i 9553' ’ .;'o.. 75“; “9}; 43?. - ‘~ 00 w I § . g n t” ‘ I . I .- .«r;; 3 r0 ‘1' .9; < _I_I Io "vs: .1. f“. W4 ; 00‘. .0 .0“ c . . ‘ l ..7 . _-.. . A 4.- o o... ‘6-‘. —— o - .~ . O-Q ...-- -.-r-o - C . ---’... o ' ' I . . . ‘ ' f ., i . N I ext-,6”: £35393"? . ' t .‘I’ N4, 31‘“ , - - M .. . - t. . . . . ‘ ‘ ‘ ‘ x . L' . This is to certify that the b . thesis entitled * - A LABORATORY COMPARISON OF TIE ‘— . * - PHYTOTOXICITY OF SEVERAL DDT ' - " FORMULATIONS, AND AN EVALUATION " , ‘6 OF THE METHOD USED presented by i ' .. William D. Shea - . has been accepted towards fulfillment .‘ of the requirements for ~ . . .. ma. .degree inmlogy ; ,. H " E .. . i h \ .1 h o ' I L ' , ZL" iW L . . fi L . .6 Major professor . ,. a.’ ' , ’ I“ . ,. 3 ' 13..., 1 X MOM 19 5 t s d I h s f P» . r ‘ ‘ - 0-169 L ' ' g .. P 93”“: 6f ~ '. A 7 . '”‘§3€_3"‘Z"4”1~"f«i}.; "if” Q-‘ 317.. 7“ “ 1 , . T . ..\‘J T ' " ' l' . - ~ 1 l . - " fai-V: _ A ' a 5¥=«"-'?’th “as ' ~ - “ ”’5‘. ‘v . 3 . t - ‘I C \ ‘ ‘_: ' \‘n.‘IgL' L31“ ”.01 ._.l PLACE IN RETURN BOX to remove this checkout from your record. TO AVOID FINES return on or before date due. ‘ DATE DUE DATE DUE DATE DUE Institution quel Opportunity czwrchmJ-p t MSU Is An Affirmative Action/E A LABORATORY COMPARISON OF THE PHYTOTOXICITY OF SEVERAL DDT FORMULATIONS, AND AN EVALUATION OF THE METHOD USED BY WILLIAM DAVID SHEA 4 \‘ \ I. I. \ A THESIS Submitted to the School of Graduate Studies of Michigan State College of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of IMASTER 0? SCIENCE Department of Entomology 1953 THESIS (/3/5 3 Q ACKNOWLEDGEMENTS The author wishes to express his sincere thanks to Pro- fessor Herman King for his assistance rendered in the research and preparation of this thesis and to Professor Ray Hutson for his supervision and interest in the problem. He is also greatly indebted to Lowery Trumble for the photographing of the graphs reproauced in this thesis. fhe author extends his sincere thanks to Gordon Guyer for his time and effort in the photographing of the apparatus and the experimental results. Grateful ackowledgement is also due to Dr. Oswald Tippo, editor of the American Journal of Botany, and Professor arthur N. Galston of the California Institute of Technology for their permission to reproduce graphs found in the literature review of this thesis. TABLE OF CONTENTS Page Introduction ................................... 1 Literature Review ............................. 2 Apparatus and methodology ..................... 15 Apparatus .................................. 15 Nutrient Solution.... ...................... 17 Test Procedure............................. 18 Materials and Formulations................. 22 Results ....................................... 25 Discussion .................................... 55 Emulsifiers ............................... 35 DDT Formulations .......................... 57 Evaluation of Method ...................... 58 Summary .......................................' 42 Literature Cited .............................. 44 Appendix ...................................... 48 Test Data - Emulsifiers ................... 49 Test Data - DDT Formulations .............. 69 INTRODUCTION Phytotoxicity of insecticidal chemicals has for many years been a problem to the entomologist. Many workers have reported that DDT emulsions of different manufacturers varied in their toxicity to plants. The injury was usually attri— buted to the DDT or the solvent used. Emulsifiers have re- ceived little or no reCOgnition as agents in the phytotoxicity of agricultural Sprays. Therefore, these tests were under- taken to determine the phytotoxicity of emulsifiers and their relation to the toxicity of DDT emulsions. Eighteen emulsi- fiers and eleven DDT emulsions were tested. The test method used Was reported recently by Casida and ailen (1951 & 1951a). This method has been given the name "Wisconsin test" in this paper. The Wisconsin test in many respects parallels methods used to identify plant hormones. although methods used to determine plant growth regulators have been known to the plant physiologist for lbout forty years, the Wisconsin test is probably the first encounter with plant growth regulators for the entomologist. Therefore, this method was used to determine its possibilities and to evaluate it as a means of determining the phytotoxicity of chemicals by the entomologist. LITERATURE REVIEW A characteristic of DDT phytotoxicity is its variability. Species and varieties differ marnedly in their sensitivity to this insecticide. For example, Hervey and Schroeder (1946) reported a difference between Varieties of cucumber in their susceptibility to foliage injury from DDT. There was also a difference in response of some plants under different condi- tions and different plants under the same conditions. Cullinan (1949) has noted that when DDT was applied to the soil or to the plant foliage of certain sensitive plants growth will be retarded without any other obvious symptoms. This insecticide has rendered the seeds of many plants more susceptible to invasion by pre and post-emergence singing-off organisms. Lumsden and Smith (1948) observed that in ten to twelve days after kalanchoes were Sprayed with DDT the symptoms of epinasty, leaf fall and necrosis became evident. Chapman and allen (1949) reported that DDT acts as a growth promoting substance. The eXperiments of these authors showed that as the c ncentration was reduced injury disappear- ed and plant stimulation occurred at a definite level for each Species tested. There was also a greater stimulation when only the lower leaves of a plant were sprayed. Injured plants usu- ally recovered if the growing tip had not been damaged. A difference was noted in the foliage symptoms of different plants sprayed with DDT formulations. Characteristic cucum- ber symptoms appear as a chlorosis of the leaves which ad- vanced from the margin with the veins remaining green. The margins of the leaves are turned upward. Lower leaves ar necrotic, stunted and distorted. In general, the plants have smaller leaves, fewer blossoms and shorter internedes. Beans have the veins clelr and a general mottling and chlorotic condition which involves the entire leaf. The growth above the primary leaves is generally short compared with that of untreated plants. Tomatoes show a slight yellowing of the leaves. Potatoes have a dark green foliage. The above symp- toms are usually displayed at concentrations of insecticide recommended for insect control. Merrill (1949) found no marked interior alterations in the leaves of peach seedlings grown in soil containing two hundred pounds of technical grade DDT and seedlings which received two aerial applications of 0.125 percent technical grade DDT per acre. A chemical analysis showed that seedlings grown with a DDT residue of twenty five pounds per acre or more in the soil would have a lower carbohydrate and slightly higher nitrogen content then the untreated peach seedlings. The amount of dextrins and starch are reduced in peach seed- lings treated with DDT sprays or grown in soils containing DDT residues. a no 5. Spray injury, nutritional excess and the deficiency symptoms and weather injury may be very similar. It is nec- essary to inspect an unSprayed plant or tree before the cor- rect amount of injury may be determined. Foliage that has been injured by insects, disease, hail, wind or drought is more susceptible to spray injury than healthy foliage. There- fore, plants that are maintained in a healthy condition are injured less frequently by Spray materials. Only a very few correlations of weather and DDT in reSpect to plant injury have been reported in the literature. A few of these obser- vations are stated here briefly. Dudley (1947) noted trat the greatest amount of injury appeared in years having the greatest amount of rainfall. The injury was usually greatest when heavy rainfall followed the application of the ihsecticide. Other authors have noticed increased injury on wet foliage. Gunther et al. (1946) reported that DDT was not leached away by rainfall. Deposits persisted on the foliage forty days before fifty percent loss of the res- idue. It has been noted that trapical temperatures and humid- ities may decompose DDT comparatively rapidly. Hot dry weather hastens the loss of DDT from foliage, possibly by raising its volatility to an appreciable extent. Magie (1947) observed that DDT injury to gladiolus opcurs on warm sunny days. Lindquist et a1. (1946) reported that sunlight does not markedly decompose DDT. The insecticide was almost completely Stajle t3 u; 321 soluti in r‘ v . CM gas t “ . *XELQ. V‘L 3,, ‘h Ilc‘e ~ . t“~ M stable to ultraviolet light when in the solid form; but in oil solution it wis_slightly decomposed. The decomposition of DDT under certain weather conditions may be of significance in plant injury. Casida and allen (1951b) have shown in their Nisconsin test that the impuri- ties of the technical grade DDT and decomposition products of DDT were more toxic than the p,p'DDT. Of the impurities in the technical grade DDT, the inhibitory action of 2-(p- chlorOphenyl)-l,l,l,trichloroethanol helps to explain the field observations of some authors. It is the most volatile and water soluble impurity of the technical grade DDT. This might explain injury to wet foliage since it would be present in the greatest concentration in water solutian from the technical compound and its more rapid penetration in a gaseous state might explain the observations of Magie. Another pos- sibility of the toxic action of DDT involves the degradation to the highly toxic 4,4,-dichlorodiphenylacetic acid (DDA). The delayed effect of DDT in some cases where applications were made over a period of time suggest'that the toxic action may be due to metabolism. Casida and Allen state that DDA in- hibits primarily by affecting mehbrane permeability. They also report that the hydogen—ion-concentration was critical in the growth responses of plants treated with DDT. An in- creasing toxicity with an increasing hydrogen-ion-concentra- tion was noted. Many other factors are important in the phytotoxicity of DDT. These factors for a given location remain relatively constant throughout the growing season and will not be con- sidered in this paper. However, a ground dust, an impregnat- ed dust, an emulsion, a solution a wetting agent or a sol- vent may be a new factor. The use of lime as reported by Cullinan (1949) increased the toxicity of DDT. Lumsden and Smith (1948) tested various formulations of DDT on the halanchoes. These tests indicated th.t the most severe injury resulted from emulsions, less from suspensions and least from dusts. The aerosol grade snowed less injury than the technical grade. However, in the emulsions both grades produced equal injury. Tester and Heigel (1949) have shown that the unknown wetting agent in a DDT wettible powder caused signifiCant re- duction in average plant weight of Triumph bush lima beans. This wetting agent also intensified plant injury. The wetting agent caused no signifiCant injury by itself. Wilson and dleesman (1948) noted a difference in the 'toxicity of DDT formulations of different manufacturers. These alzthors have noted that when talc, clay, and bentonite when lksed as conditioners of DDT stunted in that order, but that tfle talc would have caused less injury if these'materials had beean applied alone. The oil-soluble form of DDT Known as Deésnol caused marxed stunting of plants. This formulation 8180 caused a marked reduction in the traHSpiration of potato and tomato plants. Most insecticides have been found to de- press rather than accelerate tranSpiration. Substances readily soluble in water are more toxic than substances sparingly soluble in water eSpecially if conditions favor a high rate of eVaporation. With compounds of low Vapor pressure the available evidence indicates that in acueous Sprays entry is confined to the epidermis and that the pen- etration is largely arrested once the spray drOphets have dried out and the substance is deposited on the leaf (Blackman, 1952). Emulsions penetrate more slowly into the leaf than pure oil applications and cause less injury. auick breaking emul- sions were usually more injurious since they leave a contin- uous oil film (Brown, 1952). In general, formulators of insecticidal formulations do not maxe public the kind of surface-active agent used'in their Sprays. Therefore, the toxic effects of these compounds have not been reported. However, a few workers have reported how they affect the deposit of Spray materials. Ebeling (1939) has shown that both wetting and Spreading are functions of the contact ang e. The nature of the sub- stratum has a great influence on the Contact angle. Thus, leaves of different ages on the same plant and on different Sides or portions of the sane leave cause variations in Contact angle of a given liquid. Ben-Amotz and Hoskins (1958) found that the greatest deposits were obtained with the least stable emulsions. Brown and Hoskins (1958) found that as a general rule the more acid the system the greater the deposit. Surface-active agents Can be classified as.non-ionic, anionic and catonic. Emulsifying agents, in gener.1, are non-ionic. disley and Wood (1952) in their book "Encyclo- pedia of Surface-active agents" give the classification, prOperties and the application of many surface-active agents. Casida and allen (l951a,b) have reported two methods for evaluating insecticidal inhibition and stimulation. These tests were used in tuis paper for testing the emulsifi- ers and DDT formulations. Therefore, the folldwing part of this review is concerned with the literature relating to the method used. The Wisconsin test in many reSpects parallels methods used to identify plant hormones. Went (1957) has defined two of these tests. They are the ivena test and the split .Pea.test. The Avena test is carried out by applying the mate- ieal to be tested, dissolved in agar, to one side of a diSCapitated coleOptile of Avena_§ativa. This substance enters tkle coleOptile to which the agar is applied. In the presence 0i? auxins growth is promoted giving a rise to a curvature WhLich.within limits is prOpOPtiJndl to the concentration of ac'tive substance. standard conditions have been defined ani must be (carefully followed. The Split pea test depends upon the curvature of stem sections of etiolated EEEEB seedlings. Four-cm. sections which are split longitudinally down the center will curve towards one another in active solutions. The curvatures in this case are prOportional, within limits, to the logarithm of the concentration of active substance. Vent (1937) has summarized all the physiological details and the literature of both these tests in his book "Phytohormones". One important difference between these two tests is that many substances active in the pea test are not active in the Avena test. There are many adaptations of these tests with the evaluations of activity in weight or elongation in length of etiolated or green plant sections. Chemical and physical factors play an important part in the stability of indole-S-acetic acid (1AA). The Wisconsin test, apparently, is one of the first tests to use 1AA in a nutrient solution to which other chemicals are added for the evaluation of their toxic preperties to plants. Therefore, very little is known of the compatibility, reactions and res- ponses of plants to Iaa in the presence of many chemicals. Burkholder and Johnston (1937) demonstrated the in- a£=tivation of growth substances by exposure to light. The. ultra-violet region of the Spectrum is very effective in the breakdown of IAA solutions. However, red light has no effect on 1AA solutions. Galston and Hand (1949) demonstrated that auxin-induced growth in length of sub-apical sections of etiolated pea stems 10 was greatly inhibited by light. They report that periods of light as short as one minute or less are effective in caus- ing marned inhibition of growth of etiolated pea sections. These authors report no significant difference of IAA in dark or illuminated pea seedlings. Therefore, they concluded that the disappearance of IAA from solution is not due to plant absorption. EXperiments conducted with 1AA solutions indicate that disappearance of IIA from solutions is depend- ent on the presence of sugar in the medium. The average rate of disappearance of IIA from illuminated solutions is almost double that of unilluminated solutions. Galston and Baker (1949) interpeted this inhibition in the terms of riboflavin sensitized photoinactivation of IAA. 1AA is also destroyed in light in the presence of other inactivators which investiga- tors are now studying. The production of growth by etiolated cuttings deprived of food reserves in its seed requires carbohydrate. The sugar must be applied soon after the auxin treatment (Went, 1937). The Kind of sugar is of considerable importance. The effect of sucrose in the presence of IAA is very interesting because 0f the conflicting reports in the literature. Christiansen and Thimann (1950) claimed that they could find no effect of Sugar on the total growth extension. However, Galston and Hand (1949) observed a considerable increase in the total growth in two percent sucrose although higher Concentrations ll reduced growth. Audus (1953) found tnit final lengths attained by sections in sucrose plus Ina were considerably in excess of those in Ina solutions. One minute contact with Ian may cause great growth stim- ulation (Galston and Hand, 1949). One of the most marred chemical preperties of Inn is its sensitivity to oxidative destruction (Went, 1957). 1AA is stable in alkaline solutions but not in acid solutions (Went, 1937). Avery et a1. (1947) recommends that plant hormone solutions be stored at refrigeration temperatures and should not be used with lime. Audus (1949) has reported the toxicity of very low con- centrations of buffer salts to plants. Casida and allen (1951b) reported that the hydOgen-ion-centration did not significantly alter the growth of the plant in the range of pH 4.0 to 10.0. However, with the phOSphate buffer (KgHPO4 plus KH2P04) a change in the pH distinctly altered the plant growth due to a change in the potassium/phOSphorus balance in the solution. TranSport of IAA is from the apiCal to basal end of the section, and not inversely (Went, 1937). A marked affect upon the activity of growth regulating substances by wetting agents and by some hygrOSCOpic sub- stances thit dissolve growth regulating chemicals has been observed (Zimmerman and hitchcock, 1942). Mitchell and Hamner (1944) claim that polyethylene glycols serve as sol- vents and wetting agents and tend to Keep the growth-modify- ‘ ing substance in close contact with the surface of the plant. 12 Mitchell (1949) stites thtt the uptake of auxins by plants wis greatly influenced by such factors as age of the tissues, temperature, light ahd the presence of surface-active sub- stances which tend to increase the rite ind extend the period of absorption. Hildebrandt (1951) sunmarized the elfects of growth regulating substances on plant tissue cultures. He concluded that the tissue could produce roots, stems and leaves in high concentritions. In low concentrations growth regulating sub— stances favored cambium develOpment and cell division while still higher concentrations stopped cell division and favored cell enlargement or stOpped growth completely. deROpp (1947) observed disorglnized growth in fragments of sunflower stem tissue cultured on agar containing 1 mg. per liter of IAA. The six graphs which follow illustrate the effect of various factors on the growth of etiolated epicotyl sections. The steep slope of the growth curve in time, temperature and concentration of Inn shoss a very sensitive response of plant sections to a small change in the variable. 13 FIG. I. THE EFFECT OF VARIOUS FACTORS ON THE GROWTH or ETIOLATED PEA EPICOTYL SECTionsl P-.__~. - .. O c — m... um , GALITON nun unto—null an mm mm: or mu .0 T I I I” Y I 1 t 1' .. '3 P o r I “mum/section 8 3 U U l 5 5 ,\ I .k.—., I 1 mammal-1m e o o I I Composition of solutions. Figures 4-5. IAA in distilled water. Figure 6. One-microgram of IAA/cc. in distilled water. Eigure 7. One microgram of IAA/cc. and a KH2P04 - NaZHPO4 buffer. 1 Arthur'N. Galston and margery E. Hand, "Studies on the physiology of light action. 1. Auxin and the light inhibition of growth, American Journal 33 Botany 36, p. 89. l4 SIG. II. THE EFFECT OE VARIOUS FACTORS ON THE GROWTH OF EPIOLATED EPICOTYL sEchOhsa “ “’ «AL-vex Al. lent—wax an use" lam-rho): or now?" DI Y “r' x Y Y T v I 1 f r ‘U V ‘ ' ' ' ' ' I I A '- M Mina mom ~w . 1—1 L “ma-rm 3 ; I I .tt . “My ’ ) oennuuose.‘ eifieenL1 on.“ I I v I d .1 A —4 . 4 .. ...........-- lo Composition of solutions. Figure 8. One microgram of Ila/00., 2 per cent sucrose and a pH 6.1 phOSphate buffer. Figure 9. Two per cent sucrose, 6.1 phosphate buffer and 13A as indicated. rhe solid dots a dark cultures; Open dots - light grown cultures. Figure 10 a 11. As indicated. Ibid., p. 91. AlEaRaTUd nhu METHODOLOGY The experiment was carried out in the entomology darkroom. However, there was not enough Space in the darkroom for the incubator so the seeds hid to be tranSported in covered boxes to another room were they were placed in the incubator. A standard method for mixing and applying the toxicant solution Was devised. This was necessary in order to eliminate any variables that might enter into the mixing or spraying of the petri dishes. Apparatus The apparatus consisted of a Spray tank, an electrical stirrer, a 100 m1. graduate and a number of eight m1. gradu- ates. The apparatus was assembled on a ring stand as shown in figure 7. A black cloth was placed over the Spray tank when in Operation to decrease the exposure of the toxicant solu- tion to the yellow safe-light. A yellow light is safe for indole-E-acetic acid solutions (Avery et a1., 1947). All handling Of the nutrient solution prior to its entry into the Spray tank was in amber glassware. The Spray tank consisted of a modified beaker with two double stOpcock outlets on the bottom. To standardize the spray tank the blade of the stirrer was placed two cms. above the bottom of the tank. FIG. III. APPQRATUS. 16 17 The burpose'of each iiece of tne alparatus is exylained in the test Lrecedure. Nutrient éolution The nutrient solution consisted of one-half milligram of indole-S-acetic acid and ten grams of sucrose diluted to one liter with distilled water. _This solution was buffered to a pH of six with M/40 totassium thOSphate buffer. Eor formula- tion, a given volume of each stock solution was added to a volumetric flask (see Tabie 1). Ten grams of file crystalline Sucrose Was then added and the resulting solution diluted to one liter with distilled Water. This nutrient solution was preiared immediately before use. TABLE 1 COMPOSITION OE STOCK SOLUTIONS =:_ Stock Solutions ‘- 1AA K2HPO KHZPO Composition 50 cc. of absolute 40.930 g. '61.648 g. alcohol per liter per liter 50 mg. of IAA enough distilled H20 to make 1 liter CC./liter 1 cc. 10 cc. 50 cc. of nutrient solution grams/liter .5 mg. .409 g. 5.082 g. The indole-E—acetic acid stock solution decomposed in a week or two. Therefore, a new stock solution of the plant 18 hormone had to be made weekly. a brownish tint to the solu- tion indicated that it was inactive. Water from stills containing cotter should not be used in preparing the nutrient solution. The yresence of cotter was found to retard the growth of Plants in this experiment. Test Procedure “ Chemicals tested are listed in Table 4 and the formula- tions tested are listed in Table 4. The DDT used was a technical grade (Special grind) which was manufactured by the Michigan Chemical Corporation of Saint Louis, Michigan. The xylene was a chemically pure grade. All materials were dissolved or dispersed in the nutrient solution at the following rates given as a tercentage of the total weight of the solution or mixture. Eor the surface- active agents alone, the rates used were 0.16p, 0.08%, 0.04fi and 0.02p. The DDT formulations were agglied at the follow- ing percentages of the total weight: 0.9%, 0.45%, 0.22p and 0.11%. The DDT afflications are equal to about two pounds, one pound, one-half pound and one-quarter pound of DDT yer one hundred gallons of water. The test materials were mixed and apilied by the following steps: 1. a knovn weight of the test material was added to the spray tank and then diluted with the nutrient solution to the prober concentration of the tox- icant. (Specific gravities were obtained for all liquid materials and a known volume was added to the spray tank.) 2. The solution was then mixed with the electrical stirrer at a standard rate for two minutes. 3. 9. 19 The toxicant solution was than drawn off at the bottom until only a hundred and fifteen ml. of the toxicant remained in the Spray tank. The solution that Was drawn off went into the 100-ml. graduate for measurement. (Since xylene type emulsions tend to be tOp creamers it was necessary to remove about one-half the sample for the test.) Then five ml. of the toxicant solution was drawn off and added to a petri dish. This procedure was repeated for three petri dishes. After all the petri dishes for one concentra- tion were plated with the toxicant solution 100 ml. of the toxicant solution remained in the tank. One hundred ml. of the nutrient solution was then added to the tank. (The one hundred ml. was previously measured and placed in an amber flask.) Step two Was repeated. Then eighty-five ml. of the toxicant was drawn off into the 100 ml. graduate. Three petri dishes were then plated with five ml. of the toxicant solution. This concentra- tion was one-half the first concentration. Steps six, seven and eight were repeated until the desired number of concentrations were ob- tained. Cucumber seeds of the National Pickling variety from a standard lot were immersed in water for one hour then germin- ated between wet paper towels in covered petri dishes for twenty-four hours. After the incubation period seeds which had sprouted one or two ml. were selected for treatment in the darkroom under a yellow safe-light. Eifteen seeds were placed in each petri dish and three petri dishes were used for each concentration. The petri 23 dishes with a filter paper on the bottom were previously treated with toxicant solution or emulsion. The seeds in covered petri dishes were then incubated at twenty-six degrees centigrade for thirty-six hours. After the incubation period the seeds were removed from the incuba- tor and placed in the refrigerator at four degrees centigrade until measured. All seeds were measured within four days of treatment. The eValuations of the toxic action was based on inhibition of growth in length and in weight. The entire seedling was measured from the tip of the root to the point of attachment of the cotyledons. The weights were based on the wet weight of the roots when out off at the cotyledons. Evaluations of toxicity were made by the phytotoxic index. The formula for this index is: ( control - treatment_l X 103. control Although no evaluations of the test materials on the Kentucky'flonder pole bean are made in this report the method was tried and is treated in the discussion of the Hisconsin test. The procedure for this method follows. A uniform standard lot of bean seeds were immersed in water for one hour and planted in moist vermiculite in dark- ness. The plants were grown at room temperature. Seven-day- old plants from which the epicotyl had not yet emerged and which ranged from ten to twenty cm. were selected for testing. A twenty-mm. section was removed from the hypocotyl of each plant beginning at a point one cm. below flue node at which the 21 cotyledons were attached. The cutter consisted of two rows of razor blades mounted twenty mm. apart on a handle. The handle was attached by a hinge to a cutting board. The plants were placed on this board and the handle was moved down to out the stems. The stem sections were placed on a watch glass with one end towards the center and the other towards the rim. Eif- teen stems were placed on each watch glass. The watch glasses were than placed in the petri dishes. At this point the tox- icant solution or emulsion was applied to the center of the watch glass. The petri dishes were than placed in the incu- bator and the sections allowed to grow for thirty-six hours and then measured by the shadow graphs. The nutrient solution and the method of mixture was the same for both tests.. materials and Formulations LDT EJULSIEIABLE CONCENThaTES paste 2 EO RMU LAT ED AND TESTED 22 Percent officoncentrate Emulsifier A ' % DDT Xylene % emulsifier Aerosol OT 25 72 3 Emcol H-77 25 72 3 Santomerse D 25 73 2 ‘ Areskap 25 71 4 Polyethylene 25 71 4 Glycol 400 Toximul 500* 25 71 4 Toximul 400* 25 69 6 Triton X-100* 25 72 4 Triton X-l50 plus 25 71 2 Triton X-160* 1 Triton X-l55* 25 7O 4 Triton X-155 plus 25 70 2 Triton B-l956 5 *Formulated as recommended by the manufacturer. r" \ ff“ w/ ”av Adv any any .nvn! make nlpullfl ‘.I-I.A ..l-v_l. .oo mwmm a 820m .00 mmmz w snow wnfipagwpommq HOGHz meHLOpwsonmq Homwz .oo mpozeoam oohao .oo muosnopm oomao .oa meezezaa eeaao .oo .Emno OpCmmcox .oo .Emso cpaemcoz .mpoo HOmHSEm .oo UHEdsmho .moapefiq .co @flfiocmho smeath< w‘l‘I-II‘JI- ltt’bllt hamafiou Ill wepwsowHSm unstHo spa; aaosooam penumhaoq Hana Hmaam Honooaa amngmhaom ahpa Haida was: an Umpwowncfl mm camcomazmocoe Edwuom Hocozqahcezm Hzpmhocoe oposomasw Edwvom ampm amaaw wood mHHo ampwcomazm Una mamwmw oflmmxonmmo Hosooawhaoa mo fines; 4 to.eOeOOeloOOIDOOOOOO mpwcfioosmomazm empoofie adaeom cowpflmomEoo Heewsmgo mmHmHmJDEm mo Hmwa Qz< wombom .oneHmomEOU m m4m49 emanx engage ooa-x sewage mos assaxee oom aseere nomanm mmaalm eeeazea nozsav oo.V Hoohao ocmahngmzaom Om mmxmmp< '1) 4 v.4 I) ‘ _ Q .14 ( a»: EU 03 whim Hooem mmm PO HDmOhmwd. penaamaaem mannaomcH poem: and oflcoflnco: Ava oaszaoacm hope: one ofiQOflcw a. x . a e mansaom amps; new oa:ofilsoc Amv mansaom :eae; 32s osmoacm Adv .oo ussoaoz Amv mo acom :a .H .m mwsmamc «mmao s:HUOm mawmpcoo ucom 5Q mnflaoqhoflo ocefihsam :a gamma 3,. 3% e seem use? 3323 8333 e .8 E. 2.31m goers. Leaflaflnmpw sowmadsm mm spa: “my uses 2 Snom mfiogooam nonmem~oa Aha: tham mwatx cepflnh awesome amcw m use hepflnfisdfl defla0haoc «momfimflnmaa :oflmwssm gwfl; swamp chads Hopmomam oaamzpza Umfluacofi m use “ma m‘em a smom sonooam poz+ehaom Hana Hagan branx sewage wmpmcowwzw oflawmho npflz mwmm # Each aoLCOHa pwzwchaoa H%hm Hagan Ocatx nonwha 5 3% e 22 sage: he 3% ace 3: a; use; mama hgmasou :oflefimoafioo anomaono sewgflmaznw .ac00 m m4m \ . . \\ Pfihe phytotoxio index is based on length measurements. '70 ~90 _L__.__'_ ' J 0.11p" 0.22p 0.45; 0. Concentration. 9w G. U FIG. IX. THE EHYTJEOKICITY OE DDT FORLULATIONS 30 DECEMBER FLARTS A ()1 120 110 100 90 80 70 60 50 4O 30 F— M; The pyfotoxic index is based on weight meosureme h; A e50 0.11; O o 22,.) ‘0.45fi Concentration. .‘io—f .Jgéj 111 .'. Y) n ~ ‘L .- ¢.\% .. V Udttt. 4. (A J ‘4 IN FIG. XI. TOXIJUL 400. Per cent of emulsifier in nutrient ' solution was .08 per cent. FIG. XII. LL”)? 85,0, 11731713 71;; Jilin ItiII'UI‘. 37- 100. EIG. XIII. DDT 25¢, XYLENE 71p AND TRITON X-lOO. Per cent of concentrate in nutrient solution was 0.9 per cent. =1" L1 EIG. XIV. AEROSOS OT. FIG. XV. AEROSOL OT. Per cent of emulsifier in nutrient solution was 0.16 per cent. 34 ‘Jll|v. I v . DIdCUsSION Emulsifiers The emulsifiers were tested separately to determine their specific toxicity to the test plant. As indicated by the summary graphs a wide range of toxicity Was found. aerosol.OT and BPE of the American Cyanamid Company were found to be the most toxic materials tested. However, they were not the most toxic emulsifier at every concentration. Santomerse D was the most toxic material at the 0.9% concen- tration, second in toxicity at the 0.45% concentration, third at the 0.82% concentration and at the lowest concentration non-toxic. as indicated above, the concentration of the emulsifier is critical in determining the degree of toxicity of a material in relation to the other materials tested. This is due to a difference in the SlOpeS of the toxicity curves of the dif— ferent chemicals tested. The $10pe of the toxicity.curve was not the same between each concentration but tended to decrease as the concentration increased. When grouped according to their type and water solubility the anionic emulsifiers were in general more toxic. Eor a given type of emulsifier the water soluble compounds were found to be the more toxic. Among the water-insoluble chemicals the water-miscible chemicals were most toxic. The four groups |\.I|||a/II-|.I1./ Ill. .Jrltnlu‘l/I‘li‘l/IIIII‘./{L|. 56 of emulsifiers are given below in the order of their general phytotoxicity rating. The rating is: over 49.5%.......very toxic over 25.5w.......toxic over 9.5%.......slightly toxic under 9.5%.......non toxic. Eor the 0.16% concentration the rating is as follows: 1. Anionic-water-soluble group.......very toxic 2. anionic-water-insoluble group.....toxic 3. Non-ionic-water-soluble group.....slightly toxic 4. Non-ionic-water-insoluble group...non toxic. The groups tended to have a lower phytotoxicity rating with a decrease in concentration. The anionic-water-soluble group was very toxic at the 0.08fi concentration, toxic at the 0-04W concentration and non toxic at the 0.02% concentra- tion. However, one member of this group, aerosol OT, could be considered very toxic at every concentration tested. The anionic-water-insoluble group was slightly toxic at the 0.08% concentration and non-toxic at the two lower concentrations. Grasselli Spreader-sticker, an anionic water insoluble material, was slightly toxic at the 0.16m concentration and non-toxic at the other concentrations tested. The non-ionic water-soluble group was slightly toxic at all concentrations tested. Several of the chemicals in this group tended to be relatively non-toxic at the lower concen- trations. The non-ionic water-insoluble compounds were non- toxic at all concentrations tested. The stimulation in growth might be explained by the increased wetting and the longer contact of IAA with plant surfaces. .y ‘1... riafi .. Wu.“ 37 A wide range of toxicity was found for chemicals within the same group. Considerable overlapping occurred between the anionic water-insoluble group and the non-ionic water- soluble group. This was due to the very low toxicity of Grasselli Spreader—Sticker. The relative phytotoxicity of the four groups is based on the emulsifiers actually tested. It is possible that tests of additional emulsifiers of the four groups could alter the ratings given in this paper. DDT Eormulations As indicated by the graphs of the results a wide range of toxicity was found. The DDT formulations containing anionic emulsifiers were usually more toxic then the formulations containing non-ionic emulsifiers. The toxicity of the form- ulations at the lower concentrations depended on the stability of the emulsion, a stable emulsion giving the maximum amount of toxicant on the petri dish. The Aerosol OT formulation was found to be the most toxic enntlsion tested at the highest concentration. It was slightly toxic at the 0.45% and 0.22% concentrations and non-toxic at the lowest concentration. Toximul 400 was second in toxicity at the highest con- centxmition but most toxic at the two lowest concentrations. Thi¢3:formulation could be considered toxic~to slightly toxic ovez7'the concentration range tested. It contained six percent ennghsifier which was twiCe the amount used in the Aerosol OT 58 formulation. Both the above emulsifiers were of the anionic type. The most toxic non-ionic emulsifier was Triton X-lOO. The Triton X-100 formulation rates third in toxicity. Triton X-100 and Toximul 400 were the only emulsions that were toxic in both weight and length relationships at all concentrations tested. Plants treated with Emcol H-77 and Areshap 50 were in- hibited by ten percent or more in length only at all concen- trations. The weights of plants treated with Emcol H-77 and Areskap 50 were not altered significantly. Generally the treated plants were found to have a higher phytotoxicity index in length evaluations. However, there were exceptions. The Triton X-155 plus Triton B-l956 and the Triton X-155 emulsions showed a higher phytotoxic indices in weight. Plants treated with Aerosol OT and Emcol H-77 followed the same pattern at the 0.22% concentration. The wetting ability of the emulsifier or the DDT formula- tion could influence the weight evaluations to a great extent. Evaluation gf Method The fundamental purpose of phytotoxicity studies is to determine the effect of agricultural Sprays on host plants. This research is divided into two types - field studies and laboratory investigations. The objective of the laboratory screen test should be to provide a sound basis for field stud- ies. Therefore, there should be no sharp differences between 59 3 the two types of research and the two should be complementary. The absence of chlorophyll and photosynthesis in the test method and the absence of indole-b-acetic acid in most field tests provides a sharp contrast between this laboratory test and the field test. Reactions between the nutrient solution and the toxi- cant provide a large number of unhnown and uncontrollable factors which influence in various ways and degrees the re- sults of the experiment. Both antagonisms and synergisms are xnown for indole-E-acetic acid in the split-pea test and the pea elongation test. Thus conclusions arrived at in this experiment are lacning in accuracy and may be entirely wrong. The test is a very sensitive one. The presence of light other than those indicated in the literature review inacti- vates the nutrient solution. The tolerance for many varia- bles is very low. For instance, a difference of a few de- grees in temperature may alter the growth of the plants to a great extent. also the length of time that a plant is ex- posed to the indole-S-acetic acid will determine the amount of growth resulting from a given eXperiment. This factor varies greatly with each test and each concentration within a test. Therefore, the author believes that all plant ma- terial should be treated for a given length of time in a "common growth-promoting solution and then transferred to the toxicant solution. This would eliminate any inactivation of the indole-S-acetic acid and prevent many antagonisms and synergisms possible under the test method used. 40 the results cannot be extended to any conditions other than those of the test. The growth relationships were found to differ from those reported by Yilson and dleesman (lvéb) for field tests of forty varieties of cucumbers. Ihey.found that the stunting of the plants progressed in a straight line relationship with each successive doubling of the quan- tity of the toxicant. Only one material showed a straight line relationship by the test method. I another problem is the standardization of plant mater- ial. a very careful selection of plant material is necessary to lower the variability of plant growth results. Several test concentrations were picked at random and a standard deviation was calculated. ihe standard deviation averaged about twenty percent of the mean. Ehe fact that indole-B-acetic acid solution may under certain conditions produce morphological changes, extensive growth or inhibition of growth limits this method as a test for the evaluation of chemicals for agricultural Sprays. oxidizing agents and lime cannot be used as test mater- ials in this test for they tend to inactivate the auxin. For the aerial test growth results depend largely on the length of time the plant hormone remains active in the solution. A few seconds difference in the life of the hor- mone will cause great differences in plant growth. Galston and Hand (1949) report that one minute contact with tax will cause great growth stimulation. 41 The transportability of the test chemical within the plant may alter the aerial test unless the entire stem sec- tion is exposed to the toxicant solution. although the author in the above discussion has ob- jected to this method of evaluating insecticidal phytotox- icity it is nevertheless approved by many biolOgists. The following quotation is from a letter the author received from Arthur W. Galston, Associate Professor, California Institute of Technology: "I have read the article of Casida and Allen, and see no major objections to the method they use. It is possible, by the use of some re- finements, to reduce the test to a 4-6 hour assay. This is better, not only from the point of view of convenience but also because it obviates errors due to microbial effects. Nevertheless, I consider these objections not to invalidate the method used." Eighteen emulsifiers were tested for their toxicity to the National richling cucumber. When grouped according to their type and water solubility the following rela- tionship was found for each group: anionic water-soluble group.......very toxic anionic water-insoluble group.....toxic non-ionic water-soluble group.....slightly toxic non-ionic water—insoluble group...non-tcxic. The above grouping indicates the toxicity of each group as a whole. Tmulsifiers within a group tended to vary greatly. Several emulsifiers were more or less toxic than the rating given the group to‘which it belongs. 4 wide range of phytotoxicity was noted for eleven bDT emulsions. The only variable in each formulation was the emulsifier which varied from two to six percent of the concentrate. lhe formulations with the anionic emulsifiers were generally more toxic than the formula- tions with the non-ionic emulsifiers. Generally water- soluble compounds were more toxic than water-insoluble compounds. The test was found to be very sensitive to a number of variables. standard conditions have been defined and must be carefully followed. synergisms and antagonisms caused by the toxicant in the nutrient solution may lead to faulty conclusions. 43 The fact that the sensitivity and growth regulating prOperties of indole—S-acetic acid is not clearly under- stood limits this test method. Plant responses to the indole-E-acetic acid may lead to the production of roots, excessive cell elongation or inhibition of growth which would alter measurements and conclusions. a sharp division between the laboratory and field con- ditions exist. This is due to the absence of chloro-' phyll and photosynthesis in the laboratory test. An evaluation of the results cannot be extended to any conditions other than those actually tested. p. LITERATURE CITED Allen, ’1‘. C. and J. E. Casida ' 1951. Criteria for evaluating insecticidal phytotoxicity - Aerial growth. Jour. Econ. Ent. 44(5): 58-741. Audus, L. J. 1949. Studies on the pH relationship of root growth and its inhibition by 2,4-dichlor0phenoxacetic acid and coumarin. New Phytol. 48: 97. dudus, L. J. 1952. The time factor in studies of growth inhibition of excised organ sections. Jour. Exptl. Bot. 5(9): 275-592. Avery, George S. and Elizabeth B. Johnson 1947. Hormones and Horticulture. New York: McGraw Hill Book Company, 526 pp. Beal. ..M. and Geraldine‘fihiting 1945. Effect of indoleacetic acid in inhibiting stem abcission in Mirabilis jalgp_. Bot. Gaz. 106: 420- 451. Ben-Amotz, Y. and W. M. Hoskins 1957. Factors concerned in the deposit of sprays. III. Effects of wetting and emulsifying powers of Spread- ers. Jour. Econ. But. 50: 879-886. Blackman, G. E. 1952. Studies in the principles of phytotoxicity. 1. The assesment of relative toxicity. Jour. Exptl. Bot. 5(7): 1- 27. BrO'Nn, A. ‘5'. LL. 1951. 'Insect Control by Chemicals. New York: John Wiley.& SOUS, Ina. 817 Pp. Brown, G. T. and '3. M. Hoskins 1959. Factors concerned in the deposit of Sprays. V. The effects of pH upon the deposit of oil and water phases of oil emulsions. Jour. Econ. Ent. 52(1): 7-61. Burkholder, P. R. and F.. S. Johnston 195 7. Inactivation of plant growth substances by light. Smithsonian hisc. Collection. 95(20): 57—61. 45 Casida,J. E. and T. C. Allen 1951a. A laboratory method for evaluating the ph totoxicity or phytostimulation of insecticides. Science. 115 (2941); 53-5550 Casida, J. E. and T. C. Allen 1951b. Criteria for evaluating insecticidal phytotoxicity - Root growth. Jour. Econ Ent. 44(5): 741-746. Chapman, R. K. and T. C. Allen 1948. Stimulation and suppression of some vegetable plants by DDT. Jour. Econ. Eat. 41(4): 616-625. Christiansen, G. S. and K. V. Thimann 1950 The metabolism of stem tissue during growth and its inhibition. 1. Carbohydrates. Arch. Biochem. 26: 248-259. Cullinan, E. P. 1949. Some new insecticides their effect on plants and soil. Jour. Econ. Ent. 42: 587-591. DUdley, J. 3., Jr. 1947. Phytotoxicity of DDT dusts and sprays to truck crops in Wisconsin. Perliminary observations. U. S. Dept; Agri. Tash., Bureau oftEntomology and Plant Quaran- tine Bull. E-715. Ebeling, Walter 1959. The role of surface tension and contact angle in the performance of spray liquids. Eilgardia 12(11): 665-698. Galston, Arthur W. and Margery E. Band 1949. Studies on the physiology of light action. 1. Auxin and the inhibition of growth. Amer. Jour. Bot. 56: 85-94. Galston, Arthur T. and Rosamond S. Baker 1951. Studies on the physiology of light action. IY. Enhancement of auxin induced growth in green peas. Plant Physiology 26(2) 511- 517. Galston, Arthur w. 1955. Letter to author. Gunther, B‘. A., D. L. Lindren, m. I. Elliot and J. P. LaDue 1946. Persistence of certain DDT deposits under field conditions. Jour. Econ. Ent. 59(5): 624-627. Hervey, G. E. R. and W. T. Schroeder 1946. The varietal reSponse of cucumbers to DDT control. Jour. Econ. Ent. 59: 405-404. 46_ Hildebrandt, Albert C. 1951. In vitro experiments on tissues of pathJIOgical orgin. Skoog, folks Ed. P ant Growth Substances. Symposium, University of -isconsin Press 476 pp. Lindquist, a. w., H. 1. Jones and 1. H. madden 1946. DDT residual-type Sprays as effected by light. Jour. BOON. Ento 59(1): 55-590 Lumsden, David V. and Floyd F. Smith 1948. Growth responses of halanchoes to DDT and other synthetic compounds. Proc. Amer. Soc. Hort. 51: 618-622. Magie, R. 0. 1947. IDT injuries gladiolus florets. Gladiolus Mag. 11 (6): 11-12. Merrill, Leland Gilbert, Jr. _ , 1949. A study of the effect of the application of DDT on the physiology of the peach seedling, Prunus persica L. and a study of the effect of the application of' DDT to the host plant on the reproduction of the two-spotted mite Tetranychus bimaculatus Harvey. Unpublished Ph. D. ihesis, Rutgers Univ., New Brunswick, New Jersey. 108 pp. Mitchell, J. T. and C. L. Hamner 1944. Polyethylene glycols as carriers for growth regu- lating substances. Bot. Gaz. 105: 474-485. Mitchell, J. N. 1951. Translocation of growth-regulating substances and their effect on tissue composition. Skook, Folke Ed. Piant Growth Sunstances. Symposium, University of Wisconsin Press 476 pp. de ROpp, R. S. 1947. The growth-promoting and tumefacient factdrs of bacteria-free crown-gall tumor tissue. Amer. Jour. Bot. 54: 248-260. Sisley, J. P. translated by P. J. Wood 1952. Encyclopedia of surface-active agents. New York: Chemical Publishing Co., Inc. 540 pp. Went, F. We and K. V. Thimann 1957. Phytohormones. New York: MacMillan Co. 294 pp. 47 Wester, R. c. and c. A. Weigel 1949. Effect of DDT and wetting agent on the plant growth of Triumph and Peerless varieties of bush lima beans. Proc. Amer. Soc. Hort. Sci. 54: 373-377. 'Nilson, J. D. and J. P. Sleesman 1948. Pesticides - A study of their effects on the growth and transpiration of cucumber, tomato, and potato plants. Ohio Agri. Exp. Sta. Bull. 676. Zimmerman, P. W. and A. B. Hitchcock . 1942. Substituted phenoxyaand benzoic acid growth sub- stances and the relation of structure to physiog- ical activity. Contri. Boyce Thompson Inst. 12: 521-343. APPENDIX I. Emulsifier Measurements in Grams and Millimeters. II. DDT Formulation Measurements in Grams and in Hillimeters. Length Tables 1. Numbers in tne columns below each concentration represent the length of a single plant in millimeters. ‘ 2. The numbers in the brackets represent the total growth of 'all plants in one petri dish in millimeters. 5. The line labled Tot. gives the total growth in millimeters for each concentration. ' 4. The line labled P. I. gives the phytotoxic index for each concentration. Percentage of concentration of material in nutreent solu- 01 0 tion was by weight. 49 Table 4 PHYTOTOXIC INDEX AND WEIGHTS IN GRAMS OF CUCUHBER PLANTS Percentage of concentrate in nutrient solution Emulsifier . i , Control 0.16% 0.08%_ 0.04% 0.02% Aerosol OT 1.665 (p202 {p210 (*360 1.344 g. BPE 2.360 0.630 0.710 1.274 1.820 73.3% 69.9% 46.0% 22.9% Emcol H-77 2.040 1.648 1.805 2.100 2.120 19 .270 1105/0 -209?) -4 0230 Santomerse D 1.780 0.415 0.735 1.221 1.626 76.7% 58.7% 31.4% 8.7% Areskap 50 2.040 1.159 1.372 1.581 1.840 43.2}0 520870 22.5% 90870 Polyethylene 1.240 1.410 1.315 1.280 1.475 Glycol 400 -13.7% -6.0% -3.2% -19.0% 8-1132 1.780 1.552 1.720 1.819 1.630 12.8% 3.4% -2.2% 8.4% 3-1207 1.630 0.861 1.205 1.327 1.705 47.2% 26.1% 18.6% -4.6 Toximul 300 1.427 0.860 1.238 1.515 1.405 39.7% 13.2% -6.2%» 1.5% Toximul 400 1.427 0.984 1.452 1.415 1.475 31.0% 0.1% 0.8% -3.4% Triton 2-100 1.620 0.870 0.925 1.385 1.278 46.3% 42.9% 14.5% 21.r% Triton X-150 1.710 0.690 0.840 1.045 ..... 59.6% 50.9% 38.8% ..... TABLE 4 CONT. 50 Percentage ofVconcentrate in '— nutrient solution Emulsifier , , Control 0.163 0.08% 0.04% 0.02%L Triton x-155 1.620 .336 1.414 1.600 1.437 g, 17.5% 12.7% '1.2% 11.3% p. I. ’ 49 0 76/0 35 00% 30 04‘20 e e 0 Triton 1-177 1.475 1.315 1.505 1.610 1.530 lOQBJP -2007‘0 -902?) “3.7%? Triton X-188 1.475 0.925 1.310 1.410 1.485 Triton B-1956 1.240 1.475. 1.570, 1.411, 1.320 -19.0% -26.6% -13.8% -6.5% Du Pont Spreader 1.665 1.475. .1.745 1.765 1.965 Sticker 11.4% -4.8% -6.0% -18.0% Each figure represents the weight and phytotoxic index for forty five plants. Illa! Iii-Ill]: .1 [II - ,,,,,,,,, 51 Table 5. Aerosol OT Percentage of emulsifier in nutrient solution Control . , , 28 2 3 5 22 47 3 4 6 4 47 4 3 2 7 28 3 3 5 22 29 3 4 5 8 31 2 3 6 10 30 3 4 3 19 47 3 4 3 10 26 5 4 3 24 53 4 4 4 ll 17 3 14 2 7 31 4 3 4 21 26 4 3 6 22 23 5 2 2 23 14 (477) ‘ 4 ( 52) 3 ( 61) 3 ( 59) 25 (235) 38 2 3 4 25 29 3 2 2 9 , 44 2 2 2 26 26 2 3 3 26 51 4 1 3 9 38 4 2 2 8 36 2 2 5 13 43 4 3 3 13 38 3 4 3 8 31 2 3 6 18 47 5 3 5 19 33 2 2 6 20 12 4 2 3 8 31 3 1 ' 2 25 36 (533) 4 ( 46) 2 ( 35) 6 ( 55) 12 (239) 26 5 3 2 30 49 3 3 5 19 46 3 3 2 20 31 3 3 2 -28 27 2 3 3 24 31 3 3 3 27 42 4 3 6 16 12 3 3 7 21 35 2 2 6 18 31 2 4 3 25 24 3 2 6 8 28 2 3 4 22 28 4 4 6 20 29 3 5 4 21 *gg 4 (443) 2 ( 44) 2 ( 46) 5 ( 64) 12 (311) Tot. 1453 142 142 178 785 P. I. 90.3% 90.3% 87.8% 46.0% .“ A " «aun‘uii Table 6. BPE Percentage of enulsifiier in nutrient solution Control , _ . , 0.16% 0.08% 0.04% 0.02% 46 8 11 18 46 60 6 7 23 34 65 7 8 ' 35 42 65 11 23 19 21 46 7 12 28 53 65 9 16 28 4Q 39 4 8 28 44 61 6 13 21 46 53 8 11 26 20 58 12 11 24 26 64 10 10 26 44 35 13 26 12 46 54 9 17 29 50 55 9 16 37 43 (809) 2 (121) 8 (197) 30 (376) 21 (570) 58 7 3O 2O 40 39 6 33 19 41 34 10 28 14 3 54 9 3O 21 3 65 11 26 21 42 62 7 38 19 27 58 7 11 34 33 60 8 13 18 33 34 5 18 21 41 33 9 7 16 32 8 5 31 21 40 58 3 31 7 3 66 3 21 6 37 49 3 13 25 32 71 (749) 6 ( 99) 13 (343) 22 (284) 36 (535) 35 6 14 28 55 33 6 3 22 35 38 6 14 37 49 24 6 11 17 51 37 8 11 23 43 6O 8 ll 22 .6 44 5 20 22 44 38 5 10 16 22 27 4 15 25 33 50 7 .9 22 33 40 ll 16 36 18 26 10 12 21 26 39 9 11 20 51 38 8 30 5O 36 ___10 (539) 4 (103) 13 (210) 2 (363) 32 (584) Tot. 2097 323— 750 1023 1689 _g. I. 85.6% 64,2% 51.2% 19:32, 37.) (4,.) - ,II-: Jililll. JIlnfi. 53 U . Table 7. Toximul 300 Percentage of emulsifier in nutrient solution Control , , . 43 10 35 2O 48 36 4 3O 18 35 37 12 28 13 21 37 12 39 29 44 34 11 30 40 37 32 11 22 3O 31 30 24 25 30 26 28 17 24 27 5O 29 14 18 35 31 33 12 19 33 53 32 10 28 46 51 33 ll 33 26 40 3O 6 14 41 48 4 31 21 28 39 24 (462) 14 (199) 11 (377) 44 (460) 42 (596) 48 14 . 25 30 48 52 10 29 44 25 25 9 27 34 2o 31 9 33 29 29 38 6_ 24 46 23 26 9 25 39 45 4 7 27 29 24 28 11 36 32- 6 26 7 30 28 35 21 5 22 41 53 33 7 15 28 44 20 11 19 30 56 36 19 15 25 26 29 3 34 24 23 44 (502) 13 (140) 27 (388) 30 (489) 51 (514) 51 3 28 29 23 37 16 27 26 17 39 19 30 _ 44 52 24 19 26 39 24 57 17 21 43 23 24 19 25 4O 22 52 9 3 39 22 27 4 26 10 35 3O 10 18 48 29 3O 5 17 34 28 36 4 27 32 27 39 2 25 2O 13 23 7 15 39 16 3O 9 8 36 36 ___29 (528) 11 (154) 20 (347) 39 (518) 34 (381) Tot. '1492 493 1112 1467 1491 P. I. 67.0% 25.5% 1.7% .07% 54 Table 8. Toximul 400 Percentage of emulsifier in nutrient solution Control , , , , 0.16% 0.08% 0.04% 0.02% 43 22 48 45 26 36 27 23 37 42 37 20 40 33 45 37 19 39 38 32 34 17 41 25 20 32 26 30 41 23 30 17 24 24 26 28 29 41 45 57 29 27 43 28 34 33 3O 40 45 23 32 23 4O 40 42 33 24 28 29 44 30 28 23 32 32 4 12 33 16 44 24 (462) 16 (337) 27 (520) 3 (481) 36 (526) 48 30 41 26 38 52 31 . 33 17 30 25 23 42 40 44 31 28 34 36 33 38 24 39 22 46 26 21 27 39 29 45 29 39 35 43 28 33 23 22 22 26 24 39 33 36 21 26 18 32 33 33 23 40 46 63 20 22 33 37 30 36 18 42 43 33 29 5 38 4O 38 44 (502) 14 (351) 3 (491) 20 (488) 33 (551) 51 29 39 34 45 37 16 41 35 33 39 20 _ 40 38 45 24 13 38 ' 32 30 57 20 42 43 20 24 16 21 ‘29 38 52 19 4O , 36 35 27 16 36 41 35 3O 13 33 30 34 30 3O 24 37 29 36 10 43 34 19 39 9 8 37 37 23 7 3O 46 30 30 6 33 4 33 29 (528) 15 (239) 33, (501) 34 (510) 35 (498) Tot. 1492’ 927 1512 1479 _1575 P. I. 370% “10% 09% ‘50% 55 Table 9. Santomerse D Percentage of emulsifier in nutrient solution Control , , 4 0.16% 0.08% 0.04% 0.02% 19 .2 7 37 21 30 6 5 35 35 24 3- 2 23 40 44 3 6 20 39 54 2 6 31 40 26 4 21 23 53 44 2 2 27 45 40 5 14 26 5 22 2 8 33 6 45 3 7 45 21 23 5 6 29 39 34 4 4 28 29 57 4 5 28 32 23 2 4 43 36 52 (537) 2 ( 49) 3 (100) 44 (472) 17 (458) 33 4 8 25 46 35 3 7 4o 25 27 5 7 19 42 31 4 12 28 43 49 4 4 32 21 37 5 3 38 37 49 4 5 31 49 8 3 5 25 35 27 3 2 45 41 37 2 7 20 46 31 4 13 34 49 29 2 7 39 45 35 2 5 3 28 29 q 2 8 19 37 42 (499) 2 ( 49) 10 (103) 31 (429) 44 (588) 51 4 9 25 45 51 3 16 32 19 48 G 5 53 29 31 2 3 26 25 30 3 3 13 35 42 4 13 17 44 47 5 3 31 37 27 3 3 29 69 50 3 1 3 10 42 31 2 4 4 31 36 5 4 26 33 37 4 2 23 39 12 2 6 33 42 24 2 12 21 35 19 (536) 2 ( 50) 2 ( 88) 9 (352) 17 (542) rot: I572 148 291 . 1253 1588 r. I. 90.6% 81.5% 20.3% .1.0% 56 Table 10. lreskap 50 Percentage of emulsifier in nutrient solution Control , ' A , 0.162 0.08p 0.04; 0.02; 59 36 32 39 39 55 12 33 . 48 57 44 19 34 55 21 47 17 27 36 49 34 ,19 29 33 70 53 10 27 28 57 35 12 42 50 37 60 14 19 8 67 48 14 32 43 31 47 13 38 53 36 21 5 24 57 67 45 16 37 55 82 52 23 23 48 29 20 ll 24 42 22 25 (645) 18 (239) 17 (438) 25 (620) 12 (676) 33 40 31 3o 21 33 30 32 47 52 36 6 24 39 37 30 7 31 23 45 53 28 39 39 30 34 20_ 36 31 52 56 6 28 19 53 64 26 . 35 5 34 41 3 21 - 56 19 36 9 15 30 17 39 7 15 43 51 33 11 32 46 32 28 15 30 47 55 22 9 21 38 - 18 79 (617) 15 (232) 13 (403) 62 (555) 17 (533) 33 11 46 50 65 31 11 31 23 24 58 16 30 45 73 38 3 25 9 49 47 7 32 49 36 32 9 24 41 61 27 15 21 42 64 61 14 12 37 56 44 2 37 34 66 41 16 21 35 46 38 16 28 36 36 40 6 8 45 69 23 10 20 5 33 33 11 20 25 32 16 (562) 13 (160) 31 (386) 47 (525) 17 (727) Tot. 1824 631 1227 1700 1936 _g. 1. 65.4% 32.74 6.8% -6.1% Polyethylene Glycol 57 Table 11. 400 (Mono) Laurate Percentage of emulsifier in nutrient solution Control , _ . y 35 25 25 29 37 28 22 24 27 9 23 31 33 38 4O 25 22 36 18 29 31 39 31 21 31 26 33 36 34 3O 16 33 15 49 46 24 3O 41 13 3O 39 ll 51 34 29 27 31 23 35 35 36 32 4O 3O 32 33 21 24 4 3 28 3O 29 3 41 24 25 25 36 37 8 (403) 36 (421) 15 (448) 15 (386) 11 (470) 30 39‘ 24 27 3O 44 37 33 35 39 39 26 25 33 25 32 9 34 26 34 31 2O 33 29 23 29 42 22 30 4 39 42 54 29 24 19 52 45 45 35 26 7 34 17 22 18 36 31 23 33 3O 48 26 4O 29 24 3O 35 25 27 29 35 38 3O 25 14 38 28 ll 6 13 (417) 29 (490) 10 (472) 18 (418) 4 (36C) 41 10 29 23 35 3O 29 25 _ 2O 14 35 26 16 45 42 24 16 8 41 21 31 7 22 35 24 21 21 35 3O 38 3O 35 29 24 25 2O 29 28 43 16 27 29 39 17 37 28 39 2O 23 8 28 29 39 18 38 45 29 33 22 35 34 33 34 34 45 20 33 21 34 43 3 (417) 20 (385) 32 (410) 11 (420) 27 (448) Tot. 21237 1296 1338 '1224 #12787 _g. I. -4.8% -7.5% 1.1% -3.3 58 35616 12. 8-1132 Percentage of emulsifier in nutrient solution Control 7 _ 0 . 16% 0 . 08% 0 . 04% 0.02% 19 25 27 42 32 30 27 27 41 26 24 47 36 47 32 44 45 43 62 29 54 35 42 42 39 26 46 30 7 21 44 61 22 51 32 40 58 39 54 28 22 50 6 59 .38 45 56 30 63 37 23 28 37 24 41 34 23 31. 37 34 57 25 34 22 52 23 17 60 24 31 52 (537) 5 (548) 35 (499) 38 (613) 35 (507) 33 25 43 36 25 35 20 22 45 25 27 34 45 47 25 31 58 31 34 28 49 35 46 44 51 37~ 31 48 30 38 . 49 23 3 32 30 8 18 28 41 26 27 37 20 '36 20 37 29 2 45 46 31 34 46 42 21 29 25 50 43 18 35 33 41 28 19 29 51 29 4 2 42 (499) 47 (500) 32 (486) 2 (509) 3 (377) 51 4 30 41 30 51 36 29 39 51 48 32 41 38 45 31 35 41 36 48 30 55 31 48 53 42 42 45 21 45 47 44 66 43 33 27 39 40 37 11 50 44 35 38 55 31 41 43 41 29 36 43 55 45 30 37 33 40 28 30 12 53 31 49 35 24 46 40 53 24 _ 19 (536) 56 (603) 45 (615) 26 (581) 14 (533) Tot. 1572* ‘1651 1606 1703' 1417 P. I. -5.0% -1.8% -8.3% 9.9% 59 Table 13. 6-1207 Percentage of emulsifier in nutrient solution Control . . 0.16% 0.08% 0.04% 0.02% 33 52 33 28 27 37 53 36 51 53 26 33 42 10 35 54 31 32 4O 23 34 33 44 3O 39 66 2O 4 46 27 11 4 32 38 47 38 7 10 57 37 4O 22 35 28 43 25 2 41 28 54 34 5O 40 54 51 36 38 4O 2 4O 10 2 32 3 65 20 8 3 8 35 13 (477) 2 (357) 2 (426) 10 (433) 3 (579) 30 8 34 44 15 43 3 52 43 31 22 6 45 57 39 29 24 13 31 51 28 39 32 31 51 38 46 3O 42 16 27 49 46 27. 25 46 49 5O 38 55 6O 31 63 3O 39 43 51 63 53 49 39 3 . 3 11 43 38 21 ll 17 40 35 13 34 22 18 3O 4 5O 52 36 29 (537) 25 (404) 32 (558) 51 (549) 4 (512) 35 27 57 67 9 42 26 49 63 38 53 22 43 43 51 51 44 42 41 44 33 25 54 31 38 44 44 35 55 50 28 26 28 5 37 5O 42 3 3 52 49 37 25 2 30 45 24 14 3 24 47 6O 23 39 52 38 2O - 4 26 5 31 49 19 37 27 27 9 16 36 34 36 (609) 2 (457) 13 (425) 41 (532) 31 (522) Tot. 1623' 1218 1409 1514 1613 P. I. 25.0% 32.7% 6.8% -6.1% . 60 Table 14. Grasselli Spreader-sticker fi?ercentage of emulsifier in nutrient solutifin Control , , . I 0.16g_ 0.082 0.04% 0.024 fi__ 28 32 28 29 36 47 25 42 32 49 47 31 53 33 29 28 6 57 46 39 29 22 45 19 37 31 28 34 30 23 30 36 51 31 6O 47 43 48 33 34 26 33 40 55 37 53 32 46 18 35 17 25 39 42 21 31 26 47 30 23 26. 34 36 30 40 23 33 28 41 37 14 (477) 29 (435) 26 (620) 23 (492) 33 (533) 38 11 12 44 32 29 41 53 55 41 44 36 29 22 15 26 47 43 20 48 51 30 52 32 42 38 20 36 22 57 36 36 32 39 26 43 26 62 33 42 38 23 32 25 44 31 27 22 37 38 47 13 30 44 3 33 32 21 30 40 12 17 24 56 25 31 8 40 33 :5— 36 (533) 9 (376) 28 (516) 33 (525) 26 (539) 26 34 41 37 33 49 38 32 29 45 46 30 34 36 6O 31 41 38 38 28 27 37 51 38 41 31 24 29 40 51 42 35 67 31 34 12 22 33 48 44 35 w 28 44 31 30 31 30 31 43 45 24 38 59 40 40 22 44 35 29 42 28 25 42 60 33 29 30 35 16 30 4« (443) 34 (490) 25 (596) 40 (556) 38 (594) Tot. *1453 1300 1732 1573 1661 P. 1. 10.5% -19.2% -8.3% -14zgfi (I! )(II‘ 61 Table 15. ‘ Triton X-100 Percentage of emulsifier in nutrient solution Control 4 , . 0.163 01084 0.045 0.023 46 16 19 46 37 34 - 27 15 I 38 41 5O 28 . 23 35 36 38 24 36 23 27 36 25 31 38 31 65 42 13 29 33 56 24 16 4O 26 37 21 38 3O 37 56 29 27 29 15 48 13 12 4O 28 38 18 27 39 27 44 5 38 22 29 28 17 32 5 3O 39 6 31 26 33 29 (644) 8 (303) 10 (368) 41 (481) 23 (453) 34 22 23 55 32 35 3O 27 45 38 47 26 27 16 23 45 28 32 43 43 31 32 27 31 17 49 9 18 37 29 26 31 27 25 43 32 14 19 43 45 36 11 11 44 32 51 26 22 4O 21 4O 25 14 9 34 14 2O 7 21 44 33 16 15 3O 24 21 2 22 18 19 28 (522) 10‘ (302) ‘ 21 (312) 3 (460) 2 (446) 37 3O 27 41 3O 37 31 2O 35 29 38 32 >33 29 20 4O 23 20 38 31 39 28 34 35 35 46 27 33 - 35 ' 26 37 35 14 33 42 42 20 22 4O 35 51 24 .28 33 25 28 24 23 25 31 45 20 28 35 28 45 11 3O 11 29 11 31 3O 36 41 3 22 13 13 36 16 (515) 23 (381) 29 (384) 15 (454) 36 (474) Tot. 1681 966. 1064 1395 1373 P. I. 41.4% 36.7% N 17.0; 18.34_ 62 Table 16. Triton X-l50 Percentage 02 emulsifier in nutrient soiutiEZ Control . . , 0-162 0.082 0.042) _ 35 19 20 42 33 19 3O 39 33 26 3O 26 31 15 3O 11 41 3o _ 28 27 37 17 9 34 35 3O 36 24 35 9 39 ' 22 36 29 13 26 34 25 25 3Q 29 26 14 32 12 3 15 28 35 13 28 26 ' 29 12 28 11 33 (458) 10 (283) 5 (350) 15 (393) 31 22 31 35 36 18 32 34 31 24 21 27 31 31 26 23 27 23 . 18 23 32 38 27 29 35 23 28 37 27 26 23 37 3O 19 5 20 3O 7 21 22 33 13 33 31 37 4 15 3O 36 20 23 32 32 21 23 15 16 (464) 21 (303) 30 (353) 19 (413) 30 29 29 4O 29 14 37 28 3O 4 22 18 33 18 14 17 37 18 17 24 36 27 28 24 38 26 17 4 17 33 20 19 24 4O 33 23 23 36 16 13 32 23 11 25 26 36 5 23 9 34 . 27 3 11 28 23 4 15 33 (495) #45 (275) 10 (284) 23 (330) TOE} 1417 " 858 987 1136 6—— P. 1. 39.5% 30.3% 19452 (.1. :11... 1.1 |. ill: e .|....I\n.l‘ 65 Table 17. Triton X-155 Percentage of emulsifier in nutrient solution Control 0.15% 0.08% 0.042 0.02% 45 24 44 45 52 34 37 5o 58 47 50 30 52 42 51 38 43 20 43 7 35 38 19 44 54 55 4o 48 55 38 55 50 31 38 44 37 37 45 4o 35 55 34 47 39 23 48 42 45 4o 40 38 11 - 31 50 52 44 38 47 45 28 28 28 12 19 44 39 28 2 43 12 29 (544) 22 (512) 37 (553) 39 (518) 29 (555) 34 7 58 48 5o 35 49 43 48 45 47 33 43 4o 45 45 22 44 42 2 31 25 ‘ .50 20 23 49 37 13 43 47 25 43 39 47 43 32 50 43 44 3 35 27 . 47 7 42 51 34 45 45 47 4o 58 47 52 33 14 37 55 51 35 3 42 29 45 48 21 34 34 33 47 28 (522) 33 (541) 47 (537) 29 (505) 40 (551) 37 37 23 50 30 37 35 39 33 45 38 54 40 39 40 40 38 49 25 35 39 14 35 31 39 45 15 38 28 7 37 38 40 30 28 42 40 42 45 4o 51 37 24 28 35 28 47 25 43 44 45 43 33 35 19 45 45 28 32 21 11 35 45 19 5 3 40 5o 8 5 15 (515) 9 (528) 13 (525) 45 (494) 7 (402) Tet: 1581 1581 1715 1718 1519 P. I‘ 5'91]; -2003247 -2529; 9.6% 64 Table 18. Triton X-160 Percentage of emulsirier in nutrient solutiUE Control ‘ ' 0.153 0.38p 0.84} 35 33 45 31 33 28 3O 4O 33 3O 28 28 31 25 35 25 41 26 27 33 37 15 18 24 35 8 3O 11 35 24 2O 13 35 5 33 35 3' 4O 5 28 29 22 36 42 12 5 28 19 35 3 3O 25 29 26 10 39 33 (458) 10 (311) 35 (412) 3 (395) 31 32 33 39 3 11 35 32 31 21 38 15 3 26 31 18 27 l4 13 32 32 35 31 41 35 24 37' 33 27 12 33 28 3O 22 25 28 3O 3O 24 6 3 25 39 3O 37 25 44 13 35 17 42 31 32 8 45 24 ‘ 16 (464) 5 (309) 27 (499) 5 (373) 30 28 49 18 29 27 29 45 3 34 28 39 33 35 35 43 37 '3 29 35 35 24 33 19 38 28 9 34 33 25 23 25 4O 19 32 34 35 25 15 23 22 28 26 38 3‘ 11 31 33 34 29 41 27 28 24 31 5 33 (495) 42 (412) 33 (446) 35 (455) Tdt; 14177 1532 1357 1224 g. I. 27.2% 4.25 13-85 55 Table 19. Triton X-l77 Percentage of emulsifier in nutrient solution Control , 4 0.15% 0.08% 0.04% 0.024 33 35 46 38 28 25 35 25 38 38 38 31 36 27 37 29 32 39 44 3O 25 27 41 3O 14 3O 41 36 13 28 36 4O 4O 45 4O 12 16 37 33 32 34 29 3O 33 33 12 27‘ .27 33 32 25 28 49 31 34 28 39 25 4O 23 22 26 32 30 ll 22 33 25 28 3O 43 (415) 29 (459) 19 (510) 22 (459) 30 (440) 38 23 36 12 22 31 42 37 28 23 41 29 45 31 26 4O 23 15 34 35 32 37 35 35 _ 35 27 9 42 47 33 43 29 39 30 27 28 23 29 25 28 27 38 41 26 29 17 l4 13 44 14 38 28 27 3O 19 11 27 17 34 29 37 7 26 43 26 34 42 22 28 29 33 (477) 29 (400) 13 (437) 44 (490) 29 (405) 36 4O 31 39 42 38 4O 42 43 36 3O 35 43 25 14 42 34 34 40 34 31 28 35 3O 35 27 14 38 39 43 25 30 38 37 15 49 2O 33 32 3O 30 34 37 38 9 42 29 28 31 29 45 . 29 23 39 30 33 25 21 26 23 41 34 43 24 38 ll 38 4 37 29 33 (515) 18 (448) 12 (462) 7 (487) 41 (448) ‘Tot. 1407 91317 1409 1472 1293 P. I; 644% -O.;% ' ..4.8% 8.1: ‘56 Table 20. Triton X-188 Percentage of emulsifier in nutrient solution Control _ , , 3 0.15% 0.08% 0.044 0.024 33 30 28 35 38 25 30 19 35 38 38 ' 28 39 29 29 29 18 33 30 38 25 25 9 37 31 30 10 31 29 30 35 29 17 35 15 12 20 15 12 27 34 25 30 9 25 12 29 32 23 17 25 20 28 22 30 28 28 33 15 38 22 25 33 19 4 22 23 33 13 30 43 (415) 3 (344) 11 (392) 11 (359) 37 (429) 38 5 . 28 29 37 31 3 22 37 13 41 29 24 17 13 40 27 23 15 32 32 25 27 27 15 27 28' 27 23 18 43 21 27 24 40 28 25 33 25 31 27 38 33 33 28 17 27 33 31 22 38 28 31 38 25 11 23 20 21 18 37 35 30 17 12 34 13 20 25 27 33 (477) 12 (341) 8 (385) 13 (375) 18 (351) 35 21 29 24 24 38 12 24 21 42 30 32 20 25 25 42 14 31 25 21 31 30 29 28 25 27 28 29 32 20 25 15 30 33 29 49 15 25 28 34 30 4 11 27 27 42 20 32 28 41 45 31 15 35 28 33 25 25 30 33 41 25 27 39 25 11 21 23 5 25 33 (515) 11 (307) 9 (352) 23 (404) 33 (434) Tot. 1407 992 1140 1139 1214 P. I. _ 29.5% 19.0% 19.0% 13.7% 67 Table 21. Triton B-1956 Percentage of emulsifier in nutrient solution Control 4 , 0.15;“. 0.087”: 0.0475 0.02); J 35 12 42 37 21 28 43 24 38 ll 23 35 46 36 35 25 45 27 38 25 31 25 48 29 24 26 42 3O 33 36 16 16 35 37 16 24 21 45 41 39 39 28 10 27 26 27 25 . 39 19 10 36 24 33 25 19 33 33 34 14 4O 28 29 42 8 5 24 33 46 13 2 - 8 (403) 32 (443) 11 (512) 3 (398) 38 (347) 30 35 34 36 13 44 39 37 27 31 39 38 45 36 37 32 29 25 4O 27 31 27 6O 38 36 29 28 46 47 35 39 18 4 41 23 19 32 21 42 36 26 45 24 36 41 18 44 35 38 14 30 20 10 44 35 24 36 11 49 46 29 29 3O 35 26 14 34 49 23 36 13 (417) 45 (499) 58 (528) 31 (553) 25 (451) 41 36 48 33 43 3O 41 31 18 28 35 49 34 28 37 24 28 ' 23 15 24 31 33 42 23 47 21 31 28 46 47 3O 37 19 24 23 20 36 39 27 36 27 36 37 27 32 28 39 37 35 26 28 , 22 38 22 22 45 21 ’ 39 24 9 34 4 24 24 3O 2O 3 31 22 4 3 (417) 3 (419) 10 (480) 15 (383) 21 (429) T0 . 1237 1361 1523 1344 41237 P. I. -1000 -2209% ' .8.%: 0.0 68 Table 22. Emool H-77 Percentage of emulsifier in nutrient solution Control 4 , , , 0.16jo 0.08%: 0.0470 0.02% 59 54 42 51 52 55 48 66 51 78 44 33 35 35 44 47 65 47 29 61 34 45 50 45 12 53 53 33 51 78 35 53 77 36 4 60 62 50 52 5 48 51 35 41 35 47 61 58 28 46 21 63 56 40 43 45 63 27 58 23 52 68 12 36 27 20 73 23 34 52 25 (545) 25 (807) 21 (532) 12 (599) 27 (587) 33 29 43 43 37 33 27 21 51 35 36 42 3O 51 33 30 32 44 46 63 53 20 24 35 18 34 64 5 53 81 56 5 25 47 45 64 33 51 33 46 41 17 51 54 24 36 51 35 39 42 39 6 33 26 53 33 41 45 22 28 28 7 ' 56 21 21 22 35 8 31 17 79 (617) 64 (473) 65 (588) 48 (600) 46 (589) 33 29 53 31 15 3 56 59 48 52 58 16 38 61 31 38 34 64 29 56 47 50 4O 5O 36 32 49 56 23 36 27 45 27 40 56 61 55 59 39 53 44 49 48 45 56 41 38 31 61 67 38 44 40 41 30 4O 46 47 42 10 23 42 3 8 57 33 43 ‘ 5 30 3O 15 (552) 44 (540) 59 (539) 35 (583) 40 (525) Tot. 1824 1920 1885 . 1782 1801 P. I. -5.3% ' -3.3% 2.3% 1._g - 59 Table 23. DDT 25$, Xylene 715, anu AreSAap 5O 4p Percentage of concentrate in nutrient solution Control . 0.93 0,454 0-22% nl1131 52 57 44 47 51 47 20 37 53 55 38 53 43 30 23 44 38 10 43 48 53 57 51 50 55 68 70 48 48 50 45 39 52 30 51 55 37 40 55 55 58 12 35 34 55 48 75 57 40 39 57 31 45 45 59 47 34 57 55 54 43 51 51 13 49 45 41 53 54 41 54 (755) 43 (558) 32 (575) 58 (707) 25 (733) 50 50 51 38 55 50 44 58 74 28 48 35 70 31 34 52 47 35 51 45 40 45 51 55 58 78 17 43 30 54 71 31 70 50 25 55 52 40 75 51 21 54 33 57 35 30 35 51 27 42 49 48 47 59 55 71 35 57 32 35 57 55 45 58 29 39 54 5 54 49 58 (829) 54 (571) 29 (725) 35 (737) 53 (558) 17 79 51 55 52 50 18 25 59 58 57 53 37 55 50 50 18 57 50 31 59 42 38 49 48 58 43 31 48 33 54 58 35 57 39 58 45 49 55 50 58 54 52 53 48 53 44 49 23 33 58 24 71 43 39 51 50 40 25 50 35 45 43 51 48 10 19 . 45 48 52 20 (739) 44 (545) 50 (595) 24 (708) 58 (599) Tot. 2334 1975 2095 2152 2100 P. I. 15.45 10.2% 2.8% 10.05_ Table 24. DDT 25%, Xylene 712 and 70 Polyethylene Glycol 400 (Mono) Laurate Percentage of concentrate‘in nutrient solution. Control 0.9; 0.452;, 0.222 0,112) 55 56 5O 28 17 45 21 27 22 37 43 27 26 27 25 5O 59 22 25 25 54 25 25 5 55 39 57 24 22 25 58 52 10 27 45 59 29 28 25 25 32 13 4 31 35 51 4O 55 5 51 50 26 50 10 54 5O 18 21 5O 28 21 10 28 28 25 17 2O 26 2O 51 45 (506) 26 (417) '54 568) 51 (552) 2 (417) 29 54 _ 26 11 55 29 58 19 21 44 28 25 25 29 15 49 5 54 12 59 55 5O 55 28 29 52 5O 5O 25 45 55 4O 22 25 51 18 24 16 25 26 55 27 26 25 5O 27 39 47 25 -35 25 52 47 51 25 12 16 21 4 27 55 52 26 4 ‘ 29 27 2 28 21 28 27 (461) 25 (599) 25 (425) 25 (510) 51 (467) 42 21 54 16 48 45 24 29 5O 7 43 ‘ 31 25 32 29 44 55 59 16 27 18 29 25 29 24 45 28 22 2 5O 41 28 25 26 59 22 4 25 29 24 52 59 55 41 19 11 25 24 4O 25 25 4O 55 29 29 12 51 54 17 5O 15 24 4O 28 2 5 29 ' 29 30 27 fl 5 (401) 10 L395) 31 (444) 25 (39c) 35 (414) Tot. 1568 '1212 1255 1052 1298 P. I. 11.4% 9.T@_ 24.6% _5-1% 71 Table 25. DDT 25%, Xylene 71% and Triton X-100 4% Percentage of concentrate in nutrient solution Control 0 . 9:15 c 14554; J . 223,0 0 . 115); 54 19 _ 38 47 34 59 17 25 34 32 59 22 32 35 23 45 15 33 34 35 47 25 39 31 35 33 24 23 3o 30 3o 15 32 25 39 42 38 20 31 37 38 27 3o 17 28 55 22 33 29 33 29 27 22 42 27 35 30 37 33 41 34 29 21 27 25 34 32 25 _24 31 37 (531) 25 (358) 33 (444) 25 (455) 24 (475) 42 31 3o 35 25 39 3o 2 21 33 35 24 3 34 32 29 29 35 4o 35 4o 25 32 48 32 37 38 34 23 29 3o 32 34 41 33 31 29 31 35 32 33 3o 33 33 32 39 20 45 25 28 35 13 31 32 25 37 23 35 43 39 22 17 33 31 33 30 - 20 32 35 35 25 (505) 22 (384) 27 (437) 29 (509) 21 (455) 31 15 27 41 38 52 22 27 12 39 38 27 31 32 39 35 38 29 35 35 32 28 33 29 24 23 24 23 49 4o 55 59 15 28 5O 28 43 7 33 45 28 34 39 39 34 32 25 35 3o 39 30 34 35 33 29 35 25 38 32 18 35 23 35 25 18 28 24 22 28 39 3 (507) 23 (425) 38 (433) 2 (450) 40 (507) 'bef. 1544 1178 1314 1424 1449 P. 1.- . 28.35 '20115 13.42 11.9412 72 Table 25. DDT 25%. Xylene 71p and Tirton 2-155 4% Percentage of concentrate in nutrient solution Control _. 0.95 0.45% 0.22% 0.11% 33 25 29 29 30 45 3 48 28 35 43 29 29 43 20 30 23 32 20 30 34 29 29 31 31 39 23 34 49 29 38 17 38 25 35 39 15 25 28 11 32 25 35 2 43 31 38 28 27 28 30 25 43 25 23 30 18 25 24 31 21 24 f 3 27 39 17 7 , 25 29 22 43 (505) 25 (329) 17 (441) 38 (427) 25 (433) 29 25 28 57 27 29 29 22 . 33 37 28 25 39 25 35 49 28 24 35 57 35 5 37 30 42 32 28 24 35 34 33 31 - 43 48 .24 18 38 30 40 24 55 45 29 28 25 27 35 42 24 40 25 45 29 . 49‘ 4 12 43 27 27 3 35 43 44 30 2 27 22 25 20 37 27 (451) 29 (473) 10 (453) 34 (515). 27 (419) 42 4 . 45 5 45 45 25 48 52 30 43 3 32 48 25 44 14 35 37 45 18 28 24 8 30 43 28 31 3 25 41 ' 40 20 39 41 22 44 29 29 55 32 10 37 30 34 11 31 19 30 28 25 20 12 29 45 12 30 27 25 45 13 28 29 25 40 5 32 30 29 37 5 (401) 20 (357) A13 (432) 27 (417) 15 (544) ‘T51. 1358 1159 1325 1359 1395 P. I. 15.3% 3.1% 0.7% -2.rfi Table 27. DDT 25%, Xylene 72% and 35551 H-77 3% Percentage of concentrate in nutrient solutIOn Control , , . 38 29 35 31 45 25 32 12 42 25 49 29 30 30 41 55 30 30 48 28 37 35 34 5 23 41 47 34 42 39 34 33 43 57 47 14 39 24 30 35 12 42 38 43 33 43 30 38 37 22 33 40 40 39 35 22 40 14 38 34 49 35 34 39 33 30 31 40 34 33 48 (530) 15 (508) 43 (490) 33 (548) 21 (494) 37 25 47 45 45 51 33 23 55 52 51 29 43 24 45 43 24 30 45 43 50 32 51 42 44 ~50 45 44 59 47 37 37 48 39 44 40 33 4o 35 38 35 30 42 49 43 52 34 32 54 41 49 32 33 35 40 55 30 39 . 45 45 38 39 39 55 43 48 11 10 42 40 58 (724) 31 (455) 27 (558) 7 (534) 42 (558) 39 39 42 30 32 51 38 35 35 39 28 30 9 27 43 37 30 34 37 11 29 45 31 35 39 42 32 29 31 32 50 40 45 15 35 49 25 32 29 35 54 25 35 33 47 35 38 29 29 34 39 35 30 37 44 39 45 28 40 33 30 4 35 43 29 40 (511) 20 (484) 44 (504) 35 (501) 35 (515) “255. 1853 1458 1552 1583 1557 P. I. ' 21.4% 15.75 9.72 10.5% Triton 1-155 25 74 Table 28. DDT 254, Xylene 705 and Triton B-l956 35 Percentage of concentrate in nutrient solutfbn Control . , , 0.95 0.454 0.225 0.112% 38 40 37 .34 30 25 53 49 51 15 49 50 30 31 5 55 35 37 43 31 37 50' 45 41 47 41 37 43 45 50 34 50 43 44 41 14 48 37 34 44 12 31 25 34 34 43 45 47 55 40 33 19 42 35 30 22 39 34 41 45 49 47 40 38 31 30 48 35 35 28 48 (530) 51 (543) 42 (589) 25 (585) 30 (501) 37 27 31 45 49 51 44 48 54 50 51 49 44 50 48 3 38 48 45 40 50 39 37 45 49 50 42 28 41 49 37 45 43 51 44 40 50 35 38 52 35 35 33 25 45 52 47 32 42 55 49 35 41 34 45 55 58 39 39 57 38 39 42 43 '39 48 34 15 35 50 58 (724) 49 (533) 25 (542) 42 (531) 59 (743) 39 42 45 35 30 51 47 45 45 35 28 40 28 39 11 37 43 21 45 40 29 40 45 39 42 42 40 43 43 41 50 37 50 38 50 49 43 25 30 45 54 22 32 48 58 35 33 35 49 32 39 44 38 43 47 39 34 49 40 45 39 37 42 45 44 30 -47 33 29 33 40 (511) 3 (552) 25 (558) 15 (584) 25 (579) Tot. 1865 1828 *1589 1801 1823 r..1. ' 1.9% 9.3% 3.3% 2.1% Triton x-150 2% 75 Table 29. DDT 25%, Xylene 72% and Triton x-150 15 Percentage of concentrate in nutrient solution Control , 4 0.9% 0.45% 0.22% 0.115 54 43 33 38 38 59 32 49 45 41 59 35 52 39 43 45 51 23 32 55 47 28 35 55 55 33 37 31 44 48 30 23 3o 35 41 42 2 43 33 28 38 39 39 22 35 55 40 35 32 22 29 38. 27 a. 32 18 35 27 35 30 43 34 37 37 25 33 34 39 45 35 13 37 (531) 38 (534) 38 (554) 35 (534) 2 (517) 42 30 28 34 48 39 42 41 49 51 35 28 45 48 45 29 34 34 40 29 40 40 23 25 22 37 30 29 33 33 30 3o 55 55 33 31 32 35 35 23 33 35 29 39 30 39 41 38 49 33 35 57 51 34 27 37 31 33 35 35 22 35 51 35 35 3o 32 40 ,37 31 25 (505) 13 (511) 29 (573) 37 (599) 49 (523) 31 30 29 31 53 32 35. 29 24 44 52 42 39 35 48 38 25 45 30 35 35 32 35 24 44 23 54 33 35 49 33 25 28 43 45 28 34 28 45 25 28 17 27 41 35 32 45 24 35 25 30 47 32 33 42 35 23 15 30 30 35 33 30 23 20 28 5 55 30 34 __fi37 (507) 5 (454) 33 (483) 21 (483) 20 (550) Tot. 1544 1499 1510’ 1515 1590 P. I. 8.8% 2.1% 1.35 3.3% 75 Table 30. DDT 25%, Xylene 72% and Aerosol 0T 35 Percentage of_concentrate in nutrient solutiofi_ Control , . 0.9; 0.451 0.225 0.115 52 3 27 37 55 71 3 32 33 73 32 4 15 35 42 40 2 9 43 48 37 3 29 29 42 35 5 42 40 17 30 4 10 41 34 37 5 37 45 31 55 3 30 40 31 58 3 23 28 44 43 5 23 25 3c 35 4 19 38 49 50 5 38 21 45 44 5 5 29 38 38 (559) 5 ( 60) 22 (352) 35 (520) 33 (513) 35 3 13 28 23 34 8 23 29 25 44 8 ‘ 31 35 33 35 8 35 32 51 37 7 35 42 30 35 5 18 47 3- 37 8 9 2c 33 40 7 2o 32 52 45 7 24 34 7 28 8 34 41 5o 29 3 31 35 32 38 5 22 15 38 29 3 12 35 31 30 5 25 35 25 29 (529) 3 ( 91) 25 (359) 7 (459) ‘9 (493) 50 4 29 33 51 35 7 17 44 52 44 5 19 48 41 45 8 24 40 55 52 8 31 39 33 38 10 15 53 29 47 8 25 4c 28 38 11' 25. 41 25 34 7 25 25 43 31 7 13 54 3 28 8 21 35 44 47 2 12 49 44 4o 8 24 39 37 35 7 7 4 35 30 (595) 8 _(109) 20 (310) 44 (590) 25 (510) Tot. 1525:: 250 ‘1031? ”"‘1579 1715 P. I. 85a8% 43155 13.44 5145 77 Table 31. DDT 25%, Xylene 71% and Toximul 500 4% Percentage of concentrate in nutrient solutTOn Control , 1 , ' 9:9; 0.45270 4352:3210 0.1120 56 34 68 63 71 45 19 57 44 68 79 43 66 7O 42 35 17 58 4O 58 48 42 50 43 51 33 4O 42 65 69 62 50 44 6O 46 34 38 26 47 52 66 28 23 39 66 58 36 48 52 53 56 26 46 3O 49 23 20 41 6 26 33 17 65 7 6 47 2O 6O 6 6 30 (734) 25 (427) 9 (713) 11 (553) 23 (682) 60 36 63 51 68 56 28 51 47 58 62 36 48 68 72 44 26 35 59 67 52 3O 35 65 43 45 46 51 55 71 51 44 51 3’ 50 39 46 64 33 63 76 32 47 36 66 52 9 47 55 64 59 35 14 42 28 39 47 44 29 3O 31 20 29 37 46 51 4 3 29 26 42 (759) 6 (445) 3 (555) 11 (555) 35 (777) 53 4O 12 44 4O 45 53 26 44 59 43 34 23 51 36 48 3O 44 57 28 56 35 44 47 67 51 41 12 62 37 73 37 37 56 46 39 69 55 45 52 20 3O 65 58 24 57 32 ' 26 4O 68 45 25 24 44 88 33 62 49 36 45 25 17 51 39 41 14 31 41 17 ll __ 18 (620) 37 (553) 39 (548) 24 (633) 6 (618) Tot. 2093’ 2'1428; 1845 ‘1901’ *—2077 P. I. 31.9% 11.8% 9.2% .85 78 Table 32. DDT 25%, Xylene 595 and Toximul 400 6% Percentage of concentr1te in nutrient solution Control _ , 0.92 0.45% 0.22% 0.11% 49 39 27 39 37 49 41 54 34 39 63 32 22 22 35 53 38 45 41 46 6O 54 35 56 18 57 39 4O 44 3O 53 _ 33 31 53 33 64 38 45 64 35 54 17 29 36 3O 28 11 38 58 37 49 19 39 39 45 57 35 35 28 3O 42 26 19 36 3O 53 45 2O 33 25 62 (793) 56 (523) 37 (516) 36 (619) 16 (486) 28 34 41 43 3O 6O 45 37 37 57 56 39 7 36 39 28 37 4O 46 57 6O 26 67 36 38 5O 33 28 32 36 44 26 45 29 51 64 5O 52 42 58 33 9 39 28 54 4O 32 45 38 38 12 47 4O 32 4O 19 45 43 21 62 51 10 53 41 56 56 29 22 15 42 61 (662) 43 (505) 4 (563) 3 (510) 26 (684) 55 33 5O 46 64 77 41 52 27 43 59 46 33 39 6 48 47 14 3 5O 27 26 37 7 37 58 43 6O 34 5O 54 11 51 45 60 58 8 45 31 54 32 49 42 55 46 69 51 48 . 22 59 58 4O 43 49 19 45 26 17 3O 26 53 . 17 45 21 32 33 56 35 21 29 30 (756) 19 (513) 24 (596) 42 (500) 39 (612) Tot. 2211 1541 1675 1629 1782 P. I. 30.3% 24.2; 21.8; 19.4% 79 Table 33. DDT 25“, Xylene 73% and Santomerse D 2% Percentage oficoncentrate in nutrient solution Control 0.9% 0.45% 0.22% 0.11%_ 52 27 43 48 51 71 35 22 33 32 32 3o 45 53 57 4o 31 4o 29 54 37 42 37 29 34 35 45 52 33 34 3o 35 28 ' 3o 45 37 57 38 5o 21 55 35 4o 47 37 68 41 37 35 45 43 44 38 57 43 35 28 27 24 31 5o 44 28 43 32 44 33 31 38 32 38 (559) 39 (558) 11 (517) 37 597) 35 (594) 35 29 35 43 21- 34 35 58 25 41 44 38 59 38 47 35 37 45 43 35 37 33 32 43 45 35 28 52 58 48 37 3o 55 29 32 4o 24 34 34 38 45 3 42 32 38 28 27 43 51 48 29 28 - 51 32 55 38 28 11 25 41 29 34 19 , 34 42 3o 3 44 35 51 29 (529) 25 (453) 23 (514) 28 (550) 39 (523) 50 35 53 38 54 35 32 38 34 5o 44 33 49 43 , 68 45 31 4o 45 35 52 38 33 25 4o 38 35 53 25 71 47 43 33 , 23 47 38 3o 22 25 25 34 32 35 34 37 31 45 35 35 39 28 35 15 33 59 47 47 35 38 39 4o 3- 49 31 31 35 59 31 28 4o 30 (595) 45 (573) 35 (579) 29 (489) 45 (696) Tot. I793 1604 . 1710 1636 1913 P. I. 10.5% ___ 4.5% 8.8% -5.7% PEYTOTGXIC INDEX AND WEIGHTS IN 3RAHS OE CUCUHBER PLANTS 80 DDT Formulation* Percentage of concentrate in nutrient solution *Only the emulsifier used is given for each formuiation, \. A fiv— Each figure represents the total for forty 11v? plants. h,— Control 0.9% 0.45% 0.822 0.113.... Aerosol QT 1.721 .585 1.220 1.455 1.595 g, Toximul 300 2.321 2.000 2.050 2.146 24452 1 13.8% 11.7% 7.5% -5.7% Toximul 400 2.440 1.795 1.890 1.925 2.050 Santomerse D 1.721 1.665 1.828 1.741 1.951 3020/0 -602% -10270 “130470 Areskap 50 2.605 2.375 2.520 2.565 2.488 808% 503% 105j0 405770 Polyethylene 1.610 1.520 1.490 1.335 1.585 Glyco 400 5.6% 7.5% 17.1% 1.6% Triton X-100 1.990 1.615 1.703 1.930 1.811 1808/0 1404/0 300;} 106,12 Tritons x-150 1.990 1.995 1.790 1.920 2.140 & X-léo ~O‘3‘k 10.576 3.570 -705i0 Triton X-155 1.610 1.645 1.665 1.834 1.725 . “2027-0 -304‘20 -lsogio '70170 Tritons X-155 2.197 2.860 2.460 2.540 2.510 85 B-l‘JSO -30.2‘;0 -1200?) -1506?!) -1402?) Emcol H-77 2.197 2.045 2.194 1.970 2.125 5.9% -0.1% 10.3% 3.3% ‘ x HICHIGQN STRTE UNIV. LIBRRRIES 1111 57 82 III) III) 1 (H11) 9 1 1 312 3003