms NN NO.vo N m> N N.NN O.NN O.NN so O.O O N.N NOoNs sN. NO.vo N.N.N m> N N.NN O.NN O.NN o .NN O O mooz NNo so cmmzllmpmmuucou so so wa. so NON omumo chuNmpm Imox\mzum w coNumNnommo ucmsummue DH NMNNB com: snommm ou mason cam mumcumm3 mumm QONNMONN d .omooNuooo .NN oNome 91 .mcowumamamxm MOM m magma mmm .mmm cam mmm .Nmm .mq .NA mmumowammu N mo can .Nmm can Hmm .mmumowammu m mo cams n.m.N N .mcowumcmmem How A magma mmmm.o.n.m N.NN NN N.N O.N N.N «o NNN. + NNnx NNN. + NouNx 2N. m2 NN N Nz ONNNNNNOO N.NN NN O.N O.N N.N No NNN. + Nz ummcflq N NNNux NNN. + OH.vm N m> N HN\N\N oo N 2N m: NN N N.NN NN N.N . N. N.N No NN. + m> a N2 N N n x N N N Nnnnx NNN. + NO.vm N m> H NNN 00 x 2N. m: NN N ago Nz N.N.N m> N wN.NN NN N.N so O.O O N.N NooNN 2N. N N:N NO.vm N.N.N.N m> N N.NN NNA O.N o oNN O O Houucoo N NNN 20 cmmznumummuucoo an an NNN 29 NON manna mcwuumum ammxmzum N coNumNuomma ucmeumoua nH HmNua cmmz anommm on muse: can mumzummz wwwm cowumoaawmm .cwaQNMGOU .NH manna 92 The addition of small amounts of emulsified ME to K2CO3 solutions supplying 0.16 to 0.64 gr ME/kg did not increase mean DM above treatment with KZCO3 alone in trial F24 or above control in F22 (P>.20, Table 12). On the other hand in trial F21 where K2CO3 alone did not increase (P>.20) drying, addition of 0.2 or 0.9 gr ME/kg further increased (P<.01) mean DM (Table 12). Since ME K2C03 emulsions supplying less than 0.5 gr ME/kg forage appeared to have more limited effectiveness above the use of a K2C03 solution, trials F29 and F32 were designed to test ME applications of 0.5 to 3.0 gr ME/kg. Potassium carbonate alone increased (P<.01) mean DM in F32 but was not effective in F29 (P>.20, Table 12). Addition of ME hastened drying more effectively than did KZCO alone (43.3<45.7, 48.0, and 47.9 in 3 F29 at P<.Ol), while only a non-significant increase was noted in F32 (57.l<57.5, and 59.7 at P>.20). Application of 0.4 (F29) or 0.5 (F32) gr ME/kg produced a small increase in mean DM above K2C03 treatment in F29 but had no effect in F32. Increasing application to 0.8 (F29) or 1.0 (F32) gr ME/kg increased mean DM (48.0>45.7 and 59.7>57.5 at P>920 in trials F29 and F32 respectively) and decreased hours to 75% DM, but further increases to 2.0 (F32) or 3.6 (F29) gr ME/kg slightly depressed mean DM and increased hours to 75% DM. Increasing application of ME tended to increase mean DM in a linear trend (P= .11) in F29 but not in F32 (P>.20). 93 Curvilinear responses (P>.20) were not significant in either trial. The minimum effective dose of ME when combined with K2C03 and an EM, at solution application rates of l to 4% ap- pears to be approximately 0.5 gr ME/kg, while the most effective rate is between 1 and 3 grams ME/kg. A trend towards a linear response to increased ME application was detected in 3 trials while a curvilinear response was not significant. This find- ing may be due to having only one treatment in each trial sup- plying more than 2 or 3 gr ME/kg. Maximizing Coverage by Changes in Liguid Application Rate and Spray Pump Pressure In two trials application rates of .2M KZCO solutions 3 were increased from 2.3 to 3.3% (F26) or from 2.8 to 4.4% (F34), with no attempt being made to keep the weight of K2CO applied 3 per kg forage constant. In both trials K2C03 at either rate increased mean DM (P<.01 in F26, Table 8, and P<.20 in trial F34, Table 9) while no differences (P>.20) in mean DM content were detected between the low and high application rates. These results are consistent with the work of Tullberg and Minson (1978) who also found no significant difference in drying of alfalfa due to increasing the application rate of .2M K CO 2 3 to 3.7% of wet forage weight). from 200 to 875 liter per hectare (approximately 0.8 94 When ME plus an EM was added to a K2C03 solution to sup- ply approximately 1 gram (L3) or 2 grams (L5) ME/kg forage in spray volumes ranging from 1 up to 4% all treatments increased mean DM above that of untreated control (P<.01; Table 13). In- creasing solution application rates from 0.87 to 1.3% (L3) or from 1.2 to 1.8% (L5) while maintaining a nearly constant ap- plication of active ingredients by changing concentrations, pro- duced no increase in drying (treatments 3 vs 4 in trials L3 and L5; Table 13). Further increases in the volume of liquid ap- plied from 1.3 to 3.0% or from 1.8 to 3.9% did produce a large but non-significant increase (P>.20) in mean DM (47.5>43.8 in L3 and 51.6>4S.9 in trial L5; Table 13). In three field trials where 1.2 grams (F35) or 2 grams (F15 and F18) MB per kg forage were applied at liquid applica- tion rates of 1 to 4%, all treatments increased mean DM over untreated control (P<.01; Table 13). Increasing liquid appli- cation rate from 1 to 2% produced a small non-significant in- crease in mean DM while increasing solution application rate from 1.5 to 3.0% (F35) or from 2 to 4% (L15 and L18) increased mean DM (P<.05). The application of 9.4% distilled water did not hasten drying (Weighart et a1., 1980), thus increased mean DM from a larger volume of liquid is most likely due to a more complete or more even coverage of the sprayed chemicals on the forage. For practical field use low spray volumes of 15 to 20 gallons per acre would be desirable for ease of operations and 95 minimization of labor costs. A typical yield of 1.5 tons DM per acre during second cutting would require 18 gallons solu- tion per acre to attain a 1% application rate of liquid to fresh forage. Data from F18 and F15 (Table 13) indicate that an application rate of 2% (36 gallons/acre) supplying 2 gr ME/kg decreased time to 40% DM from 36 to 4 hours (F18) and from 24 to 4 hours in F15, while increasing liquid application further to 72 gallons per acre (GPA) (4%) reduced interval to 40% DM by another 1 to 2 hours in both trials. In trial F35 hours to 75% DM were 26 for control and 7 for alfalfa treated with a solution supplying 1.2 gr ME/kg at a 15 GPA (1.5%) liquid application rate. Doubling application rate to 30 GPA (3%) decreased interval to 75% DM to 6 hours. In three field trials spray treatments of 15 or 36 gal- lons of liquid per acre increased mean DM content and decreased interval to 40 or 75% DM by an average of 24 hours compared to untreated control, while further reductions of 1 to 2 hours were obtained by increasing rate of liquid application to 30 or 70 GPA. These data indicate that while satisfactory increases in drying of cut alfalfa can be obtained with liquid applica- tion rates of 1 to 2%, larger volumes of water can be used to obtain a greater effect from the same amount of applied chemi- cals. Experiments designed to explore other possible methods of liquid application which could maximize coverage with smaller volumes of water appeared warranted. 96 Increasing spray pump pressure decreases mean droplet size (Spray System Co., 1977) this could increase distribution of the spray material but could also increase loss of spray due to drift. In two trials increasing spray pump pressures from 30 to 50 Psi (F16) or to 60 Psi (F18) at liquid application rates of 2 or 3% produced no increase in mean DM (P>.20; Table 13). Visual examination of spray patterns using solution contain- ing floricine dye showed similar extent of coverage for both pressures with a finer droplet size resulting from the higher pressure in F16 while coverage of leaves and stems was superior for the lower pressure in L18. These trials indicate that spray pressures of 30 Psi are sufficient when flat fan Tee jet nozzle tips are used. Further research on type and location of nozzles and spray bars is desirable. m.bN N.N hblx mm. + NooNN sN. ms NON N . m.mN m.mN m.m N.N N.N hhlx NN. + N2 N N m> N NooNN 2N. ms NON N m> Nz N N N.NN N.NN N.N NN.N N.N N N Nhux NN. + m2 m m> N 00 x Em. m2 mm N No. N.N.m m> N N.NN Nm N.ON o o Nouucoo N ma N.NN O.NN N.N O.N hm. m N hhlx mm. + m2 N.N m> N 00 M 2m m2 NNN N N.NN O.NN N.N m. N.N hhnx NN. + Nz N m> N NooNs 2N. ms NN N Nz N N> N N.NN N.NN N.N N. O.N NN-N NN. + mmz N m> N NooNx 2N. m: NN N No. m N.N.N m> N 0.5m o.om O.NN o o 0:02 N mN so :mmzuumummuucoo ago :9 2n NNNNDEQ NON manna chuumum nuxNMSHN N coNumNuommn oN NmNus u Ncouummcom undo: snomwm on mason , mumnummz wwwm coNumowNmmfl uswfiummna .musm Immum mean amumm Ho chvHN omNNmmd mo mussoad :N momsmnu >n poocwstsH mm mwNmNNé mo msflhun .MN mNQMB 98 NNN. N.NN O.NNA O.N N NN N NN NNux NN. + ONNNNR oo 2N ms NON N NNN. N.NN O.NNA O.N . N N NN-N NN. + :9. N NN .N ooNvN 2N. ms NON N Nz N m> N NNN Nana NON. O.NN O.NNA O.N N NN NNux NNN. + mammm NO.XN N.N m> N .5 0.0 NooNx sN. ms NN N 9.35 NO.vm N.N.N m> N NNN. O.NN O.NNA N.NN 0 .ON O O mcoz N NNN N.NN NNA N N Nmo N NN-N NN. + ON\N\N o x 2N ms NON N . N.NN NNA N . N N NNux NN. + NO vm N m> N sax N NN NooNM 2N. m2 NON N Nz N N> N N.NN NNA N NNN N N N Npsux NNN. + NO.vm N m> N 50 O oo s sN. ms NN N NO.vm N.N.N m> N N.NN NNA NN o .NN O O mcoz N NNN N.NN O.N O.N N.N N.N No NNN. + Nhnx NNN. + NooNN 2N. ms NN N N.NN O.NN O.N N. N.N <0 NNN. + NN\ON\N N Nhhix NNN. + NO.vm N m> N sax N.N 00 x 2N ms NN N . N.NN O.N N.O N.N O.N No NNN. + NO vm N m> N NNN NNnx NNN. + mz N m> N so 0.0 NooNx sN. ms NN N NO.vm N.N m> N N.NN O.NN O.N o .NN O O mcoz N NNN so cNNSuumummNucoo was an sa NNN 02a NON mwumo maNuumum amx\msum N coNumNuommo oN NwNus u Nsouummcom pmsmmz snommm on musom mumnummz mumm GONNMOWMMMfl usmfiumoua .UmscNusoo .MN MNQMB "\(luiHI‘I'I‘ 99 .Nmm om manna 950 wmummx .Nmm om ousmmgm 95m mmummn . Nmm om waned 9.5m wmumma .gflmcmvaa “Sm m 3nt mommdfi . mSNuQBNQNw How. N mNNNmB mom mNUsnum ON\N\N N.ON ONA O.N . N.N N.N NN.N NNN. + fixNNN N N8NNNNN.N:NN N Nz N N> N N.NN ONA N.N NON N.N NN.N N Nhyx NNN. + .5 0.0 . 8N: 2N. N2 NN N NO.vm N.N m> N N.NN ONA NN o .NN O O mcoz N NNN ON\ON\N NNN. N.NN NNA . sax O.NN . u N a H3 m> . . A l I I . N2 N N NNN N NN NN NON N nun ch N.vm N.N m>.N NNN. O.NN O.NN . .26 NN. - u N JNHNNN NOJN N.N.N m> N NNN. N.NN NR .. o .NN n u N NN.N so unmannmummuucoo was so so Nwauso NON mmumo chuuNuN nvx\m2um N coNudNuommo aN NNNus u Hdouummcom Cmdmmz finommm OH mHNNOE «HON—#003 Guam COflHMOHHMNaIN .NmscNunoo .NN oNnma 100 Chemical Treatment of Different ForageSpecies and Methods of Expressing and Evaluating Treatment Effects Interpretation ofresults from drying trials with dif- ferent forage species may be complicated by differences in initial moisture content or differential responses to chemi- cal treatment. Several methods were used to express differences in drying,due to chemical treatment, within and between three legume species in trial L17. Discussion of the data and valid- ity of the methods of expression follow. One way analysis of variance for the repeat measure split plot showed that spray_solutions of ME, K2003 and an emulsifier (EM) increased mean DM of red clover (RC) (P<.05), alfalfa (Alf), and birdsfoot trefoil (Bft) (P<.01), above re- spective controls for each species, L17, Table 14. Initial DM contents of the three legumes were 29, 28, and 20% for RC, Alf and Bft, respectively (Table 14). Time required for sprayed forage to attain 40% DM was reduced by 2.5, 4.0 and 7.0 hours for RC, Alf and Bft compared to respective controls. Although these values can give a good indication of differences in relative drying rates between treated and untreated forage within species, they have limited meaning for comparisons between species which have different initial DM content. In this case Bft initially contained much more water per gram DM than did RC or Alf and thus would be expected to require a longer interval to reach a specified DMZ. 101 .NNommyH uoommpuNmu ummx .NHGdNN NNO. NNN. O.NN O.NN NNA N.N NN O O Numész N NNN NN-NN mm NN-N mm NN- ON SE B- N 8% N fin 8% swam: NH 58% Ngfiz anmmanONE ENE Mb NB NMNfichN NzuN MmeM 3 N95. 3.0.828 NNEBaN fig 8 88oz 3% SNNSNNMNN .Aummv NNommuH uoowmanm paw NMN0No pom cmummua NNNNONEmno cam Nouucoo How mumumamumm wsNhun mo :ONudNuonn .NN mNan 102 Another method of expressing speed of moisture removal in this trial is to calculate the time interval between 30 and 602 DM (Table 14), this eliminates the differential effect of initial DM content. Sprayed Alf and Bft required only 5.75 and 6.0 hours to increase from 30 to 602 DM compared to 16.0 and 17.0 hours for their respective untreated controls. Sprayed and unsprayed RC needed 13.5 and 18.0 hours to increase in DM content from 30 to 602. Thus spray treatment decreased this time interval to 352 of control for Alf and Bft but only to 752 of the control value for RC. This method of expression differentiates between species within a given range of DM con- tent but it does not provide information about species differ- ences during the early and final stages of drying. When trial L17 was analyzed as a factorial a three-way interaction involving species, chemical or no chemical treatment and weighing period was detected (P<.01). Untreated material of each species exhibited a nearly linear increase in DM content over the entire 23 hour trial. However non-parallel trends in the drying of sprayed Alf, Bft and RC were observed (Figure 4). Drying curves for sprayed Alf and Bft were non-linear, increasing much more rapidly in DM content during the first 10 hours than from 10 to 23 hours post cutting. In contrast sprayed RC had a much less pronounced difference between the first 10 and last 13 hours of drying (Figure 4). Large treatment differences were established during the first 10 hours, therefore mean drying rates, determined as loss 103 .NO NNN. + 2-x NNN. + NOONN 2N. + m2 NN No 8338 m nuNB pohmudm u m NNNowmuu DoommpuNn n uwm “NMNMMNN u MN< Num>oNo can H Um .NNNN NNNHHV wGNuuso um unmaummuu NNONano usonuw3 Ho nuN3 wsNNHp mo mHSoL mm chHap NmNomdm masme mmsnu mo usmuaoo umuumfi hum .N muszm .N ouszm Amaze—.2 m2: ummIm I‘JMIIIEIIEJB 104 z-II-IJ -écn 105 of grams water per hour per gram DM, were compared for this period to evaluate species differences and response of each species to chemical treatment. Mean drying rates (Drt) during the first 10 hours were similar for control RC and Alf but were less than for control Bft (0.17, 0.l9<0.21 at P<.01; Table 14). Spray treatment increased drying rates above re- spective controls for each species during the first 10 hours (P<.01), on the other hand, from 10 to 23 hours Drt for treated forages was less than for their respective controls (P>.20 for Alf and RC and P<.05 for Bft). Drying rates for each species during the first 10 hours after spray treatment ranked from the slowest to the most rapid were RC (.205)0No won I om .NNNN NNNHHV ucmfiummuu NmoNamfio usosuNs Ho SuNs meommm masme mounu How m.o cam m.m mo mucmucoo Hmumz smo3uon mmumu chhun .m muszm 107 .NZMNZQQ mum—kc: ooo.m . oow.w cow.N . cow.m u wmIm awn w N.20) L12, L26, L32, and L34 (Table 15). In Trial L12 the addition of 12 crop oil concentrate (COC( to a ME K2C03, X-77 solution tended to increase (P<.10) 110 .NO NNN. + 2-x NNN. + NONNN 2N. + N: NN No 8338 LDNB cmhmumm n m NNNommuu uoommwuNb u umm “NMNNMNN u om u MN< Num>oNo con .ANNN NNNHHV wsNhup mo mnson mm wsNusc ucmaumouu NNUNano DDOSuNs No nuNB mmNomam oasme mounu cw chcNmamu Hmum3 NNNDNSN mo ammucmoumm .o muszm Pace/If o’r'InH-za) Naued’semainznd 100 ‘8 3O 20 IO- 111 ‘7 A/ oi §I6131R121313f17j429 Figure 6. TIME (HOURS) 112 mean DM of vegetative BG above control while in trial L26 a BC, 0G mixture treated with CDC alone or in combination with the three component solution had mean DM.and Drt values similar to control (P>.20). Brome grass at seed stage (L32) and at a vegetative stage of maturity (L34) had greater initial DM contents than did alfalfa at 20% bloom (L32) or alfalfa at 102 bloom from the same field in trial L34 (39>20, and 23>21Z respectively; Table 15). Hours to reach 752 DM were similar for both treated and untreated mature BG and treated Alf (48 hours in L32; Table 15) while untreated alfalfa had reached only 60% DM in 48 hours of drying. Intervals for control BG and sprayed BG and Alf to increase from 40 to 602 DM were also similar, 11.0, 10.5 and 12.5 hours respectively while unsprayed Alf required 16.0 hours. In trial L34 both treated and control BG reached 402 DM one hour before treated Alf and 2 hours before control Alf. Brome grass treatments retained this advantage and reached 752 BM in 33 to 36 hours while treated Alf required 44 hours and con- trol Alf did not reach this DM content in 45 hours. Interval between 40 and 602 was 18.5 and 16.5 hours for control and sprayed BG and 21.0 and 13.0 hours for control and sprayed Alf respectively. Mean Drt was greater (P<.01) for sprayed and unsprayed Alf than for treated or untreated BG (F32 and F34; Table 15). Faster rates of water loss but longer intervals to 40 and 75% DM for Alf are due to the lower initial DM content of Alf come pared to BC used in these trials. 113 ONN. N.NN N.NN N.O N N 583 NON NNN 58889 N Nz ON.vN N .3 N NNN. N.NN NNN O.NN NNON O O .88 NON NNN .82 N Nz Nz N s, N ONO. N.NN O.NN N.N N N ON 93889 58889 N NO.vN NON N.NN>N.N OON. N.NN N.NN N.N NNN O O ON 8388.8 .962 N NNN OON. N.NN NN N.NN N N a8NN NON NNN £2.88. N 8.8 2.1 N g N NNO. N.NN NNA O.NN NON O O soONN NON «N... .952 N N2 N2 N g N NNO. N.ON NN O N N ON NEON: 58889 N 8.1 8.8 N.N N> N.N NNO. N.NN NN O NON O O ON 885% 682 N NN.N NNN. N.NN ONA O.NN O N 8 + ON 9388.5 8 NN N 8 + on o>Nu3mmO> N2 N2 N 8 N NNN. N.NN ONA O.NN N N 8 NN + 58.4.88. N Nz Nz N 9 N NNN. N.NN ONA N.NN N N 8 + ON 93888 £888. N N2 N2 N 8 N NNN. N.NN ONA N.NN NN.NN O O 8 + ON 93888 82 N NN.N ON 93883, OON. N.NN N.NN N.N N N No8 NN + £88.89 N Nz ON.vN N g N NON. N.NN N.NN N.N N N ON 258%.; £88.89 N Nz NNz N 9,. N NNN. N.NN N.NN N.N NNN O O ON 93388 852 N NN.N to 82 E 8% mtg E E 8825 N8 ON Nata. Nfimmfifiso '11 I 5 mm ENOSNNmmN NE 88m 8 was: NNNNNNON unfixruungusmfiaayH 41' .usoEummuH NNONEOSU ou msoNuNpcoo usoummmwa Hops: s3ouu Ho NONuwusumz NaOHOMMNQ um NMN m NNN. N.NN ON 3 N93 0 o m? 3%me H0580 m Nodm SJm N m> H NNN. 93 NNA N.N H N E vamwmnvmummfl. N WHEN—m NNN . o . mN NNA mm NN. N.N o o a 3mg Nouucoo H 34 m3. N.NN m? 9: H N m? gnu £8389 N Ho.vm Ho.vm N N5 m mNH. mNm MMA N.NN NN.NH . o o . H2 magmhu Houucoo m mo.vm 86m N m> N m3. mém NN N6 H N H? EOE 58339 N 3mm 30. N.NN mmA N.NN uméN o o m2 336 H0380 N .34 ed :82 2N 8% N95 E E NNN E NON E anNNzNN N mmNuoNN NE E Nata mummuuNNoo twang £03m ou mg magma: Oudm 838.“? 833N039 mam—Emma“. .2350 .3 mafia? 115 Because of these differences in initial DM content drying rates at a given WC can provide a more meaningful com- parison of actual species differences. Between WC 3.0 (25% DM) and 0.5 (6.72 DM) BG generally had greater drying rates than did untreated Alf (L32 and L34, Table 16). Spray treatment of Alf increased drying rates at any given WC between 3.0 and 0.5 resulting in values similar to those for BC (Table 16). Chemical treatment of BC or BG OG mixtures at two ma- turities did not consistently increase mean DM or Drt above controls, while treatment of alfalfa was effective in increas- ing drying at both maturities. Lack of effectiveness for chem- ical treatment of the two grasses studied may be due to differ- ences in the cuticular wax structure and composition of alfalfa and the grasses. At a given WC, BG dried more rapidly than did untreated alfalfa while sprayed Alf dried at a rate similar to BC. These data suggest that spray treatment of alfalfa, grass mixtures would tend to equalize drying rates of the two species and pro- vide a more uniformly dried product for baling. In two trials spraying alfalfa grown under "greenhouse" or field conditions with a solution of ME, K2C03 and an emulsi- fier, increased mean DM and generally increased drying rates above respective untreated controls (P<.05 in Lll and L16; Table 15). Initial DM content of fall grown field and "green- house" grown alfalfas were 26.5 and 18.22 respectively while spring grown field and "greenhouse" alfalfas were 14.2 and 16.32 DM (Table 15). 116 .omnonamonu n s .No NNN. + 2-x NNN. + NOONN zN. N: NN 5N3 ONNNNNN u .2m mawuw\nmum3.mamuw ucoucoo nmumz n 03w .zn Emum\un\umum3 mawnw mo mmoN n oumu wcfihun .aoNudNHomon usuaumouu How NH manmfi mom“ 0 mo mo. mmo. ON. NN. mm. . NN< mo:m N u no. ca. NN. ma. : mH< :0 n no. mmo. ma. n u .. m2 395% N mo. co. ca. u u u MH< pamah H NNN mNo. ON. NN. om. Nn. . MN< maum N mo. ca. ma. ma. NN. n ma¢ Ono m mac. mNo. ca. NN. Hm. cm. a gmfihum N u a mmo. NH. NN. om. ma< pamwm a wad mo. mo. NH. mm. : I maNu um mwamma< paw mmmuw vumnouo .mmmuu oaoum mo moumm wfiwhun .oa manna 117 To eliminate initial DM as a complication in interpre- tation of the data Drt at given WC were calculated and are presented in Table 16. Drying rates were similar for sprayed material from either environment from a WC of 2.0 to 0.5 (L11) and from 4.0 to 0.5 (L16). Control alfalfa from.both environ- ments dried at similar rates between WC 2.0 and 0.5 in Lll while in L16 control field material dried at a much slower rate than untreated "greenhouse" alfalfa from a WC of 4.0 to 2.0 (Table 16). Faster drying of control greenhouse alfalfa than field grown alfalfa in L16 may have been due to its higher leaf to stem ratio and smaller stem length (Table 17), while equali- zation of Drt at a given WC by spray treatment may indicate that differences in epicuticular wax layers may have a greater effect on rate of moisture removal than differences in plant morphology. Low temperature, low relative humidity and long photo period have all been shown to increase epicuticular wax pro- duction (Wilkinson and Kasperbauer, 1980, and Pallard and Kozlowski, 1980). None of these environmental factors were well standardized or monitored in these trials making inter- pretation of the results highly speculative. Data from these trials do indicate that the use of field or greenhouse grown alfalfa for laboratory drying trials can result in similar responses to chemical treatment, validating the use of greenhouse grown alfalfa as a model for screening chemicals to hasten drying. 118 N.ON N.NN N.N.N N N.N NON 80 ON NNNNNNN on NNNNNN masonammNO N.N O.NN N.NN N N.O N N.O NON ac OO NNNNNNN on NNNNN\N NusouO ONNNN N.N ONN - - - - NON - NNNNNNON ou NNNNNN masoncmmNO N.N - - - - maoz - NNNNNNON ou NNNNNNN NusouO NNmNN N.N NNN swam mama mmmmm.zb Nwmmm £moum Boon nuwcmq Scum usoacoua>cm nuBoHo 9H HQNHH NNN NmNuNcN ONNNN amum ON NmmN N wcoauwvcoo waowm can omfiofifimmuo Hows: :3ouw mmamm~< mo moaumwuouomnmso .NN manma 119 Further trials examining drying of forages grown and dried under different, controlled environmental conditions could help explain differences in drying time to baling for the first and subsequent cuttings of alfalfa during the grow- ing season, and deserves further study. Drying of Alfalfa in Swaths or Windrows Under Variable Field Weather Conditions In two trials alfalfa drying in 2.2 meter-wide swaths attained greater mean DM content than did material in 1.0 meter- wide windrows (P<.05; in F3) and (P<.01 in F9; Table 18). Spray treatment of swaths or windrows failed to increase mean DM above respective untreated controls in both trials (P>.20). This lack of treatment effectiveness may have been due to low solution application rates in F3 and to light rain showers 4 hours post cutting in F9. Swathed alfalfa had reached 32% DM at the last weighing before rain while windrows were only 26% DM in F9. A total of .68 cm rain fell during the afternoon and first night de- creasing DM content of both swaths and windrows to 252. Dry- ing conditions were favorable the second day and swathed treat- ments reached 55 to 57% Dlehile windrows reached only 45% DM. During the second night the drier swathed forage picked up more moisture from dew than did windrows reducing the DM content to 47 and 442 respectively. Final DM content of swaths were greater than for windrows (70 to 752 65 to 66% DM), at 49 hours post cutting. Drying rates for swaths were consistently greater .mow3 Hmuwe O.N mzouoawsm .mnN3 unmade m.N ou O.N sum3mu .coflumammem HON N manna mom .m .mwumowammn m mo cams: .QONumcmmeo Ham N mNnme mown m.o.n.m O.NN NNA NN N N souoch No NNN. + m Nhhnx NNN. + NNN N.NN oo N 2N N2 NN N N.NN NN NN NNN N N numzm No NNN. + NNNuN NNN. + Oz N m> N No NN.O Noo N NN. m2 NN N Nz N m> N N.NN NNA NN o NNN O O soNcaNz ooummuucs N oNO.vN N.N m> N.N N.NN NNA NN NNNONNN O O sumam omummuuco N NN 3 1 O.NN NNA NN N N sounchuNNuN NN.+ NooNN NN. N2 NON N N.ON NN ON N N numsmuNNuN NN.+ Noo N NN. N: NON N N.NN NNA ON N N NMNSNuNNuN NNN. + mz N.N m> N No 0.0 ooNN NN. N2 NON N Nz N m> N N.NN NNA NN o oNN O O mzoucha cmummuuaa N NO.vN N.N m> N.N N.NN NN ON NNNNN\N O O unumzm Omummuuao N NN Na cmmznumummuucoo so can NNN No NON mumfimmz N QONNNNNN. N SNNNNNNBON .Emfimmua ON NNNNN. Odom: snomom ou musom noumo mnwuumum mumm coaumoNmem .maw3oz Hmuwd 30HGNN3 no spasm m :N puma max puns NNNMNNN Umhmummco new owmmumm >NNMONEm£U Hem mcwmun Ho mmuammmz .NN manna 121 than for windrows on each day and mean rates of water loss for the entire trial were significantly greater for swaths (P<.Ol in F9; Table 19). These results support the findings of Thierstein (1966), Barrington and Bruhn (1970) and Dale (1979) who reported that drying of windrowed forages was slower than for swathed mater- ial. Less exposed surface area for interception of solar radi- ation and increases in relative humidity within bulked forage appear to be two important factors limiting plant drying in windrows. The generally lower moisture content and larger ex- posed surface area of swaths may explain why swaths absorbed larger amounts of dew or rain. In another trial (F18) initial drying of swaths treated CO emulsions and untreated control swaths was com- 2 3 pared to redrying of the same forage after .25 cm rain (Table with ME, K 13). Rain at 41 hours post cutting reduced the DM content of treated swaths from an average of 53% down to 46% and reduced DM of untreated material from 45 to 37%. Treated swaths main- tained a DM content greater than control throughout the trial and at trial termination (74 hours post cutting) the treated swaths ranged from 68 to 78% DM compared to 58% for the untreated oam:nl. Drying rates were much greater for treated swaths during the first day of drying but decreased below rates for control swaths the second day (Table 19) due to the much higher DM con- tent of the treated material. During the second night .25 cm rain fell. Drying rates the third day were again greater for treated swaths (averaging .l72>.164 for treated and control 122 .ANo.vm. NMMMNn NMNNN m CNNNNS mumflnomnsm unmuommfio suNz mnmoz .Ummmumm n m .ucmfimunmmmfi mo mOONme Aoav Ho .mmvw um mmvmowammu m mo cows .usmwc m50N>mHm on» :Nmn Ev mN. umumm mmumu mcwwuo .NNMN so we. Hmumm mmumu onwhuo .mcoNumNnommn ucoaumona NON NH mNnt mom N.N u 0'00) .Bonchz moNz Hmume O.N no num3m moflz HmuoE N.N uchhuv madman an: no musuonuumm NNmN. UNNN. moa. Nom. N num3mlm NNON. oohN. ONN. cam. m num3mum NmNN. UNNN. NNN. awn. N num3mlmm thN. cNmN. NNN. mmm. N spasm NNN NNNN. NN. onN. me. N 30N©NN3Im NONN. mmN. onN. mwm. N 30N©GNB xth. NNN. onN. NNN. m numzmlmm xNoN. NNN. ONNN. Now. H num3m mm llllllllll so Hm\usxnmum3 Em aw,omcmnolunlnlnlul onme man UMMAB awn ccoomm awn umnwm QQH monsuosuum NMNNB mmumm mnNMNQ .mNMNNa onNm 039 :N :Nmm can 300 Houmfl 0cm mnemmm mwammam mo mmumm mcawua .mH manna 123 swaths respectively) which suggests that the larger amount of moisture picked up by treated swaths was more easily removed than was the original intracellular water still contained in the untreated control. Treatment differences established during the early stages of drying, following chemical treatment, were maintained during and after light rains in the latter stages of drying. The lack of an increase in drying rates from chemical treat- ment in F9, where rain occurred before large treatment differ- ences were established, may have been due to washing away or dilution of the chemicals and reversal of treatment effects similar to those reported for treated and subsequently washed grapes Grncorevic (1963). This idea would suggest that the treatment of alfalfa with ME, KZCO3 emulsions shortly before a heavy dew or when rain is likely to fall that same day, should not be recommended. Apparent Respiration Losses During Field Drying Respiration loss during drying was considered as the difference in the initial amount of DM on a screen and the amount of DM present at the final weighing during a trial. Values for 10 untreated control forages ranged from a loss of 22.42 to an increase of 3.2%. Figures for material treated with ME and K2003 ranged from losses of 14.3 to increases of 14.92 (Table 20). 124 NN.N - N.NN O.NN NaNNo Npmm: Omummus N O.NN- N.NN O.NN OaNNo unmNN NNNNNNNN N N.NN- N.ON O.NN NaNNo NN>NNN maoz N N.NN- N.NN O.ON NaNNo OuNNNN mcoz N NNN N.N+ N.NN N.N NN-N NNN. + NOONN 2N. N2 NON N N.N- N.NN N.O ocoz N ONN NN.N+ O.NN O.NN sONNaNs Noummue N NN. - N.NN O.NN osouuch maoz N 0.0 N.NN O.NN Numzm - NNNNNNNN N NN.N+ N.NN O.NN NNNmsm - maoz N NNN N.N+ N.NN N.N NN-N NNN. + NOONN NN. N2 NNN N N.O+ N.ON O.N NN-N NNN. + NOONN 2N. N2 NON N N.N+ N.NN N.N NN-N NNN. + NOONN 2N. N2 NN N N.O- O.NN N.NN mcoz N NN NNNNNNNN EONN 2N 2O 2N NOO NONNNNNONNN Namaummue NN NNNNN NH mwcmso N ammz ou munom .NHNNNH vHon uawwm aw wcwhun wawnsn mommoq cowumuwmmom ucoummm< .ON venue 125 N.N - N.NN O.N NN-N NNN. + NOONN 2N. N2 NN N N.N - N.NN O.N N2 NN N N.N - N.ON 0.0 NOONN 2N. N N.O - N.ON O.N NOONN 2N. N N.NN- O.NN N.NN «coz N NNN N.NN- N.NN N.NN NN-N NNN. + NOONN 2N. N2 NN N N.N - N.NN N.NN NO NN. + NN-N NN. + NOONN 2N. N ON. - O.NN O.NN NOONN 2N. N N.N - N.NN O.NN Nomz 2N. + NOONN 2N. N N.N - O.NN O.NN maoz N NNN N.NN- N.NN O.NN NN-N NNN. + NOONN 2N. N2 NN N N.N - N.NN N.NN NOONN 2N. N O.ON- N.NN O.NN NN-N NNN. + NOONN 2N. N N.N - N.NN O.NN NOONN 2N. N N.N - N.NN O.NN mcoz N NNN MHGHUHd—H EOHW zn SQ SQ NCO COHUQHHUQQQ UGOBUNUHH. QH HGHHH. NNN mwcmnu N cam: on N.NNNom .NmncNNaou .ON NNNNN 126 -NNOON m No N How chNNn chunv Houuwz.hun mo Auv mmoH No A+V :wa owmucoouom cam: .NN-N NNN. + NOONN 2N. N2 NNN .uamaummuu non moumo m .Boum non mxmmun N.N vmwmuo>m NENNO h>momm .Soum non mxmmun N.N wowmuo>w Nawuo uanNp .ONN3 Oumuoa O.N m3ouch30 .mvN3 NNONNE N.N mnum3mn .80 mo. NNNNN N.N + N.NO N.N NN-N NNN. + NOONN 2N. N2 NN N O.NN+ N.NN N.N NN-N NNN. + NOONN 2N. N2 NN N NN.NN+ N.NN O.N NN-N NNN. + NOONN 2N. N2 NN N N.N + N.NN N.N mcoz N NNN NNNNNNON scum 2O 2O 2O NON OONNONNONOO “OmaNNmNN ON NNNNN 2N mwcmno N cam: ou munom .NNOONNOOO .ON NNONN 127 Average losses in these eight trials were 7.72 for untreated hay and 3.12 for forage sprayed with emulsified ME and KZCOB' In three trials respiration loss for KZCO3 treated Alf averaged 6.52 while losses for respective controls aver- aged 10.92. In F34 (Table 20) apparent respiration losses were re- duced by one third for KZCO3 treatments while ME alone and in combination with K2003 decreased losses by two thirds. In this trial respiration losses were related to mean DM content indi- cating that the greater effectiveness of ME in hastening dry- ing may diminish respiration loss to a greater extent than KZCO3 treatment. Apparent respiration loss measured in 28 cases regressed with interval to 602 DM yielded the equation y = 4.3 + -.503x with a correlation of -.60, P<.Ol. Dale (1979) reported that high environmental tempera- ture increased respiration losses more than did slow rate of drying. Forage allowed to dry in the shade or over a wet pud- dle had lower respiration losses than forage dried more quickly in direct sunlight. Increased drying rates after chemical treatment could reduce both time to reach 60 to 652 DM and swath temperature during this interval. Dale (1979) found lower respiration losses in windrowed than swathed hay. While this is consistent with her findings on the effects of solar radiation our data on reSpiration losses from F9 comparing swaths and windrows were variable and show no consistent trend. 128 Leaching losses due to rain at 4 hours (F9) and at 30 hours post cutting in Dale's research cannot be separated from respi- ration losses and may be responsible for our different findings. Dry Matter Losses from.Mowing and Raking as a Function of Chemical Treatment and Method of Estimation Estimation of DM losses after mowing and raking by hand picking leaf and stem fragments from a given area were twice as large as estimates of field raking loss alone as determined by vacuuming up material left on the ground (F35; Table 21). Either method gave values lower than the 3 to 112 losses reported by Barrington and Bruhn (1970) or the 5 to 202 DM losses from mowing and raking reported by Keener et a1. (1973). Trial F35 was conducted in a pure stand of second cut- ting alfalfa which had experienced extensive leaf hopper dam- age. Our low values for raking loss may have been due to the short time of field exposure to reach 60 to 652 DM, 4 hours for treated and 6 hours for control, and to the relatively slow speed of 3.5 mph at which the hay was raked. In addition in- sect damage resulted in a high initial DM content (352) and could have changed relative drying rates of leaves and stems, providing more uniformly dry material at raking. Because the hand picking method includes mowing losses it would be expected to give greater values than the estimate of raking losses alone as calculated by difference using the vacuum pick up method. comm Sony omuomuun9m mmB mEmNm N.NN mo ammuu NmscNmmN cam mmmmoN mNN3OE mo mumENumm Nd 129 omNoNQ mNm3 mGNNmN cam ch30E .mmumfiflumm onNm .moosume 03¢ mama» mo monmummmwo ms» Eonmm .mst> o .ocmn >9 m5 ocwuac ucmNm map Eonm ommoonNG unmemmum Emum can mmmqo N no name Eoum cmumNsono was ¢m\zo ox N.Nomm mo onNw n .mmumowammu mmunu mo :mmzm NN.N O.NN N.N m Nhhux NNN. + 00 N 2N. N2 NN NN.N O.NN N.N mcoz mmmon mcwsoz nmumENumm NN.N NN cm.N m Nhhnx NNN. + 00 N 2N. m2 NN mo.N om om.m mcoz ”conumz Esnom> n NN.N hm N.N m Nhhlx NNN. + 2 00 N 2N. m2 NN NN.N Hm N.N mcoz "conumz OOauNONN OONN nonNN Nmuoa mo N mm mm\mN Hmumz Um\mmoq so NONumflnomma unmEummNa mmoq ammz mmoq 2mm: mfimnm mammz .moonumz 039 an omumENumm mm mngmm tam ch3oz Eonm mmmmoq Hmuumz NNO .NN mNnma 130 Estimates of mowing losses calculated by subtracting the vacuumed estimate from the hand picked estimate were 1.2 to 1.42. Slightly greater mechanical losses were detected for the sprayed alfalfa by both methods. If this difference is expressed as a ratio of losses for sprayed hay to losses for control, values of 1.07:1 for hand picked and 1.28:1 for vacuum methods are obtained. These results, preliminary in nature, indicate that treatment of alfalfa with ME, K2C03 emulsions can decrease the interval between cutting and raking without causing ex- cessive leaf losses like those reported by Sheperd (1959) after desiccation of alfalfa with contract herbicides. Changes in Amounts of Dry Matter, Bale Temperatures, and Analytical Values of Baled Hay During Storage As A Function of Dry Matter Content and Chemical Treatment Hay reached an average of 782 DM in 11, 25 and 50 hours in trials F10, F34 and F20 respectively while unsprayed hay baled at these same times post cutting had reached an average of only 662 DM (Table 22). Dry matter losses during 25 to 51 days of storage were greater for control than for bales of sprayed hay, averaging 9.5 and 5.82 respectively. Mean bale temperatures were also greater for control than treated forage (34.l>31.9° C at 131 Numdn umnsmfiom vNoa on .cmmNo N.N- u: nu NNN Nm o.NN O.N mN. N. 0.0 N Numsv um£3mEom uNoB on .cmmNu m.on .. .. NNN Nw O.NN m.N mN. N. m.o m human hnm> pNoa on .NmmNU N.N: u: .. NNN mm m.mN m mN. N. n N Numdt uoc NNoB oc .cmmNu N.O- u- Nun NNN Nw o.mN o o o o N NNN Numdu no: vNoE o: .cmmNu N.O- wN mm wNm NN m.NN N.N m. N. N.N m human Non wNoB on .cmmNu N.m NON om wNm on O.NN N.N m. o N.N N human Non vNoB on .cmmNo N.N NNN om mNm ow n.0N N.N o N. o m NNODN Non pNoE o: .nmmnu m.m NNN Nm wNm on o.om o o o o N vNoE muN£3 NNONNO .NNONN N.ON NNN ON NNN NO N.NN O O O O N NNN vNoa on .cmmNu N.N NNN NNN mmm mm o.om N mN. N O.N N UNoE momwnam muN£3 .NBon N.ON vmm NNN «mm no o.on o o o o N ONN vNoa on .cmmNu N.N NNN NN mmN NN o.NN N mN. N N.N N nNoE muan NONNNO .csoNN O.N NNN ON NNN NO O.NN O O O O N ONN a N5 ONONN mmoN 2mm: xmmm mwmuoum chNmn waNNmn mooNN mm: 9N NNNNH um>Nmmno NNDON> 52D .mEmH mNmm :N ONNQ um ESQ on mBNH a Nu NNoOmn ucmBuNmNH .mNmNNH vaNm m>Nm now mwmuoum waNNnn mmOOoN Hmuumz NNN Nam NmNnNmNmaamH mNmm .chNmm um ucmucoo Nmuumz_hno .waNNmm on wcwuuno Scum NN>NmucN .NN mNan 132 .NNo.vmv ucmummwNn mum NmNNu mama .Amo.vmv uamumNMNv mum NmNuu mEmm .AON.vmv ucmNmMMNw mum NMNHu mawm mmNmn Eouuon co wNoB mowmusm muN£3 humsv c3oum mmNmn Eouuon co uNoE momm Imam muN£3 mEOO cam c3oun .Cmmuw hNumoE HONOU .Nmm NNNHu m QN .uszmB SQ NmNuNcN mo N ON mmON numuuma haw mo uszws Nmsuom u 29 m.N NN mN ¢.m mNm MN mnu CN muaNuomNanm ufimHmNmNc nuN3 mmst> NN NN NNummno NmDmN> 0o mmON cmmz xmmm nzn .Oame mNmm HO mmmuoum waNNmO waNNmO ION 02m OOOONN mm: ON NONNN GN m%ma um H29 ou GENE :ONumNHommn ufigaummuh .OmsaNuaou .NN ONOON 133 P<.10 in trial F10; 33.0>13.8° C at P<.05 in F20; and 36.7>28.0° C at P<.Ol in trial F34, Table 22). Control bales stored at 64 to 68% DM developed patches of white mold and turned brown in color during storage while treated bales stored at 77 to 792 DM did not mold and re- tained green color in the three trials. Both treated and control hay increased in DM content during storage attaining approximately equal DM content, rang- ing from 78 to 90% at the end of storage. Ash, fiber frac- tions, crude protein (CP) and Acid detergent fiber (ADF) bound nitrogen (N) usually increased during storage. Magnitude of these increases was generally greatest for control bales in- dicating larger losses of non-fibrous constituents had occurred during storage of the wetter control bales. A large reduction in water soluble carbohydrate (Soly CHZO) concentration oc- curred during storage in both treated and control bales in F10 but Soly CHZO decreased only in control bales in trial F20 (Table 23). These data suggest that fiber fraction and C? were re- latively stable during heating up to 50° C while reductions in Soly CH20 concentration of 34 to 562 occurred in bales that attained 40° C and had mean temperatures of 30° C. These results are consistent with the work of Nelson (1966) who reported DM losses of 8 and 11% for hay baled at 73 and 612 DM respectively, and Fetenstine (1971) who found 134 Table 23. Analytical Values for Control and Sprayed Alfalfa at Baling and After Storage. Control Treatedh Trial. Initial Final Difference Initial Final Difference F10 m 64.9 82.6 17.7 76.8 84.7 7.9 Asha 7.98 8.04 .06 8.25 9.0 .75 ADFab 35.4 41.0 5.6 34.2 39.0 4.8 mac 50.0 57.2 7.2 46.4 53.3 6.9 Herricellulosea 14.7 16.4 1.7 12.3 14.3 1.6 1 CPad 16.9 18.9 2.0 16.9 18.6 1.6 ADF-Ne, as Z of total N 12.07 11.99 -0.08 10.77 11.55 0.78 Soly CHZOaf 7.57 4.12 -3.45 5.95 3.32 -2.63 IVDMDg 59.67 56.39 -3.28 58.27 57.39 - .88 1'20 m 64.6 78.6 14.0 76.3 77.9 1.6 Asha 8.56 10.03 1.47 7.93 8.11 0.18 ADFab 29.1 34.1 5.0 28.6 29.1 0.5 mac 41.8 52.5 10.7 41.7 43.1 1.4 Hemicellulosea 12.8 18.4 5.6 13.1 14.0 0.9 2 CPad 18.8 20.4 1.6 17.6 18.6 1.0 ADF-Ne/N z 8.05 11.90 3.9 7.11 7.80 0.69 Soly c1120af 11.00 6.65 -4.35 11.89 13.17 1.28 mums 68.1 64.8 -3.3 67.3 66.0 -1.3 135 1e5u223. (kmthmmflw Oxuxol - —- Tnanedh Trial Initufl. Ehrfl. Dififinmmce Initnfl. Fhrfl. Dififiarmce F35 an 74.9 85.1 10.2 77.2 83.3 6.1 Agh? 7.20 8.72 1.52 6.97 7.27 .30 ADFab 33.4 33.2 - .2 31.2 32.2 1.0 cwac 48.3 55.0 6.7 50.1 52.1 2.0 HEmicellulosea 14.9 21.8 6.9 18.9 19.9 1.0 2 cpad 17.1 19.3 2.2 15.9 16.1 .2 AnseNe/N'z 8.35 9.15 .8 8.30 8.16 - .14 s61y (II-1208f 7.8 8.1 .3 8.5 6.6 -1.9 Ivnmnag 65.4 62.8 -2.6 63.8 62.9 -o.9 afiqnmsmaias Z<fl5DM. tkDF==acfl1deflaggntifiber. ccw = cell walls. “‘89 = crude protein N x 6.25. eN==nIUngn. fgthCHdD==waUarsohflfleuaninhwhmme. 5DEMD==inxdxrochytmnxercfisamxmmmmxn hSee Table 22 for treatment description. that Soly CHZO cOncentration in alfalfa decreased with increas- ing temperatures from 27 to 70° C while cellulose and hemi- cellulose were not degraded by temperatures in this range. This author also reported no loss of CP in heated alfalfa but found increases in fiber bound N. 136 In the previously described trials all hays were baled at the same time but in trials F31, F34 (treatments 2 to 5) and F35 the experimental hays were all baled at the same DM. Interval from cutting to baling at 78 to 822 DM aver— aged 39 hours for 2 untreated hays and 24.5 hours for 4 treated hays (F31 and F34, Table 22). In trial F34 ME + EM and K2C03 treatments alone were less effective in reducing hours to baling than the 3 component solution (Control, 30.0 > ME + EM, 28.0 > K2C03, 26.5 > ME + EM + KZCO 24.5 3. hours; Table 22). Dry matter loss and mold development during storage were not detected for any treatment in F31 but all sprayed hays (groups 2, 3, and 4) were dusty while control bales were not. Losses of UN for sprayed and unsprayed hay baled at 78 to 792 DM in F34 (groups 2 to 5) were small and generally similar between treatments while no differences in mean tempera- ture, peak temperature or visual quality measurements were observed (Table 22). Analytical values were similar for control and sprayed hay when baled at about equal DM.contents (77 to 822; F31 and F34; Table 24). Small increases in fiber fractions and CP as a Z of DM occurred during storage. Magnitude of these changes was not related to chemical treatment at cutting. Increases in fiber bound N were also small with the exception of control number 2 in trial F34 where ADF/N increased from 8.1 to 132 of total N. 137 N.O N.OO O.NO N.N 0.00 N.OO O.O N.NO N.OO O.O 0.00 N.NO mega O.N- 0.0 0.0 O.N- N.N N.O N.O- N.N O.N N.N- N.O N.ON NeONE Dom O... N.ON N.NN O.N O.NN N.ON O.O N.ON N.ON N.O- O.O N.NN N E8289. m. O.ON N.ON O. 0.0N N.ON N.N O.NN 0.0N N. - 0.0N N.ON News N 0.0 O.NN 0.0N N.N 0.0N O.NN N.O- 0.0N N.ON O.N N.ON O.NN ooOONON -Noosmm O.N N.NO O.NN N.N O.ON O.NN 0.0 0.0N 0.0N 0.0 0.0N N.NN 665 N.N O.NN N.ON 0.0 0.0N 0.0N 0.0 N.ON N.ON 0.0 N.ON O.ON 8.834 N. OOO ON: ON. OON NN.N OO. NOO «N.O ON. OOO O: are... O.N N.OO O.NO O.N 0.00 N.NO O.ON N.OO O.NN N.O ONO N.NO E NN.N .N... . .ON 3 SENONONO N Fe 335 888mg Name. N353 888mg N :N N303 888mg NomNeN NmNONtN N35. £6888. N888 . owmuoum wand Oowfié O8 “8082 be NNO B R om 8N3 me. 858:. Beam one. BNEE you 883, 33%st .NN SOON. 138 O.O- N.OO O.NO N.O- O.OO O.NO Nessa 0.0- OO.N N.O O.N- N.O N.O NeONE New 83 NOON ONO NOO NN.NN OO.O N 302-5 N.N 0.0N O.NN. O.N O.NN :N 88 N N.N- O.NN O.ON O.N N.ON N.ON 8683 -NooNEN O.O O.ON O.ON O.O O.OO O.ON 83o O.O O.OO N.OO O.O N.OO O.ON 8.8 NO. BO OON OO. ONO NON are... N.N N.OO O.ON O.NN ONO N.OO E NON 88082 N65 N335 868mg Noam 335 N83. N Nofiooaor N .vmnnNucoo .NN oNan 139 .coNumNHommv “Nam—58H. now NN mNan mom: .oocmhmoaammNo .5qu .06 oHNN> NNN u GEE/Hm . 36.8.3380 oNnNNNom “sum? .1. on0 30mm .cmOonNNd n zNw OfiOxzfiBBO8BonBO .mNNms NNmoo .1. Bo .HOONN oeowuoooo ONoo n OOOO .5 mo N no ommmmugm O.O N.NO N.NO O.O- O.NO O.OO O.N- N.OO O.OO Nessa O.- N.O .N.N O.N- N.O NO.O e.- N.N O.N NeONE NNoO ON.- OO.ON OO.ON NO.- OO.O NN.O OO.N OO.ON NO.N N zNoz.OO< O.N N.ON O.ON N.N O.ON N.NN N. N.ON N.ON Ooeo N O.O O.ON O.ON O.N O.ON O.ON O.O N.ON N.ON eoeoNeN -Nooeaoz O.- N.ON N.OO O.O N.ON O.ON N.O N.OO O.OO 6630 N.- N.OO O.OO O.N O.NO ,O.OO O.- N.NN O.NO OOOOO ON. NN.N NN.N NN. OO.O NN.N O. OO.O OO.O area O.O O.OO N.ON O.N O.OO N.ON N.O O.OO O.ON Uza NON oaflflfiOfifiefiflsNoafiflflosfimsflENoafiflhosfiesflEN N38 O O O .OooeNoeoo .NN ONOON 140 Hay was baled at 75 to 77% DM in trial F35 to deter- mine if chemical treatment applied at cutting would influence changes in quality of hay baled at a DM content generally ac- cepted to be the lower limit for safe storage without exces- sive heating and DM loss (Hodgson, 1948). Interval from cutting to baling at 75 to 77% DM was only 6.0 hours for sprayed and 7.5 hours for control alfalfa in F35, this short interval was due to extensive leaf hopper damage which resulted in an initial DM content above 302. Mean bale temperatures were greater for control bales (32.4 > 23.4 at P<.05 in F35; Table 22). Dry matter losses were small for both treatments but were slightly greater for the wetter control bales (3.9 > 2.92; Table 22). Increases in ash, cell walls and CP were also greatest in control bales (Table 23). On the other hand treated bales were brown and dusty when opened while control bales were primarily green and not dusty. In conclusion, alfalfa sprayed with the three component solution had a higher DMZ than unsprayed alfalfa baled at the same time in three trials. Mean bale temperatures, DM loss and increases in concentration of Ash, fiber, CP and ADF-N were greater for these control bales than for the drier sprayed hay. Water soluble carbohydrate concentration de- creased dramatically in two trials where bale temperature during storage averaged greater than 30° C, thus increases in fiber fractions and CP expressed as a Z of DM may in large part be due to losses of Soly CHZO during heating. 141 Hours from mowing to baling at a DM of 75 to 822 were greater for unsprayed control hay in 3 trials while analyti- cal values for the resulting hay at baling, bale temperatures, DM loss, and changes in visual and analytical quality measure- ments during storage were usually similar for these control and sprayed forages. SUMMARY The present research extended previous investigations of chemical treatments that hasten forage drying, and clari- fied several questions brought up by the investigations of Tullberg and Angus (1972 and 1978), Tullberg and Minson (1978) and Wieghart et a1. (1980). In addition several new areas of investigation were identified. Drying of alfalfa was hastened by the use of spray solutions containing carbonates or other salts of the alkali metal group and was influenced by both the cation present and solution pH. Effectiveness was generally enhanced as cationic radius increased (Li < Na < K < Rb < Cs) and as pH increased for solutions containing potassium salts. Potassium and sodium carbonate are readily available, relatively inexpensive, non caustic and both produced satis- factory increases in drying. The greater effectiveness of K2C03 prompted us to use it in experimental studies while cost effectiveness of these two compounds will need to be determined in future studies. Drying hastened by use of K2C03 solutions was not enhanced by additions of surface active agents or by application of solution volumes greater than 22 of fresh forage weight. Results from drying trials utilizing K2003 were variable, sometimes showing dramatic 142 143 increases in drying after spraying with K2C03 and sometimes showing little advantage for use of this compound. Reason for this variability is not apparent. Methyl esters of long chain fatty acids (ME) have previously been shown to increase drying rates (Drt) of cut alfalfa (Wieghart et a1., 1980). In the present studies ME added to K2C03 solutions usually increased mean Drt and DM compared to use of either component alone. Responses to‘ spray treatments with emulsified ME and K2C03 appeared to be additive, and variability of response was also reduced. Ef- fectiveness of applied ME was increased when an emulsifier was added or when liquid application rates were increased. The minimum effective application of ME in K2C03 solutions was approximately 0.5 gr ME/kg while increasing application rate of ME above this amount increased drying, reaching a maxi- mum.of 1 to 3 gr ME/kg. Drying rates for both control and treated forages di- minished over time and as WC decreased. Potassium carbonate increased Drt primarily during the early stages of drying while ME increased Drt over a longer interval and maintained an increased Drt above control until WC reached at least 0.5 (672 DM). Spray treatment with the three component solution increased Drt primarily during the first 8 to 12 hours after treatment compared to untreated controls but Drt appeared to be more closely related to WC than to time after treatment. 144 The three component solution consistently increased Drt of alfalfa in the laboratory down to a WC of 0.5. Treatment differences in DM content established during the initial period when Drt was increased by chemical treatment, were usually maintained during the final stages of drying. Re- ductions in field drying time required to reach 802 DM of 10 to 24 hours were demonstrated in several trials. Treatment of different forage species with the three component solution influence Drt to different extents. Dry- ing rate at a given water content (WC) was greatest for treated Alf > treated Bft > treated RC, while Drt of two temperate for- age grasses, brome grass (BG) and orchard grass (0G), was not affected by chemical treatment. Grasses had higher initial DM content and at a given WC had more rapid rates of water loss than did unsprayed alfalfa. Spray treatments tended to equalize Drt of Alf and BG. Sprayed alfalfa of different maturities or grown under field or "greenhouse" conditions dried more rapidly than did respective controls. These re- sults indicate that the three component solution can hasten drying of alfalfa grown under different environments and of different maturities. Field application of the three component solution in- creased mean DM.under a wide range of environmental conditions. Drying of alfalfa was more rapid when swathed than when placed in a windrow. Swathed alfalfa or sprayed alfalfa was usually 145 drier at the end of the day or at the onset of rain, than was windrowed or untreated alfalfa. This drier forage picked up more moisture from dew or rain than did windrowed forage or untreated control swaths. Swaths or treated swaths attained a greater DM content during early drying than did windrowed or untreated alfalfa. This greater DM content was maintained after dew or light rain. Dry matter loss from.continued respiration during drying was generally less for sprayed alfalfa than for un- treated control. Methyl esters appear to be more effective than K2C03 in reducing respiration loss and this may be related to increases in Drt when ME were included in the spray solution. Mechanical losses of DM from mowing and raking were slightly greater for sprayed than unsprayed alfalfa but losses of DM during these operations were less than some reported values for unsprayed alfalfa. Alfalfa sprayed with the three component solution had attained a greater DMZ thquntreated control when both were baled at the same time. Bale temperatures, DM loss, and changes in visual and analytical quality measurements during storage were greatest for these control bales. Interval to baling at a DMZ "safe" for storage was substantially re- duced by spray treatments while analytical values of treated and untreated forage at baling, bale temperatures and changes in visual and analytical quality measurements during storage were usually similar. 146 The present research has demonstrated that the length of exposure time for alfalfa sprayed with the three component solution can be reduced under a variety of conditions without a reduction in quality of the final product after harvest and storage. Thus the use of this technique in alfalfa harvesting systems in the midwestern United States should increase the quality of harvested alfalfa by reducing the likelihood of exposure to adverse weather during field drying. New areas with potential for further research have been identified and include 1) study of cost effectiveness of spray treatments containing sodium or potassium carbonate alone or in combination with emulsified ME, 2) tests to determine the effectiveness of the three component solution on drying of temperate and tropical grasses and legumes, 3) measurement of rates of drying as influenced by environmental conditions during plant growth and during drying, 4) development of field application systems to obtain more complete coverage with small volumes of water, and 5) long term field studies evalu- ating savings in harvested nutrients per Ha, animal intake and production, and cost effectiveness of utilizing chemical: treatments to hasten drying in commercial farm operations. REFERENCES CITED REFERENCES CITED Ajibola, 0., R. Koegel, and H. D. Bruhn. 1980. Radient energy and its relation to forage drying. Transactions of Amer. Soc. Agric. Engin. 23:1297. Audus, L. J. 1964. The physiology and biochemistry of herbi- cides. Academic Press, London and N. Y. Bagnell, L. 0., W. F. Miller, N. R. Scott. 1970. Drying of the alfalfa stem. Transactions of the ASAE 13:232. Barrington, G. P. and H. D. Bruhn. 1970. Effect of mechani- cal forage harvesting devices on field curing rates and relative harvesting losses. Transactions ASAE 13:874. Bleckman, C. A. 1980. Cuticular ultrastructure of prosopis velutina and Acacia—Greggi leaflets. Botanical Gazette 141:1. Blair, E. H., H. L. Mitchell, R. E. Sliker. 1953. Industrial and engineering chemistry. Industrial Ed. 45:1104. Boyd, M. M. 1959. Hay conditioning methods compared. Ag. Eng. 40:663. Bruhn, H. D. 1959. Performance of forage conditioning equip- ment. Ag. Eng. 40:667. Byers, G. L., D. G. Routely. 1965. A study of factors affect- ing the release of moisture from cut alfalfa. Proc. 9th Int. Grasslands Cong. Sao Paulo 1:595. Chambers, T. C. and J. V. Possingham. 1963. Studies of the fine structure of the wax layer of sultana grapes. Aust. J. Biol. Sci. 16:818. Clark, B. J. and P. McDonald. 1977. The drying pattern of grass swaths in the field. J. Brit. Grassland Soc. 32:77. Coitti, A. and A. Cavallero. 1980. Haymaking losses in cocks foot-Lucerne mixtures in relation to conditioning and degree of drying at harvest. European Grassland Federa- tiogiAProceedings of Symposium.No. 11, Brighton UK. P. . 147 148 Dale, J. G. 1979. Simulation of alfalfa harvest losses. MS Thesis. Purdue University. Dubois, M., K. Gilles, J. K. Hamilton, P. A. Rebers and F. Smith. 1951. A colorimetric method for the determina- tion of sugars. Nature. 168:167. Eglinton, G. and R. J. Hamilton. 1967. Leaf epicuticular waxes. Science 156:1322. Eglinton, G., A. G. Gonzalez, R. J. Hamilton and R. A. Raphael. 1962. Hydrocarbon constituents of the wax coatings of plant leaves: a taxonomic survey. Phytochemistry 1:89. Fairbanks, G. E., G. E. Thierstein. 1966. Performance of hay conditioning machines. Transactions ASAE 9:182. Festenstine, G. N. 1971. Carbohydrates in hay on self heating to ignition. J. Sci. Food. Agric. 22:231. A Fisher, R. A. 1968. Stomatal opening: role of potassium, ac- tive uptake by guard cells. Science 160:784. Gallander, J. F. and A. C. Peng. 1980. Lipid and fatty acid composition of different grape types. Amer. J. Enology and Viticulture 31:24. Green, R. M. 1975. Microclimate and resistances to water loss in the hay swath. Grassland Research Institute annual report, p. 70. Green, R. M. and B. M. Jagger. 1977. Microclimate, energy exchange and water loss from the hay swath. Grassland Research Institute annual report, p. 74. Green, R. M., J. L. Prickett, and J. Bennett. 1976. Micro- climate, energy exchange and water loss from.the hay swath. Grassland Research Institute annual report, p. 77. Grncarevic, M. '1963. Effect of various dipping treatments on the drying rate of grapes for raisins. Amer. J. Enology and Viticulture 14:230. Grncarevic, M. and F. Radler. 1971. A review of surface lipids of grapes and their importance in the drying process. Amer. J. Enology and Viticulture 22:80. Hall, D. M. 1966. A study of the surface wax deposits on apple fruit. Aust. J. Biological Sci. 19:1017. Hall, D. M. and R. L. Jones. 1961. Physiological significance of the surface wax on leaves. Nature 191:95. 149 Hall, G. E. 1964. Flail conditioning of alfalfa and its effect on field losses and drying rates. Transactions of the ASAE 7:435. Harris, C. E. 1975. Effect of chemical desiccants on the dry- ing rate and respiration of perennial ryegrass leaves. Grassland Research Institute annual report. Harris, C. E. 1979. Water loss from isolated plant parts under controlled conditions. “Grassland Research Institute annual report. Harris, C. E., R. Thain and H. I. M. Sarisalo. 1974. Effective- ness of some mechanical, thermal and chemical laboratory treatments on the drying rate of leaves and stem inter- nodes of grass. J. Agri. Sci. 83:353. Harris, C. E. and J. N. Tullberg. 1980. Pathways of water loss from legumes and grasses cut for conservation. Grass and Forage Sci. 35:1. Hayward, H. E. 1938. The structure of economic plants. McMillan Co., New York. Hodgson, R. E., R. E. Davis, W. H. Hosterman and T. E. Hienton. 1948. Storage of forage, p. 161 in Grass-Yearbok of Agriculture. 1948. Washington, D. C. Hoglund, C. R. 1964. Michigan Agr. Exp. Econ. Report 947, p. 16. Holloway, P. J. 1969. Chemistry of leaf waxes in relation to wetting. J. Sci. Food and Agric. 20:124. Honig, H. 1980. Mechanical and respiration losses during pre- wilting of grass. European Grassland Federation, Pro- ceedings of Symposium No. 11. Brighton UK, p. 201. Jeffree, C. E., E. A. Baker, and P. J. Holloway. 1975. Ultra- structure and recrystallization of plant epicuticular waxes. New Phytol. 75:539. Johns, G. G. 1972. Water use efficiency in dry land herbage production. J. Aust. Inst. Agric. Sci. 38:135. Jones, L. 1973. Water loss from isolated plant parts under controlled conditions. Grassland Research Institute annual report. Jones, L. and J. C. Prickett. 1977. Water loss from the swath. Grassland Research Institute annual report. 150 Jones, T. N. and L. 0. Palmer. 1932. Field curing of hay as influenced by plant physiological reactions. Ag. Engin. 13: 199. Keener, H. M. , W. L. Roller and W. E. Gill. 1973. Expected forage quality and quantity for different harvesting systems in Ohio. Proceedings of the third alfalfa sym- posium, Wooster, Ohio. Kennedy, W. k. , W. H. Hesse and C. M. Johnson. 1954. Effect of herbicides on the drying rate of hay crops. Agronomy J. 46:199. Klinner, W. E. 1975. Design and performance characteristics of an experimental crop conditioning system for diffi- cult climates. J. Agr. Eng. Res. 20:149. Klinner, W. E. 1976. ‘Mechanical and chemical field treatment of grass for conservation. Annual Conf. Inst. Agr. Eng. Report No. 21, London. ' " ' ‘ ' Klinner, W. E. and G. Shepperson. 1975. The state of hay mak- ing technology.” A Review. J. Brit. Grassland Soc. 30:259. Krutz, G. W. and D. A. Holt. 1979. For fast field drying of forage crops. Ag. Eng. 60:16. Leshem, Y. , R. Thaine, C. E. Harris and R. J. Canaway. 1972. Water loss from cut grass with special reference to hay- making. Ann.App1. Biol. 72:89. Nelson, L. F. 1966. Spontaneous heating and nutrient retention of baled alfalfa hay during storage. Transactions of ASAE 9 509, Nagarajah,S. 1979. The effect of potassium deficiency on stomatal and cuticular resistance in tea leaves (camel- lia Sinensis). Physiol. Plant 47:91. O'Toole, J. C. and R. T. Cruz. 1979. Leaf rolling and transpira- tion. Plant Sci. Letters 16:111. Pallardy, S. G. and T. T. Kozlowski. 1980. Cuticle development in the stomatal region of populus clones. New Phy. 85:363. Pederson, T. T. and W. F. Buchele. 1960. Drying rate of alfalfa hay. Ag. Eng. 41:86. Pederson, T. T. and W. F. Buchele. 1960. Hay in a day harvest- ing. Ag. Eng. 41:172. 151 Person, N. K. and J. W. Sorensen. 1970. Comparative drying rates of selected forage crops. Transactions ASAE 13:352. Petrucci, V., N. Catata, H. R. Bolin, G. Fuller and A. G. Stafford. 1974. Use of oleic acid derivatives to accelerate drying of Thompson seedless grapes. J. Amer. Oil Chem. Soc. 51:77. Philipsen, P. J. J. 1969. Methods of drying and changes in the crop especially after killing the standing crop by thermal treatment. European Grassland Federation Proc. of 3rd General Meeting. Braunschwig p. 77. jPriepke E. H., and H. D. Bruhn. 1970. Altering physical characteristics of alfalfa to increase the drying rate. Transactions of the ASAE 13:827. Schieferstein, R. H. and W. E. Loomis. 1956. Wax deposits on leaf surfaces. Plant Phys. 31:240. Schonherr, J. 1976. Water permeability of isolated cuticular membranes: the effect of pH and cations on diffusion, hydrodynamic permeability and size of polar pores in the cutin matrix. Planta 128:113. Schukking, S. and J. Overvest. 1980. Direct and indirect losses caused by wilting. European Grassland Federation, Proceedings of Symposium, No. 11, Brighton U. K., p. 210. 5311eperd, J. B., H. G. Wiseman, R. E. Ely, C. G. Melin, W. J. Sweetman, C. H. Gordon, L. G. Schoenleber, R. E. Wagner, L. E. Campbell, G. D. Roane and W. H. Hosterman. 1954. Experiments in harvesting and preserving alfalfa for dairy cattle feed. USDA Tech. Bull. No. 1079. ESIrepherd, W. 1959. The effect of a chemical desiccant on the speed of curing hay. J. Aust. Inst. Ag. Sci. 25:218. Shepherd, W. 1964. Paths and mechanisms of moisture movement in detached leaves of white clover. I. Losses of petiole moisture direct from petioles and via laminae. Annals of Bot. 28:207. Shepherd, W. 1965. Air speed effects during drying of harvested pasture material. Aust. J. Ag. Res. 16:385. SI'Ltte, P. and R. Rennier. 1963. Investigation of cuticular cell wall layers. Planta 60:19. 152 Spray Systems Co. 1977. Spray Manual Catalog 36, Agricul- tural spray nozzles and accessories, p. 3. Stafford, A. E., G. Fuller and H. R. Bolin. 1980. Loss of fatty acid esters from grape surfaces during drying. J. Amer. Oil Chem. Soc. 57:70. Stalfet, M. G. 1957. The water output of the guard cells of the stomata. Physiologica Plantarum 10:752. Sullivan, J. T. 1973. Chemistry and Biochemistry of Herbage. Vol. III, Chapter 27, Butler, C. W. and D. G. Bailey, eds. Academic Press, New York. Thaine, R. and C. E. Harris. 1973. Short note: formic acid as a desiccant for grass leaves. J. Agr. Sci. 80:349. Tinnimit, P. and J. W. Thomas. 1976. Forage evaluation using various laboratory techniques. J. Animal Sci. 43:1058. Tullberg, J. N. and D. E. Angus. 1972. Increasing the drying rate of lucerne by the use of chemicals. J. Aust. Inst. Agr. Sci. 38:214. Tullberg, J. N. and D. E. Angus. 1978. The effect of potas- sium carbonate solution on the drying of lucerne. 1. Laboratory studies. J. Agr. Sci. 91:551. Tullberg, J. N. and D. J. Minson. 1978. The effect of potas- sium.carbonate solution on the drying of lucerne. 2. Field studies. J. Agr. Sci. 91:557. Turner, N. C. 1970. Speeding drying of alfalfa hay with fusicoccin. Agronomy J. 62:538. Turner, N. C. and G. Antonio. 1969. Fusicoccin: a fungal toxin that opens stomata. Nature 223:1070. Vijaya, Raghavan, G. S. and W. K. Bilanski. 1974. Effects of alfalfa stem-leaves moisture difference on leaf loss during harvest. Canadian Ag Engin. 16:10. Wieghart, M., J. W. Thomas and M. B. Tesar. 1980. Hastening drying rate of cut alfalfa with chemical treatment. J. Anim. Sci. 51:1. Wilkins, R. J. and R. M. Tetlow. 1972. Water loss in conserva- tion systems: field studies. Grasslands Research Insti- tute annual report. 153 Wilkinson, R. E. and M. J. Kasperbauer. 1980. Effect of light and temperature on epicuticular fatty acids and fatty alcohols of tobacco. Phytochemistry 19:1379. Winkler, A. J., J. A. Cook, W. M. Kliewer and L. A. Lider. 1974. General Viticulture. Univ. of California Press, Ltd., p. 633. Zimmer, E. 1973. New methods in fodder conservation. Vaxtodling 28:90. 15 mwummunmum‘ IN 1 '1 I II E“ “'|' H S". 3 1293 IIHIHIHII