STUDIES ON THE NUTRITION AND PHYSIOLOGY OF PICKLING CUCUMBERS By CONRAD HENRY MILLER AN ABSTRACT Submitted to the School for Advanced Graduate Studies of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Horticulture 1957 Approved ProQuest Number: 10008388 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest, ProQuest 10008388 Published by ProQuest LLC (2016). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 4 8 1 0 6 - 1346 ABSTRACT CONRAD HENRY MILLER The effects of night temperature, daylength and nitrogen level on two varieties of pickling cucumbers were studied under greenhouse conditions# Low night temperature (60°F#) increased the length to diameter fruit ratio by six percent and the production of pistillate flowers by 60 percent when compared to the high night temperature (70°F#)• Soil culture grown plants receiving weekly applications of one gram of ammonium nitrate for seven weeks produced three times as many fruit as the plants which received no additional nitrogen* High nitrogen also resulted in an increase in the length to diameter ratio of fruit* Plants grown at 70°F. night temperature produced more fruit at the 11 hour daylength than at the 15 hour daylength, while at 60°F. night temperature, plants produced more fruit under long day conditions* In field studies, fertilizer at the high rate (400 pounds per acre of 5-20-20), when placed two inches below the seed resulted in decreased stands and the poorest yields of two varieties of pickling cucumbers. Highest yields of both varieties were produced on plots receiving 100 pounds per acre of 5-20-20 in a side-placed application. The variety Wisconsin SMR-12 produced markedly higher yields with the low broadcast fertilizer application and with the high under the row application than Wisconsin 70, indicating that Wisconsin SMR-12 probably was less sensitive to fertilizer injury and had better foraging ability than Wisconsin 70* In another field experiment, plots receiving a side-placed application of 50 pounds per acre of potash from KC1 produced higher yields of ABSTRACT CONRAD HENRY MILLER pickling cucumbers than plots receiving 100 pounds per acre of the same material. Nine treatment combinations of rate and time of nitrogen application varying from none to a total of 90 pounds per acre interacted with the two potash levels had no consistent effects on yield or length to diameter ratio of the fruits. A survey of 19 pickling cucumber fields in Michigan indicated much variability in fertilizer practices, but that a rye cover crop proceeding the cucumbers was associated with highest yields. Analysis of petiole samples taken at vining, mid-season, and at the last harvest indicated inverse relationships between soluble nitrogen and phosphorus and between potassium and calcium; and a marked increase in soluble magnesium during the season was noted. Comparison of petiole analysis data with yields showed nitrogen to be the most limiting nutrient and phosphorus the second, with no apparent limitations due to potassium, calcium or magnesium. Values for soil potassium and phosphorus as shown by the Spurway active tests suggested very little relationship with yields. From this investigation it was concluded that the pickling cucumber is quite responsive to fertilizer but is easily injured by it. This would suggest that growing the crop on soils well supplied with organic matter and the use of irrigation and frequent applications of soluble fertilizers would be conducive to high yields* STUDIES ON THE NUTRITION AND PHYSIOLOGY OF PICKLING CUCUMBERS By CONRAD HENRY MILLER A THESIS Submitted to the School for Advanced Graduate Studies of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Horticulture 1957 ACKNOWLEDGEMENTS The author wishes to express his sincere appreciation to Dr* R* L. Carolus for his guidance and assistance throughout the course of the investigation, and to Dr. S. K. Hies whose assistance and constructive criticisms have been most helpful. Thanks are also due Drs. G. P. Steinbaur and K. Lawton, members of the author’s Guidance Committee. The assistance of Dr. W. W. McCall with the 1955 field studies is also acknowledged. The author is deeply indebted to his wife without whose encouragement and understanding this manuscript would have never been written. The financial assistance from the National Pickle Packers Association is also gratefully acknowledged. TABLE OF CONTENTS Page INTRODUCTION............................................... 1 REVIEW OF LITERATURE............................ . ......... 3 Field Fertilizer Studies . 3 Vegetative Growth, Flowering and F r u i t i n g ............. . . 8 Chemical Composition of Plants and F r u i t s ................... 12 EXPERIMENTAL OBJECTIVES.............................. 15 EFFECTS OF NIGHT TEMPERATURE, DAYLENGTH, ANDNITROGENLEVEL . . Materials and Methods...................................... Results and Discussion........... . , . . . 16 16 17 Y i e l d.................................................... 17 Length to diameter r a t i o .................. * .......... 19 Flower sex rat i o ............. 22 INFLUENCE OF FERTILIZER TREATMENTS CM YIELD AND QUALITY . . . . 25 Materials and Methods 25 ... ...... 26 Fertilizer rate and placement................. Rate of potash, and time and rate of nitrogen ........... Results and Discussion............... 26 27 Fertilizer rate and placement............ 27 Rate of potash and time and rate of nitrogen............... 34 SURVEY OF THE NUTRITIONAL STATUS OF PICKLING CUCUMBERS . . . . . 38 Materials and Methods 38 ......... Results................ Association of cultural practices with yield ............... 39 39 Page Fresh tissue analysis.................................... 39 Soil analysis • 48 Total analysis of cucumber vines and f r u i t ............... 52 Discussion............................................... 55 GENERAL DISCUSSION ....................................... 58 SUMMARY ................................................... 62 LITERATURE C I T E D ................................... 64 INTRODUCTION Michigan is the leading state in the production of cucumbers for pickles, producing 25 to 35 percent of the nation* s total. The cucumber is the most important processing vegetable grown in Michigan representing 60 percent of the acerage and 50 percent of the value of processing vegetable crops. Because of the large amount of hand labor required, pickling cucumbers were formerly grown on small plots and harvested by family labor. Therefore, there was little organized interest in the crop. However, disease resistant varieties and the use of migrant labor in harvesting have made it possible for fewer growers to plant larger acerages, resulting in an increase in the importance of the industry to these growers, and a greater demand for research. Although numerous studies have been conducted on the effects of temperature, light and pollination on vegetative growth, flowering and fruiting, and considerable improvement in varieties has been accomplished, nutritional research has not kept pace with the growth of the industry. A grower of pickling cucumbers receives only one half of the gross value of the crop; the other half goes to the pickers. Therefore, high yields are doubly important, both to the grower and to the pickers. Even if mechanical harvesters are perfected, the cost of harvesting will remain high because the cucumbers must be harvested ten to 15 times during the season. Not only are total yields important but concentrated early yields are also important because processors want cucumbers early in the season and because most disease and insect problems develop during the latter portion of the season. In addition to higher yields, such quality factors as shape, length to diameter ratio, color, firmness and texture of the fruit must be considered, because processors desire a high quality product. REVIEW OF LITERATURE Field Fertilizer Studies Mich of the previous work on the nutrition of pickling cucumbers and related crops has been in the form of field trials in which the effects of fertilizers and animal manures, alone or in combination, on the yield or quality of the fruit have been studied. Research by Seaton, et al (1936) indicated that 300 to 500 pounds per acre of 4-16-4* in addition to manure, produced satisfactory yields of pickling cucumbers under Michigan conditions. They also observed beneficial effects during cool wet seasons from 16 to 40 pounds of nitrogen applied as nitrate of soda or ammonium sulfate as a sidedressing. In a more recent study, Wittwer and Tyson (1950) conducted fertilizer trials at three locations in Michigan. Their results show that band applications of up to 500 pounds per acre of 3-12-12 were profitable with pickling cucumbers on fairly productive soils. Side- dressing with 200 pounds per acre of ammonium nitrate was not beneficial except on poorly drained soils of low fertility. A ten year study conducted in Illinois by Lloyd and McCollum (1940) comparing the use of fertilizers plus cover crops with manure in a four year rotation showed that it was possible to produce satisfactory yields of pickling cucumbers without manure. Although an excellent yield was produced on plots treated with 20 tons of manure per acre, the highest yield was observed on the cover crop series which had been treated with 1000 pounds per acre of 6-8-4. Other treatments in the cover crop series included 1000 pounds per acre of 0-8-4* 4-8-4* 4-0—4* 4—12—4* and 4-8-6. Phosphorus caused the greatest increase in early and total yields. Results of a long-time fertility study conducted in southern Ohio and involving a four-year rotation of slicing cucumbers, tomatoes, sweet corn, and cabbage, (Magruder, 1923) indicated that cucumbers were benefited from annual applications of one ton per acre of ground limestone, alone or in combination with manure. Later, Comin and Bushnell (1928) reported that slicing cucumber yields were not increased by liming during the early years of this experiment although the soil had fan initial pH of 5.6 and indicated that applications of 77 pounds of nitrogen supplimented by superphosphate gave marked increases in yield. Even with applications of approximately 160 pounds per acre of nitrogen from manure and nitrate of soda, yields were still increasing and no indication of the upper limit of profitable application was reached. Only small quantities of phosphorus were needed on this soil, and addition of potassium was not profitable. However, two years later according to Bushnell (1930), potassium had become limiting and cucumbers showed the highest response to this element of the four crops tested. Comin (1938), reported that both total and early yields of slicing cucumbers were increased by the use of complete fertilizers. The report of Bushnell (1941) indicated that the use of manures continued to be of great importance, especially during dry seasons. On the basis of recent results in this study, he recommended 1000 pounds of 8-8-8 fertilizer per acre supplemented by one nitrogen side dressing. Work at the Arkansas Fruit and Truck Branch Experiment station by Cooper and Watts (1934) revealed that the omission of phosphorus from the fertilizer caused a heavy reduction in the yields of pickling cucumbers. They indicated that phosphorus was the most limiting element followed by nitrogen and potassium in that order. The source of nitrogen was relatively unimportant but highest yields were secured by the use of sodium or calcium nitrate. In a later publication Cooper and Watts (1940) reported high returns from the use of manure. For pickling cucumbers in Mississippi, Anderson (1939) recommended 800 to 1000 pounds per acre of 4-8-6 or 6-8-6. Later work by Anderson (1941) showed that maximum yields were obtained with the use of 800 pounds per acre of 6-8-12. He recommended 800-1000 pounds per acre of 6-8-8 for new land and the same rate of 6-8-12 for older, heavily cropped land. both cases the use of supplementary nitrogen was suggested. In Another report by Anderson (1943) indicated that the most profitable yields were obtained with 500 or 1000 pounds per acre of 6-8-6 fertilizer with little difference in the net returns between these two rates. Later trials in Mississippi by Phillips (1955) indicated that 16 pounds per acre of nitrogen in combination with 64 pounds per acre each of phosphoric acid and potash were optimum and that 48 and 80 pounds of nitrogen caused appreciable decreases in the yield of cucumbers. In a two-year test in Alabama, Ware, et al (1953) found that the yield and value of pickling cucumbers were benefitted by increasing the rate of application of 8-8-4 from 400 to 800 to 1,200 pounds per acre when used in conjunction with six tons of manure or irrigation or both. In general, irrigation was more profitable than manure and fertilizing at the higher rates under irrigated conditions markedly increased net profits. Work by Barnes (1934) in South Carolina indicated that both basic slag and lime improved color and yield of slicing cucumbers. Omission of potassium from the fertilizer resulted in lowered production. Another report by Barnes (1941) showed no increase in cucumber yields by using 5-10-5 fertilizer in increments of 250 pounds from 500 to 1250 pounds per acre. Split applications or side dressings caused no differential yield responses. He suggested that 1000 pounds per acre of 3-7-5 may be sufficient for this crop. An anonomyous report from North Carolina (1940) indicated that high rates of nitrogen improved the color and decreased the percentage of misshapen fruits. The lowest rate of nitrogen used produced 40 percent misshapen fruits with a tendency to have a pale green or yellow color at the dill size. In Virginia, Carolus and Brown (1935) observed a marked increase in plant growth, early and total yield of better shaped fruit when a soluble form of magnesium was included in the fertilizer. Results of fertilizer experiments conducted by Reynolds (1954) on a sandy loam soil in Maryland showed no differential yield responses of pickling cucumbers to applications of calcium, magnesium, borax, nitrogen, phosphoric acid, and potash on a high producing Held. According to Jacob and White-Stevens (1941)> 60 pounds of magnesium oxide per acre showed a consistent stimulating effect upon flavor, total dispersed solids, and sugar concentration in the fruit of muskmelons. There was a distinct depressing effect on these constituents when magnesium was interacted with boron indicating that each element inhibited the beneficial effects of the other. Potash had a depressing effect on flavor, total dispersed solids and sugar content, when used alone and in combination with the other two elements. Eisenmenger and Jucinski (1939) observed that calcium hastened maturity and increased sugar content in cantaloupes and watermelons, by about two weeks. In general, applied magnesium was more readily absorbed than calcium by these crops. Zink and Davis (1951) observed no appreciable yield increase or significant delay in maturity when up to 180 pounds of nitrogen was applied to cantaloupes, although most of the nitrogen treatments reduced the number of cull fruit. Carolus and Lorenz (1938; found that both manure and potassium favored earliness in muskmelons. Pocash applications of 100 pounds per acre gave good yields, but applications of 200 pounds depressed yields. In Delaware, Rahn (1946) reported that up to 10 tons of stable or mushroom manure increased the yield of muskmelons during a year of low rainfall, but was no more valuable than commercial fertilizer during a year of adequate rainfall. The value of manure during a dry year was attributed to increased soil waterholding capacity* In a ten-year experiment, Morgan and Jacobson (1940) studying the effects of fertilizer, manure, and cover crops on the production of fifteen vegetable crops found that manure was more valuable during the drier seasons. Summer squash yields were increased with additional increments of nitrogen up to 135 pounds per acre. All crops generally benefitted from an application of one half of the nitrogen to the rye cover crop. Liming to a soil pH of 6.2 was beneficial to most crops tested including squash and slicing cucumbers. The literature indicates wide variations in fertilizer recommendations and responses of cucumbers and other cucurbits to the various nutrients. Many workers have not filly interpreted their data on the basis of such factors as temperature, moisture, soil type, organic matter, rate and placement of fertilizer, and time of fertilizer application. As a result, there is no general agreement as to the conditions necessary for satisfactory yields of high quality fruit. Vegetative Growth. Flowering and Fruiting Such factors as nutrition, photoperiod, temperature and pollination have been reported to affect vegetative growth, flowering and fruiting of cucumbers. Dearborn (1936) found that high nitrogen increased vegetative growth, fruit size number, and the percentage of female flowers produced in slicing cucumbers. Also, plants grown under the high nitrogen level contained more total nitrogen than plants with the low nitrogen treatment. Low nitrogen plants had stiff woody stems and pale green foliage and fruits that were of poor quality with marked curving and blossom end constrictions. It was concluded that a relatively high nitrogen level is essential for the production of maximum yields of highly-colored, straight, well-shaped fruit. Tiedjens (1928) reporting the effect of nitrogen level and pollination on fruit shape found that flowers pollinated at anthesis produced 100 percent normal fruits under high nitrogen conditions, but only 62 percent normal fruits when low nitrogen conditions prevailed. When pollination was delayed 24 hours after anthesis, all fruits produced with the low nitrogen treatment were wasped (constricted in the middle) severely enough to be classed as seconds or culls. Delayed pollination with high nitrogen resulted in fruits that although slightly wasped were still classed as first grade fruit. Vaile (1938, 1942) reported that the set and number of marketable cucumber fruit were greater under high than under low nutrient conditions, and that high nutrition levels were necessary for proper development of the pistil of cucumber flowers and the subsequent setting of normal fruit. The levels of nutrition apparently did not affect staminate flowers but a greater proportion of female flowers were formed. Dearborn (1936) also observed that proportionally more pistillate flowers were produced with high nitrogen levels. Bodinkov (1944) reported that nitrogen was the most limiting nutrient during growth and flowering, while potassium became the dominant element during fruit formation; and observed that mineral nutrition Influences the sex ratio of cucumbers. Reynolds and Stark (1953) observed that dry weight of cucumber plants grown in sand cultures increased with each increase in nitrogen level but that fruits were most numerous at the medium level. Mhen the magnesium level was varied in sand culture experiments, vegetative growth was greater at the medium level, however, fruit production was highest and the percentage of malformed fruits lowest at the highest level. Magnesium deficiency symptoms were intensified by additions of potassium if magnesium was low but a combination of high magnesium and high potassium resulted in normal growth and fruiting. In pollination studies, Tiedjens (1928) found that the number of seeds produced in cucumber fruits did not exceed the number of pollen grains applied to the stigma but that the placement of pollen on the stigmatic lobes did not affect seed location in the fruit. He reported there was no correlation between number of seeds contained by a fruit and the shape of that fruit. Fruits containing two seeds were as well shaped as those containing 200 seeds. However, in the same report, he stated that uneven distribution of seed necessarily produces irregularity shaped fruit. Unpublished data (Ries, 1954) indicated that some environmental factor or factors affected the length to diameter ratio of pickling cucumbers. He observed that the same variety grown at locations 60 to 100 miles apart often varied as much in length to diameter ratio as two different varieties grown at the same location. Seaton, et al (1936) demonstrated the necessity of adequate pollination in producing large numbers of well formed cucumbers and found that plants enclosed in screen-wire cages without insects produced very few fruits, nearly all of which were malformed. Seaton and Kremer (1941) found that under normal conditions, flower opening occurred at 58 to 60°F*, and anther dehiscense, nectar secretion, and bee activity occurred above 62°F, and pollen tube developed at temperatures above 70°F. Under optimum conditions, four days were required for the pollen grains to germinate and send tubes to the base of the fruit with the fruit reaching pickling size three to six days later. McCollum (1934) observed that elongation of the central axis of cucumber plants ceased when the developing fruit was about four inches in length and that the growing region of the plant became a cluster of female buds which were yellow and abortive. Fruit from flowers had already been pollinated assumed a dormant condition, but continued growth within three days after the large fruit was removed. Conversely, fruit formed on the unpollinated check plants did not develop seeds or exert any inhibiting effect on the vegetative growth or smaller developing fruits. Dearborn (1936) also reported normal fruiting decreased rate of linear growth of cucumber plants as compared to those from which the blossoms had been removed. Hall (1949) observed that the peak of flower production by gherkins occurred 15 days earlier under an eight hour photoperiod than under a 16 hour photoperiod. Short day plants also produced a greater number of nodes and leaves than did the long day plants. production of large root systems. Long days favored the Stem elongation was greater in the long day plants when the nitrogen level was high, but under conditions of low nitrogen, stem elongation was promoted by the short photoperiod. Danielson (1944) reported maximum stem elongation occurred at an eighthour photoperiod and was retarded at a 16 hour photoperiod. However, total dry weight of plants was less for the shorter photoperiod. Dearborn (1936) reported that slicing cucumbers and Hall (1949) that gherkins produced a greater proportion of pistillate flowers under conditions of high nitrogen. The medium rate of nitrogen that was employed by Reynolds and Stark (1953) caused earliest production of pistillate flowers in pickling cucumbers. Tiedjens (1926) observed that abundant light was favorable to the development of staminate flowers, while reduced light caused increased production of pistillate flowers. A report by Nitsch, at al (1952) indicated that both pickling cucumbers and small gherkins tended to produce staminate flowers under conditions of high temperatures and long days and pistillate flowers at low temperatures and short days. Research conducted by Hillyer (1956) indicated that although low temperatures and short days caused narrow staminatepistillate ratios in cucurbits, the same effect could be achieved by by applications of maleic hydrazide. Wei and Scheffer (1951) observed that cucumber bacterial wilt was favored by conditions of low nitrogen and high potassium. McClure and Robbins (1942) found that cucumber seedlings grown with high nitrogen levels tended to be more resistant to damping-off than seedlings that were grown with low nitrogen. Resistance to this disease was attributed to the greater rate of cell lignification brought about by adequate nitrogen. It is apparent that the vegetative growth, flower sex ratio, and fruiting pattern of the cucumber can be varied by varying the environmental conditions under vfoich it is grown* Chemical Composition of Plants and Fruits Chemical analyses of cucumber and other cucurbit vines, fruit, and seed by Wilkins (1917) shows that calcium was 10 times as high in the vines as in the fruit, and was apparently accumulated as the growing season progressed. Magnesium was two to three times as high in vines as in fruit and was slightly higher in cantaloupe seeds than in cantaloupe flesh. Phosphorus content was slightly higher in the fruit than in the vines but nitrogen and potassium did not vary appreciably between vines and fruit. Friedrich and Schmidt (1954) analyzed cucumber plants at 10 day intervals for nitrogen, phosphorus, potassium, calcium, and magnesium, and found that the leaves had an especially high calcium content, that nitrogen was stored in leaves mainly as protein, but that fast growing organs such as fruit contained a high percentage of soluble nitrogen. Chemical composition of plants grown in nutrient solution did not differ materially from those grown in soil; although the mineral content of the nutrient solution was much higher than that of the soil. was the same in both cases. Water content They noted a large increase in nutrient uptake during flowering and fruiting. Carolus and Brown (1935) found that fruits from cucumber plants which had been fertilized with magnesium contained 36 percent more MgO than plants not receiving magnesium. Carolus (1934) reported that magnesium oxide was increased by 100 percent in stems and 600 percent in leaves of plants by additions of magnesium to the soil. Windham (1953) observed that soil applications of nagnesium caused significant increases in magnesium content and reductions in potassium content of pickling cucumber vines. Campbell (1953) found that the calcium level in pickling cucumber vines was not changed by soil applications of calcium, potash or sodium, however the potassium level was increased by application of potash, and the sodium level was increased by the application of either potash or sodium. Reynolds (1954) analyzed pickling cucumber leaves and fruits which / had been grown with varying levels of soil nitrogen, phosphorus, potassium, calcium, and magnesium and observed significant differences due to treatment in leaf phosphorus, potassium, magnesium and fruit calcium. There were no significant differences in nitrogen, either in leaves or fruit. The data of Vogele and Weber (1932) indicate potassium is required by greenhouse cucumbers in increasingly greater amounts as growth continues. They observed that maximum requirements for nitrogen by this crop occurred from the 31st to 44th day after seeding, maximum requirements for phosphorus occurred between the 45th and 58th day, and lime was needed in greatest quantities between the 17th and 44th day after seeding. EXPERIMENTAL OBJECTIVES A review of literature pertaining to the effects of environmental factors on pickling cucumbers indicated no general agreement as to the conditions necessary for satisfactory yields of high quality fruit. In many cases, workers have apparently not fully evaluated their data from the standpoint of variations in temperature, light, moisture, rate and placement of fertilizer, soil type and organic matter. Therefore, these investigations were initiated to study the effects of several of the above factors on pickling cucumbers by: l) a greenhouse study involving all combinations of two night temperatures, two daylengths, and two nitrogen levels, 2) a field study using three rates of a complete fertilizer and three methods of placement, 3) a- field experiment interacting nine combinations of rate and time of nitrogen application with two rates of potash, 4) a survey of pickling cucumber fields to associate the levels of five nutrient elements in cucumber petioles at three stages of growth with yield and quality of pickling cucumbers. THE EFFECTS OF NIGHT TEMPERATURE, DAYLENGTH AND NITROGEN LEVEL During the late winter and early spring of 1955 a greenhouse study was conducted to determine the effects of temperature, daylength, and nitrogen level upon the growth habits of two varieties of pickling cucumbers. Materials and Methods Cucumber seeds were sown in flats of vermiculite on February 5* and ten days later, uniform seedlings were transplanted into 4-inch pots. On March 5* when the seedlings has reached a stage where the second true leaf was expanding, they were transplanted into ten inch pots containing a mixture of fertile loam soil and barnyard manure and placed at two night temperatures. Nitrogen was applied weekly to the high nitrogen series and fluorescent lights were used to extend the light period, for the long day series. The factors studied were as follows: 1. Two levels of nitrogen High - supplemental nitrogen at the rate of one gram of ammonium nitrate per plant applied in a water solution weekly for seven weeks. Low - no additional nitrogen applied. 2. Two night temperatures 60°F. and 70°F. 3. Two daylengths Long day - natural daylength plus artificial illumination from fluorescent lights for a total of fifteen hours. Short day - natural daylength which averaged about eleven hours during the experiment. 4* Two varieties, Wisconsin SR-6 and Ohio MR-25. The plants were supported by lengths of binder twine which was suspended from wires approximately four feet above the level of the soil in the pot. All pollination of flowers was done by hand between the hours of 10 a.m. and 1 p.m. Results and Discussion Plant growth was slower and intemodes were shorter on plants in the cool than in the warm house. Flowering was delayed approximately ten days and fruit production eleven days under cool temperature conditions. Plants growing under conditions of low nitrogen developed typical nitrogen deficiency symptoms with pale green yellowish tinged foliage, and stiff, woody steins. These symptoms were visible in the warm house by April 4, two months after seeding but did not appear in the cool house until two weeks later. Plants grown under high nitrogen conditions were dark-green and succulent* Yields The cucumbers were harvested at intervals of five or six days, depending upon rapidity of growth. A few of the fruits reached the number 3 (lj to 2 inches in diameter) pickling size. The straight, well-shaped fruits were classified as marketable, and those with curving, constrictions, or bulges as culls. The number of marketable fruit per plant and the percentage marketable for the various treatments were recorded and the data analyzed statistically. Approximately three times as many marketable fruit were produced by the high nitrogen as by the low nitrogen plants (Table I). Fruits from Table I. The effect of daylength and nitrogen level on the average yield of marketable fruit.i/ Nitrogen level Daylength Marketable fruit (number per plant) Long 10.42* 88.85 Short 12.96 33.58 11.69* 86.22* Percent of total yield^/ High Nitrogen Avg# Long 4.53 72.17 Short 4.67 79.30 4.63 75.74 Low Nitrogen Avg. *F values for the effects of nitrogen level and daylength x nitrogen on marketable fruit, and nitrogen level on percent of total fruit significant at 5$ level. 1/ Mean of 24 plants, ~ 2/ Difference between each value and 100$ represents culls. the low nitrogen plants were lighter green than from the high nitrogen plants. The largest number of marketable fruit were produced by plants receiving high nitrogen and grown under short day conditions, however the highest percentage of marketable fruit was produced under long day conditions. Since only one house was available for each temperature, there was no direct statistical test for the independent effect of temperature. However, interaction of temperature with daylength and nitrogen level (Table II), indicate that the highest yields were produced with high nitrogen in the warmer house and that neither temperature nor daylength affected the yield of the low nitrogen plants. Therefore, nitrogen level was the most limiting factor of the experiment, as far as yields were concerned. The lowest relative yields were produced under the combined effects of low nitrogen, low temperature, and long day, and the highest relative yields were produced with high nitrogen under the same low temperature and long day conditions, again indicating the relative importance of nitrogen. Length to diameter ratio: Length to diameter ratios were calculated for all marketable fruit by dividing the diameter of each fruit into its length and the averages for the various treatments are presented in Tables III and IV. The high nitrogen level increased the length to diameter ratio of fruits of both varieties. Fruits produced under 70°F. night temperature conditions were relatively longer during the early harvest period, however fruits produced under 60°F. conditions were relatively longer during the late harvest period. The early harvest ■gw) -P XJ I —Q)I °Tt © o G © i—I bO r- •5 to CNi • UN CO co fr- crO• o CO a £ o PI on CN) i —• 1 CN Cv CM on • On O- On un , Cv“ C'- 1 —1 cv • nO nO 1 —1 • CO £> un NO ON , CM £>© fe rH 4b 3O s! c Co M * u\ CO — t " Ui N , o O i —1 On , £>CO C*N U* + CN) On £NNO • nO IN- UN UN • -©■ CO © $ I—I bO 4 a O PI CO CO • nO ON UN rH • Cn• CO nO on ON • o rH UO N c— C « i —i a © bO o u p *d * © 43 15) a © iH E? r** >s © x> -3 bO t o g 43 CO 3 r** © X* bO G O PI & * P h © & s © -p 43 bO © x J U O 43 co P O © Table "S rH II, The effect of night temperature, daylength and nitrogen level on the average number of % & * +5 j ©-i Ob lr •H © Si Eh © oI*. o c- • bo t> * Em O o vO ♦ bO > <© © i> & f $ © P o o © rH X) G © XJ M © s* © © > Ju s O © § p © © « C © p p • 9 •r\ a P $ rH © Ui 43 © O ©P o G > Em $ S? p H g ■Hi © G bn © © *H s; a Table XU. Length to diameter ratio of two varieties of pickling cucumbers as affected by nitrogen level. Nitrogen level Variety Wisconsin SR-6 Ohio MR-25 Mean High 2.66 2.84 2.75** Low 2.51 2.63 2.57 "X*F value significant at 1% level Table17. Differences in length to diameter ratio of pickling cucumbers grown at different temperatures for different harvest periods'5** Harvest period Night temperature 70°F. 60°F. Early 2.66 2.71 Late 2.52 2.82 **F value for interaction significant at 1% level period consisted of the first four pickings and the late harvest period consisted of the last three pickings. The daylengths had no effect on length to diameter ratio of the fruit. Flower sex ratio: Both staminate and pistillate flower numbers were recorded daily for 24 days, after flowers were being produced in abundance, and the staminate/pistillate flower ratios calculated for each treatment. Table Va shows that relatively more pistillate flowers were produced by the high than by the low nitrogen plants. Of the factors studied night temperature was the most influencial on production of pistillate flowers. Although there was no statistical test for the independent effect of temperature, data in Table Vb show that relatively more pistillate flowers were produced under the cool than under the warm temperature. With high nitrogen the warm temperature resulted in the largest staminate flower production per plant. On the other hand, more pistillate flowers per plant were produced with high nitrogen under the cool conditions. In this connection it should be pointed out that pistillate flowers appeared in the cool house two days before staminate flowers and that staminate flowers appeared in the warm house seven days before any pistillate flowers were evident. The flowering behavior of both varieties was similar and the sex ratio was not influenced by daylength. It was observed that the cooler temperature tended to reduce calyx size and increase corolla size of both staminate and pistillate flowers. Although plants grown with the cool night temperatures produced more pistillate flowers, the highest yielding plants were grown with high nitrogen in the warm house, indicating that the warm temperature was Table Va> Average flower numbers and staminate-pistillate flower ratios produced by greenhouse pickling cucumbers over a 24 day period as affected by the various treatments, l/ Nitrogen level Number of flowers per plant Staminate Pistillate Staminate Pistillate ratio^ High 84.08 12.46 6.75 Low 67.20 7.19 9.35 value significant at l;o level 1/ Mean of 48 plants. Table Vb. Night Temperature Nitrogen Level Number of flowers per plant Staminate Pistillate Staminate Pistillate ratio: High 122.62 10.17 12.06 Low 98.20 4.92 19.96 High 45.54 14.74 3.09 Low 36.21 9.46 3.83 70 F. 60°F. value for interaction significant at 1 % level 1/ Mean of 24 plants. favorable for fruit set. A larger percentage of marketable fruit were produced in the warm house, suggesting that the faster rate of growth was more conducive to well shaped fruit than the slower growth rate in the cool house* Large length to diameter ratios of fruit indicate that the cell elongation was faster than cell width increase. Since larger length to diameter ratios were produced under high nitrogen and cool temperature conditions, it appears that these conditions were favorable for cell elongation. THE INFLUENCE OF FERTILIZER TREATMENTS ON YIELD AND QUALITY An experiment was conducted at Mason, Michigan in cooperation with the H. W. Madison Company to study the effects of rate and placement of a complete fertilizer on yield and quality of two pickling cucumber varieties* A second experiment was conducted concurrently in the same field using time and rate of nitrogen application and rate of potash as variables. Soil tests indicated that the field was initially low in fertility (seven pounds per acre of nitrate nitrogen, 53 pounds of potash, and three pounds of phosphoric acid) with a pH of 5*8. Materials and Methods Each experiment consisted of 36 plots arranged in a replicated split-plot factorial. five feet apart. Each plot consisted of four 40 foot rows spaced The cucumbers were seeded June 10, with a Palsgrove precision planter with fertilizer placement attachments, and except for the factors under investigation, accepted cultural practices were followed. The cucumbers were Jmrvested twice weekly from July 28 to August 30, for a total of ten pickings by labor employed by the cooperating company. The cucumbers were separated into the following grades: No. 1, up to 1 1/16 inches in diameter No. 2, 1 l/l6 to lj inches in diameter No. 3, ij to 2 inches in diameter Culls, fruits greater than 2 inches in diameter and fruits which were misshapen or otherwise undesirable. On August 1, and again on August 19, ten fruits of the No. 2 grade were randomly selected from each sub-plot for length to diameter ratio determinations. After the last picking, stand counts were made for all plots. Fertilizer rate and placement: A 5-20-20 fertilizer was applied at the rate of 150, 300, and 600 pounds per acre broadcast, or at the rate of 100, 200, and 400 pounds per acre side-placed and under the row. Broad­ cast placement of fertilizer was accomplished by hand distribution followed by a light harrowing with a spring tooth harrow prior to seeding. The side-place application consisted of one band placed two inches to the side and one and one-half inches below the seed, the under-row application of a band one and one-half inches directly below the seed, both applied with the Palsgrove seeder during the seeding operation. The varieties Wisconsin SMR-12 and Wisconsin 70, both of which are resistant to scab and mosaic, were used. Rate of potash and time and rate of nitrogen: Two rates of potash, 50 and 100 pounds per acre were side-placed with the Palsgrove seeder. The 50 pound rate of potash was supplied in 200 pounds of 0-25-25 and the 100 pound rate was supplied by 400 pounds of 0-12^-25• Ammonium nitrate was side-placed at different rates at two times in a total of nine combinations indicated below in terms of pounds per acre of nitrogen. At seeding 0 15 45 0 15 45 0 15 45 At vining 0 0 0 15 15 15 45 45 45 Total 0 15 45 15 30 60 45 60 90 The variety Wisconsin SMR-12, which is resistant to both scab and mosaic, was used in this experiment. Results and Discussion The season, during vhich these experiments were conducted, was characterized by erratic rainfall and temperatures which averaged seven degrees above normal. Precipitation for June was 4*94 inches with 2.71 inches on June 7, for July it was 3-59 inches vdth 2.05 inches on July 15, and precipitation for August was 3*29 inches with 1.23 inches on August 30. Average maximum-minimum temperatures (degrees F.) for June were 77*2 - 55*9, July 89*5 - 66.0, and August 84.1 - 64.2. No irrigation facilities were available. Fertilizer rate and placement; The highest yield was produced by plants fertilized at the low rate (Table Via). The yield was reduced by the medium rate and further reduced by the high rate of fertilizer, which with the high rate is partially explainable in a reduction in the number of plants per plot. Apparently, the medium fertilizer rate although not reducing stand, resulted in Injury to the plants, asthe low early yields indicate the possibility of a temporary injury. On the basis of early relative yields (Table VIb), much ofthe advantage of the low as compared to the high rate offertilizer was gained during the early harvests. Relative yields for all three grades fertilized at the low rate were higher than the relative stand, indicating that the better stand was not entirely responsible for the higher yield. The yields of the crop with the medium fertilizer rate were relatively lower than the stand values for all grades indicating the possibility © P o Eh 'H O © •H ■CO ca * cucumber: CJs rH • rH CA Os 00 3 • Os © CA $ £l © cm o A CO © UA sO X) © O CM rH Q O rH ;3 ao HI a Q) a] © p ' Ch5 E°h P& os to CO ca cm Ed 3 oa © CA rS .© © P X) © xi o © © xj rH p © Os Os £h © £ x) 3 p ua OA C-* £> © vO sO X) p © <5 © -p P o o © "o rH CM ca C*— CM i —! a sO p o Eh CM CM i—I rH i—I © h± rH a a © P X) © © *H o 3 O O rH O O rH p © © % u rp O Ht A CA CA p o P Os CA i —I i—I i—I i—j CM O O ■8 Eh CM CA rH CM CM rH O O rH © oa O CM rH O O H © © -p © O- Eh CM t> - p Os UA p © CM © © Os -p 'd © Ht cd tH 00 -4 - N •H r—I CM -P P © P X) © •H Q -©■ CM © P ,0 Os CM fi o 19 © 4 *p © iH © £ a CM rH CA © (ij ua i —I sO CM O O i —l i —) © © OA OA P Eoh o CA p o Eh o t —i O CA CM rH O O rH CA rH CO O H O O H CA ca rH Q © r-i © > © © -P © CA CM X) H £ Os rH *H P C i—1 © rH © Otf Scvil A & 3 XI M > H © © © X ) iH © tJ A ua i —I i —I i —I Via. © <—I -P wH P ft © rH P 0 to Table X © Eh O CM CO CA sO PP P< O UA O Os o o CM rH OA i—I O i—I • a © -P Is 3 XX TS M bO £ • CO 3 I S o hH XX b£) •H 33 2/ ALL values based on percent of high fertilizer rate <0 -p O 13 Effect of fertilizer rate on stand, and yield of each grade of pickling 3 that the fruit iUlness of many of the surviving plants was reduced. Table Vila shows that side-placement was the best method of fertilizer application, and that under the row placement was the poorest. Apparently side-placement provides nutrients in close proximity to the young seedlings, yet far enough from their roots to prevent injury at germination. On the other hand, broadcast placement was less effective than side placement, probably because of the much greater area over which the fertilizer was distributed. These assumptions are supported by relative stand and yield values in comparison to under-row treatment (Table Vllb) , Relative early yields indicated that the plants made a more rapid grcwth with side-placement of fertilizer than with under-row treatment, probably due to a lack of injury during early plant development. With the exception of grade No. 1, broadcast placement influenced higher late than early yields, indicating a slower start due to the lack of an adequate quantity of immediately available fertilizer. Date in Table VIII show that side-placement of fertilizer at the low rate resulted in highest yields of both varieties. At the medium fertilizer rate, Wisconsin 70 produced the highest yield when the fertilizer was side-placed and the lowest yield when the fertilizer was placed under the row. On the other hand, Wisconsin SMR-12 produced the highest yield when the fertilizer was placed under the row and there was little difference between the other methods of placement at this rate. At the high fertilizer rate, the broadcast application was best for Wisconsin 70 whereas the side-placed application was best for Wisconsin SMR-12, suggesting that Wisconsin 70 was more sensitive than Wisconsin SMR-12 to fertilizer injury. In general the data suggest that Wisconsin • -p 0 UN O CO * ON H • UN ON ~4 o NO XS on ^3. ?H 5 "S on UN CM rH £ si nO © cd -P \ O O Eh XS sO C*** On NO o © 4 NO p ON rH •s EH 1—I © C"- © N CM 3-* X) S3 © 0 -4 vO -4 *H CM -4 CM © TJ t © O o 1 —I 1 —I «H *©H cd P • cd m rd cCM ON CM rH © O ed S3 -4 CO CM to UN nO *© H H © iH XS © © 0 cd H Pi 1 © Eh ■8 S UN © O P O X) P © Q XS p CO xt © O *H p CO pp 0 « • * a *a © o © H (H © 0 Q -P © © £ O cd © O XS P 1 © © © XS o> xs *H CO O P m P a t=> 2/ All values based on percent of under row placement • r—i Table Vila ON O rH H © O 1 4 . Effect of fertilizer placement on stand, and yield of each grade of pickling cucumber Eh xs% Table VELL Varietal difference in yield response to rate and placement of fertilizer 1/. ¥-70 WSMR-12 Placement Bu/Acre Bu/Acre Avg. Low (100) Under row 231 206 218 Low (150) Broadcast 176 271 224 Low (100) Side-place 256 299 276 Medium (200) Under row 196 242 220 Medium (300) Broadcast 220 203 212 Medium (200) Side-place 249 194 222 High (400) Under row 119 186 153 High (600) Broadcast 245 169 207 High (400) Side-place 195 210 203 Variety Avg. 210 220 Fertilizer Rate 2/ 1/ Averages from two plots, 2/ Rates listed are pounds per acre of 5-20-20, SMR-12 was also a better forager for nutrients than Wisconsin 70 when the supply of nutrients was low. Disregarding the factor of variety, lowest yields were produced on plots treated with under row application of fertilizer at the high rate, again indicating the sensitivity of pickling cucumbers to fertilizer injury. Graphical presentation of these data (Fig, l) indicate that the varieties did not respond in the same manner to rate and placement of fertilizer. In every case the response of Wisconsin 70 to the various treatments may be explained on the basis of sensitivity or a lack of foraging ability. For under row placement, the yields of this variety decreased with increased rates, but increased as broadcast applications of fertilizer were increased, indicating injury in the first instance and lack of foraging ability in the second instance. The response of Wisconsin SMR-12 to rate and placement of fertilizer is more difficult to explain. The yield of this variety was reduced by under the row placement of fertilizer at the high rate, indicating a degree of sensitivity, whereas the yields were reduced as broadcast applications were increased tfiich possibly indicates that Wisconsin SMR-12 was absorbing toxic quantities of nutrients. However, when all fertilizer placements at the medium and high rates are considered, there is no logical yield pattern of Wisconsin SMR-12. The 1955 season was characterized by high temperatures and erratic rainfall. Had irrigation facilities been available, it is probable that fertilizer injury would have been reduced and yields increased with increasing rates of fertilization. However, the general interpretation of the data on the basis of prevailing conditions must be that increasing T3 c? o 'C? nj rH (1> nJ •H p lace X’ OC -H "7 TV rate -J and CO response U 3 t— I •a 3 'x3 N3 in yie ld H> 0> nj o Tod j O £-. Q T? I’d rH 0*j <;Ki s roL|si^v| rates of fertilization resulted in an unbalanced or toxic condition* Table EC indicates that the length to diameter ratio of pickling cucumbers "was not influenced by placement or rate of fertilizer under the conditions of this experiment* Hate of potash and time and rate of nitrogen: Plots receiving 50 pounds produced higher yields of cucumbers than plots with 100 pounds of potash per acre (Table X). These data suggest that the high potash rate may have interfered with normal growth of the plants, although there was no reduction in plant numbers. The largest yield difference occurred in the No. 3 pickling size, indicating that fruits grew faster on the low than on the high potash plots. Yield data for cucumbers by grades as influenced by the various nitrogen-potash combinations (Table XI) were not statistically significant; the yield were extremely variable and no consistent pattern is observable, although yields were at least twice the state average of 93 bushels per acre for 1955. Length to diameter ratio values (not presented) showed no differences for any treatment, Results of a greenhouse study indicated that high nitrogen conditions favored high yields of fruits with large length to diameter ratios. Nitrogen was applied in weekly applications, beginning at the two-leaf stage of plant growth, which facilitated the use of very large amounts without apparent injury* This suggests that the total amount of nitrogen should be split in several applications throughout the growing season, rather than applying it all in one or two applications* Table IXo Length to diameter ratios of pickling cucumbers for various fertilizer treatments at two sampling dates (August 1 and August 1 9 ) ^ Fertilizer Rate Placement a/1 8/19 WSMR-*12 8/1 8/19 Low Broadcast 2.95 2.95 2.80 2.80 Low Side-placed 2.85 2.85 2.90 2.80 Low Under row 2.90 2.90 2.80 2.80 Medium Broadcast 3.00 2.90 2.80 2.80 Medium Side-placed 2.85 2.85 2.85 2.85 Medium Under row 2.90 2.95 2.90 2.85 High Broadcast 2.90 2.95 2.65 2.80 High Side-placed 2.70 2.95 2.80 2.85 High Under row 2.90 2.90 2.80 2.80 W-70 1/ Averages from 20 fruits Table X. The influence of rate of potash on the yields by grades of pickling cucumbers. 1/* Hate of Potash Stand plants/plot Grade 1 bu/acre Grade 2 bu/acre Grade 3 bu/acre Total bu/acre Low (50 lbs per acre ) 65 34 73 107 214 High (100 lbs per acre) 64 29 65 87 181 values for rate of potash, and rate of potash x pickling grade significant at 5% level. 1/ Averages from 18 plots* Table XI. . Average yields of pickling cucumbers by grades in bushels per acre from plots receiving various nitrogen and potash treatmentsi/ Potash Levels Pounds/acre of nitrogen 50 pounds of K^O 100 pounds of K^O Grades 2 3 Grades 2 3 Early Total 0 0 32 68 15 15 24 0 15 15 Total 1 111 211 34 76 51 63 138 31 43 86 123 252 30 33 66 93 45 45 44 98 0 45 31 15 60 45 45 1 Total Avg.* yield no 220 215 70 95 196 167 26 64 42 143 191 192 23 60 104 187 190 151 293 20 41 61 122 208 69 98 198 37 91 128 256 227 37 75 123 235 29 62 90 181 208 60 23 66 101 192 27 62 83 172 182 90 34 71 110 216 30 59 78 167 192 aThere was no significant difference between nitrogen treatments. 1/ Averages from two plots. SURVEY OF THE NUTRITIONAL STATUS OF PICKLING CUCUMBERS Materials and Methods A survey was conducted in 1956 to determine the nutritional status of pickling cucumbers at three stages during their fruiting period. Crops in a total of nineteen fields were evaluated: eight in Saginaw, five in Montcalm, three in Allegan, and one each in Van Buren, Kalamazoo, and Tuscola counties. A resume of past and current cultural practices was compiled for each field. Within each field, from two to six 25 foot single row plots, depending upon the size and other characteristics of the field, were selected as sampling areas from which cucumber petiole samples were taken. A composite soil sample was taken from the plow layer of each area for nutrient content and pH value determination. Cucumber petiole samples were collected at three dates during the season: just prior to the first harvest, at the peak of the season, and just before the last harvest in the fall. Each sample was composed of ten to twelve petioles of living uninjured tissue selected from the middle portion of randomly selected plants. At the second and third sampling dates, the middle of the plant was located by leaf characteristics. The tissue samples were extracted with 2% acetic acid and analyzed by methods similar to those outlined by Carolus (1938). Potassium was determined turbidimetrically on samples taken at the first date and with a Beckman Mo die B Flame Spectrophotometer on the second and third samples. At the seoond sampling date, several vine and fruit samples were collected for total analysis. The cucumbers were harvested commercially and yields reported for each field were obtained from the records of the companies with which the growers contracted Results Association of cultural practices with yield: Summarized data from the survey sheets are arranged in Table XII in order of yield. The fields size ranged from six to 34 acres, with three major varieties, Wisconsin SR-6, Wisconsin SMR-12, and Ohio MR—17 being represented. Seeding dates ranged from May 5, to June 18, with the median period from June 5 to June 7. The yields were quite varied from the different fields, but with one exception all were above the state average of 106 bushels per acre for 1956. to yield. The value per acre of fruit was generally proportional Seven of the twelve highest producing fields were irrigated, and although irrigation was relatively un-important due to rather welldistributed rainfall during the 1956 growing season. Average inches of rainfall for June, July and August respectively were 1.08, 2.43, and 2.43 for Allegan County; 2.80, 4*84 and 5.10 for Montcalm County; 1.19, 3.13, and 5.05 for Saginaw County. Fertilizer practices were quite varied and apparently no single analysis or rate was associated with high yield. Fresh tissue analysis: A summary of chemical analyses of cucumber petiole samples collected at three sampling dates are found in Table XIII. The data have been arranged according to yield with each figure representing an average of from two to six samples, depending upon the size and other characteristics of the field concerned. When individual fields are considered, large variations in the nutrient levels of the plants are Table XII* „ Summary of yield data and cultural practices for nineteen cucumber fields. Farm County Field Size (acres) Variety Seeding Date Yield Bu/Acre Value per Acre Value per Bushel 1 Van Burena 12 SMR-12 5-25 434 $661 $1.52 2 Montcalm8, 20 SR-6 6-5 405 535 1.32 3 Saginaw3 15 MR-17 6-5 396 415 1.05 4 Tuscola 7 MR-17 6-2 361 390 1.02 5 Saginaw 10 MR-17 5-30 356 359 1.00 6 Allegan 10 MR-17 5-25 316 416 1.32 7 Saginaw 25 MR-17 6-9 293 290 .99 a Montcalma 15 SMR-12 6-6 271 347 1.28 9 Montcalma 20 SR-6 5-5 266 309 1.16 10 Montcalm 10 SR-6 6-11 242 317 1.31 11 Allegan3 10 SMR-12 6-6 232 263 1.13 12 Allegan8, 30 MR-17 5-25 229 307 1.34 13 Saginaw 8 MR-17 6-1 214 244 1.14 14 Kalamazoo 34 MR-17 6-7 213 243 1.14 15 Montcalm 10 SR-6 5-12 187 246 1.32 16 Saginaw 6 MR-17 6-7 150 154 1.03 17 Saginaw 20 MR-17 6-18 116 130 1.12 18 Saginaw 19 MR-17 6-13 114 135 1.18 19 Saginaw 14 MR-17 6-9 38 40 1.05 aFarms equipped with irrigation facilities# Table XIX. contM Previous Crop Fertilizer Pounds per acre N P205 K20 Land idle - --- — - ------ 120 220 220 Potatoes 165 192 192 Rye & oats 125 80 80 Sweet c o m 64 84 84 Rye 30 120 120 Beans 16 64 64 Bone 48 48 48 Oats 23 90 90 Clover 38 150 150 Cucumbers 16 32 64 Rye 20 64 64 Beans 24 24 24 Ryec 21 84 42 Wheat 4 24 24 Ryec 8 32 32 Bye 0 0 0 Ryec 72 80 80 Potatoes*3 118 140 140 Rye 14 56 56 Cucumbers 20 80 80 Rye 108 104 104 Red.Beets 36 84 324 Rye 145 36 108 Sugar Beets 30 60 120 None 30 30 30 10 40 40 Bone 104 96 96 None 39 65 65 Clover Clover (lj tons/a of manure) Cover Crop Fertilizer for Cucumber Crop pounds per acre N P205 Rp Sugar Beets 90 160 160 None 25 34 34 Sugar Beets 25 100 100 None 20 80 40 Wheat 25 50 50 None 20 80 80 Corn 4 24 12 Bone 8 28 28 ^Potato crop received 20T/A of barnyard manure in addition to commercial fertilizer. cCover crops received approximately 200 pounds per acre of 4-16-16 or 5- 20- 20. a> ■p cd T3 9 •H H U \ O a f t c ^ ft UA I O O O U A U A U A U A U A O O U A Q U A O O C- 4 CM I C N U A r H r J M A ^ c M ^ O O A v O C M C M N O U A V A r-H 00 00 C ^ O p O t a t O C ^ C v“ O O C O N - 4 ' i A t O rH i rH rH rH ft ca a> a> M •H CM 00 O U O U A U A C M U A O U A - ^ - C M O UA Q - 4 0 A - 4 U A - 4 - 4 U A - u t 0 A 0 A C M CM U A - 4 - O A O A CM - 4 U A U A CM U A U A U D UA o UA e 6 iS H -4 W N { f t CA r - j -P 0 - 4 f t f (ft O O O U A U A CM O CM o - H tA -^ O tO tO C N rH fiO u tO H J C A O J H 1 I rH i—I i—I rH i rH rH rH i—( i—j -P cd to o \ a> i —I o *H -P a> ft Jh CM O A 0 0 CM U A O A CM rH rH rH UA O O O UA O UA O UA O CM r H i— I i— I CM i— f HO A)- f flAO°4iA«MM»^H4r|4 q - IftO O N U A tft-^ tU A C M C M C M U A - c rO N UA O OA rH rH CM O A r H S to a> £ a f t ft O f t f UA u a r H CM Ift UA UA OA | I I I O O O U A O u a O O O nO O O u a u a o U A - ^ - U A t f t O O C '- O O O N U O U A O N C M t ft if t E ft UA O O A C f t 0 0 CM s O r-H CMCM I f t CM U A { f t O A - 4 CM r H O A O A U A U A O A - 4 - 4 O A U A 4 CM a •rH •H tQ CO cd O O UA O A 4 a | O f t0^OCM r CM ft I I I O « A I A U A 4 C M O UA O O O UA O O CM U A CM i H CM U A c f t - < f C M O A U A O A { f t U A H l f t 4 r l CM CM r l O r H O A CM - 4 " O A O n bO cd d £3 » •P O O a a d £ •X -,A su +■■> C! '* 0.. c .. 4 -H ( 3> > 1 X * % \ v\ / A t: in ,1 ;. o 15 H x> O 4-^ t> r— i •V tu •^-0 -^S t- . Oi > LC-. O o . J O '' r-i uo i [ XIw ‘i od s t.j ed o -rn season in area B. Potassium content of the petiole samples was initially low, increased to the highest level at mid-season, then decreased by the end of the season* The calcium decreased from early to mid-season, then increased sharply on the last sampling date. In all cases magnesium levels increased markedly from early to late. Grouping of the data on the basis of yield also tended to minimize individual variations and give a reliable indication of nutrient levels and trends. Table X V shows average nutrient levels in cucumber petioles from three high, three medium, and three low yielding fields* The average values for the high yielding fields indicate that nitrogen and phosphorus values were well balanced throughout the season* Potassium increased sharply from the first to the second sampling date and was then maintained at a high level, whereas calcium was initially high, decreased at the second sampling, then increased at the final sampling date* sampling dates. The magnesium contents were highest in this group at all In the medium yielding group, nitrogen was very high and phosphorus low at all sampling dates. The highest calcium levels and lowest potassium levels also appear in this group* Data for the lowest yielding group show that nitrogen decreased markedly until an apparent deficiency resulted at the end of the season. Phosphorus, on the other hand, was deficient early but reached very high levels by the end of the season due to accumulation as a result of reduced growth due to nitrogen deficiency. The magnesium levels in this group were considerably lower at the last sampling date than in the other areas* Table XV. . The average levels of five nutrient elements found in cucumber petioles at three sampling dates from three high, three medium, and three low yielding fields Yield rank High Medium Low Avg. yield bu/acre 412 234 127 Value per bushel #1.20 1.30 1.11 N 03*“N ppm P ppm K ppm Ca ppm Mg ppm 1 932 59 2150 I960 128 2 432 98 5007 732 414 3 282 93 4926 1245 947 1 1407 32 2293 2065 86 2 1078 36 4894 2013 335 3 855 33 4285 2977 80S 1 840 14 3322 1723 73 2 363 52 4900 1807 347 3 178 147 4530 1538 578 Sampling date The relationships shown between the various nutrient levels of high yielding fields apparently characterize the nutrient status found associated with high yield (Fig. 3 ). The graph for the medium yielding fields show that a relatively more unbalanced condition existed between nitrogen and phosphorus than was observed in the high yielding plants, and that the calcium level was apparently too high in relation to potassium* Nitrogen was obviously deficient in the low yielding group, especially at the third sampling date which had resulted in a high accumulation of phosphorus. Nitrogen was the limiting nutrient in the low yielding group, and phosphorus in the medium yielding group and apparently potassium was not limiting for any group. Soil analyses: Analysis of soil samples from each of the fields surveyed indicate that 14 of the 19 fields were deficient in phosphorus (less than 10 pounds per acre), and that only two of the ten highest producing fields had sufficient phosphorus (Table XVI). Tests for potassium indicate that only seven of the fields had a sufficient supply (80 or more pounds per acre) of this element. Either the active test is not an adequate measure of these nutrients for cucumbers, or the cucumber is a farily efficient forager for phosphorus and potassium from reserve supplies. Values for calcium and magnesium are relatively indicative of the pH values and manganese was found only in soil samples from Montcalm and Kalamazoo counties. Arrangement of the soil test data on an area basis Table XVII shows that area A was deficient in both phosphorus and potassium, area B was deficient in phosphorus, and area C was deficient in potassium. The soil uoT'[TTm sqjced Table XVI.. Amounts of six nutrient elements in soil samples from nineteen fields. Data are arranged according to yield per acre of pickling cucumbers. Farm Soil Class pH NO3 p-if Pounds per acre Ca K* Mg Mi 1 Sandy loam 6.8 20 4 90 320 20 0 2 Sand to loam 5.3 75 6 117 320 20 6 3 Sandy loam 6.4 8 37 44 900 40 0 4 Clay loam 7.3 16 5 27 800 32 0 5 Loam 7.4 28 7 45 1200 44 0 6 Dark sand 7.1 0 10 34 800 24 0 7 Loam 7.6 16 5 14 1200 32 0 8 Sandy loam 5.5 0 5 76 320 8 16 9 Sandy loam 6.0 30 9 89 560 12 4 10 Sandy loam 6.0 5 5 36 707 1 2 11 Light sand 5.6 60 2 117 320 0 0 12 Dark sand 6.8 40 10 130 1000 8 0 13 Loam 7.5 80 6 27 1600 40 0 14 Clay loam 5.8 32 11 46 535 27 11 15 Sandy loam 6.2 200 13 124 800 40 4 16 Clay loam 7.8 16 5 21 1600 24 0 17 Clay loam 7.6 40 7 55 1600 32 0 18 Clay loam 7.3 28 21 65 1150 16 0 19 Sandy clay loam 7.7 28 22 82 1300 12 0 -^Active test soil -samples from t hree areasi/in Michigan pH Area HO3 - -p|/— 6.13 30 6.5 B 5.67 62 7-6 C 7.08 31 12.6 A 1/ Area ,, Founds ner acre Ca KSA 73 ,$8 . 39 Mg 161 ’ J 610 13 0 541 16 6*4 1321 33 0 A -1field in Van Buren and 3 fields in Allegan Co* B -5 fields in Montcalm Co* C -7 fields in Saginaw Co. 2/ Active test* samples from, area C had the highest pH, and highest amounts of calcium and magnesium. Manganese was found only in the lower pH soils in area B. In general the soil test data on the basis of the active test bear little relationship to cucumber productive ability. A reserve test for P and K might have shown a better relationship. Total analysis of cucumber vines and fruit; At the second sampling date, vine and fruit samples were collected for dry tissue analysis from fields 6 and 11 in Allegan county and 9 and 10 in Montcalm county and a vine sample was also collected from field 19 in Saginaw county. The total analyses of these samples on the dry weight basis are given in Table XVIII and indicate that nitrogen was approximately the same in fruit and vine, potassium and phosphorus were more concentrated in the fruit than in the vines, and magnesium was twice as high and calcium six times as high in the vines as in the fruit. 87 percent water. Fruits contained about 94 and vines about The vine sample from field 19 in Saginaw county contained less than half as much nitrogen and only two-thirds as much potassium as the average of the other samples but considerably more magnesium, indicating the possibility of a partial substitution of magnesium for potassium. The total quantity of five nutrients on a fresh weight basis in the vines as calculated from total analysis data is compared with the soluble level of the same nutrients in the petioles (Table XIX). Fresh petiole tissue is apparently a reliable index of total nitrogen, potassium and magnesium in the cucumber plant; however, there is very little correlation between total and soluble phosphorus or calcium. The values u 3 IH p cos ro H t oa 3 ! sO oa 4 Os oa Os CM ua 4 05 O CD O. s to & • S O J H CD •g CD O J H CD P« w •H o o o OS rco• o so• o CM 4 ua © O S* © Os Os • 1—1 £S• UA CO • oa oa oa PH • co CM 4 SO CO ua ua OS <2 OA • 4 03 © •5 !> © pH Q, Ef 01 rt CO CO CO OS CM • CO CO 1—1 oa . o o o CO * o o '! c * o CO OA UA CM o c- r C"* • OA OA CO • OA cS to 3• 4 o- 4 so CM CO oa oa oa oa sO UA CO vO ua C-- ua • CO • CM • OA Os ua oa • o 4 - o O o UA Os • OA OUA • 4 sO t> * OA O i—1 • OA UA CO ♦ OA 1 1 1 1 OA OA * O 2>• OA CM Os * OA CO • OA r H 4 OA Os • 4 CJ O •H -P ctf O O • Os o CO f IH & • o O S3 ■§ ® O J H a) 4 ua u\ Sh CD CH so ua to 1o c* OA PH • o to PH » so o o tj • CO CO o s£> M Os oa oa o EH • o oa . •H 4 sO Os • ua ft. CTj • CO CO s ■§ CD O » o 1 Os • OA r H \>> -P o o a a ) to © o M o © >» ■p 2 © to © o o s ■g 5to S a? o 11 © *H i —I P* *H o © CQ O u \ to CM 4 o I —I CM 4 u a oa CM no 0T\ UA 0 f- © & £p a U. O r*- O P< U3 to C". ON 4 o o O O UA l> UA M3 M3 oa & 3 a o o o o -4 O OA UA rH E h a Pi © i —I S ■a O © P o 3 P. •H to to 8 i —I UA O 43 00 •H % i —I P O Pi Pi XS to M3 M3 -4- 5 c r\ u a 4 © 33 o o n P o p 0i0 's XS p P P o *3 O p u a CO *H to 4P3 •H © -s 3 Or o3 d P P 3 £0- s ua ua 4 4 to UA 4 rH OA O OA O 4 O 0 M3 CM to (I) -8 1 ? p S4 o E-f § O O rH rH •4 4 a ■s a d o UA O UA O O P P 00 © M3 4 O OA O o t© a>. O to UA 4 O A 03 O ” 8 M O O n CM 4 oa cm O O i— 1P P O © i— 1 © © rH l> © © rH © i — tP P P © P •H © U ■H P (i P P P P P © P P P rH o O EH CO ^h |oj) for soluble potassium are higher than for total potassium, indicating that potassium is more concentrated in the petioles than in the plant as a whole. Discussion When interpreting the plant composition data it must be kept in mind that high yielding plants remove much larger quantities of nutrients from the soil than low yielding plants and that the nutrient content in soluble form may be a very small percentage of the total quantity in the plant. However, since the soluble portion is the fraction which is readily available to the plant for building more complex compounds, it may vary quite widely as compared to the total content, especially nitrogen and phosphorus. The levels of soluble nitrogen and phosphorus were more closely associated with yield than were calcium, potassium, and magnesium. Analysis of petiole samples from low yielding plants indicated low nitrogen levels, whereas plants of the medium yielding group were low in soluble phosphorus. In general, there appeared to be very little relationship between the amount of an element in the soil and the amount of that element found in cucumber petioles. The most consistent cultural practice associated with high yields was the use of cover crops. The organic matter that is incorporated into the soil viien cover crops are plowed down tends to improve moisture and aeration conditions of the soil, in addition to acting as a buffer against injurious concentrations of fertilizer salts. Based on nutrient composition of petioles from plants in the higher yielding fields, the range of soluble nutrients shown in Table XX may be considered as satisfactory for pickling cucumbers. Values for three sampling periods are shown because of seasonal variations in the nutrient levels* Table XX, Satisfactory range of soluble nutrient levels in cucumber petiole at three periods of the growing season.i/ Time of Sampling Nutrient Nitrate Nitrogen First Harvest PPm Mid-Season - ppm Last Harvest ppm . 800 - 1000 500 - 750 250 - 400 Phosphorus 60 - 75 75 - 100 90 - 125 Potassium 2000 - 3000 3500 - 5000 3500 - 5000 Calcium 1500 - 2000 800 - 1000 1500 - 2000 90 - 125 350 - 450 850 - 1000 Magne sium 1/ Data based on analysis of cucumber petioles from high yielding fields GENERAL DISCUSSION The cucumber is one of the most sensitive vegetable crops to environmental changes. In field nutritional work, it appears that response of this crop to such uncontrollable factors as temperature and light often overshadow the effects of nutritional factors. For example, in the greenhouse where light and temperature were controlled to a certain degree, high nitrogen and low temperature resulted in fruits with large length to diameter ratios. In a field study conducted in 1955 using high rates of nitrogen, length to diameter ratios were not affected, possibly indicating that the high temperatures (seven degrees above normal) which prevailed modified the effects of nitrogen. In the greenhouse, high nitrogen or low temperature favored the production of pistillate flowers, supporting the work of Dearborn (1936), Hall (1939)> NItsch, et al (1952) and Hillyer (1956), In a greenhouse experiment, weekly applications of one gram per plant of ammonium nitrate, applied in a water solution after the plants had reached two-leaf stage trippled yields of pickling cucumbers. Results of a survey conducted in 1956 indicated many growers produced excellent yields vhen as much as 100 pounds per acre of nitrogen was used. Although nitrogen levels as high as 90 pounds per acre showed no consistent effects on yields in a 1955 field study, it is believed that prevailing high temperatures and drought periods masked beneficial effects of nitrogen. It was shown that relatively high rates of fertilizer placed in close proximity to cucumber roots caused injury, probably due to excess soluble salts in the soil solution. In a test in which soil conductivity values were determined, Dunkle and Merkle (1943) found that cucumbers were also less tolerant than radishes, cabbage and corn to high soluble salts, A further indication of the sensitivity of cucumber roots is their wide acceptance as indicators of the behavior of growth regulating substances. The fertilizer requirement for satisfactory yields of pickling cucumbers has not been clearly established, probably because of the wide variety of conditions under which nutritional experiments have been conducted. Fertilizer recommendations have varied from 250 pounds per acre of 5*10-5 (Barnes, 1941) to 1000 pounds per acre of 6-8-4 (Lloyd and McCollum 1940). Results of experiments conducted by Reynolds (1954) on a fertile sandy loam soil showed no differential yield responses to varying levels of fertilizer, however excellent yields were obtained from all treatments. In the present investigation a field study conducted in 1955 indicated that a side-placed application of 100 pounds per acre of 5-20-20 resulted in the least injury and the highest average yield (276 bushels per acre), and that yields were actually decreased with increasing rates of fertilizer, presumably due to fertilizer injury. Although results of fertilizer experiments vary widely, calculations based on total composition values indicate that the vines and fruit of a 300 bushel per acre crop removed 65 pounds of N, 22 pounds of P 2O5 and 90 pounds of K2O. Additional allowances of fertilizer to compensate for nutrients lost to the plant through either soil fixation or leaching tend to place the nutritional requirement of this crop in a relatively high range. Comparisons of the current nutrient level in the plants from 19 fields with productivity indicated that nitrogen was most often the limiting nutrient, followed by phosphorus. In order to avoid injury from high rates of fertilizer, the following methods of application are suggested. All of the phosphorus, because of its low solubility and mobility in the soil, along with ten pounds per acre of nitrogen and potash could be side-placed at seeding to promote early plant growth. The balance of the nitrogen and potash could be side-placed or applied through irrigation in several subsequent appli­ cations. Fertilizer injury can be further minimized by the use of green manure crops to maintain the organic content of the soil. This will result in improved soil moisture and aeration, and in addition reduce the soluble salt concentration in the soil solution. Organic matter is also conducive to deep rooted plants vhich are able to withstand fairly long periods of drought. Much of the value of barnyard manure for the production of pickling cucumbers reported by H o y d and McCollum (1940), Ware, et al (1953), and others was probably due to its organic content. Results of a survey showed many factors are involved in the production of satisfactory cucumber yields of high quality. Apparently soil management, fertilizer application, control of insects, diseases and weeds, and harvesting factors all influence productivity. It is suggested that additional work should be done on fertilizer rate, placement and time of application, with special reference to nitrogen and potash. Possibly the practice of applying one-half or more of the nitrogen to the preceeding green manure crop (Morgan and Jacobson, 1940) should be investigated further. Because relatively little has been done on minor element nutrition of pickling cucumbers, additional studies along these lines would appear advisable. Basic studies relating to the influence of environmental factors at various stages of plant growth would also be very interesting* SUMMARY The effects of night temperature, daylength, and nitrogen level on pickling cucumbers were studied. Low night temperature (60°F.) favored large length to diameter fruit ratios, and the production of pistillate flowers, when compared to the high night temperature (70°F.). Plants receiving the high nitrogen level produced three times as many fruit as the low nitrogen plants. ratios. the H High nitrogen also increased length to diameter Plants grown at 70°F. night temperature produced more fruit at hour daylength than at the 15 hour daylength, while at 60°F. night temperature, plants produced more fruit under long day conditions. High rates of a complete fertilizer, particularily when placed two inches under the seed resulted in decreased stands and yields of the two varieties of pickling cucumbers. Highest yields of both varieties were produced on plots receiving 100 pounds per acre of 5-20-20 in a side-placed application. The variety SMR-12 produced markedly higher yields with the low broadcast fertilizer application and with the high under the row application than Wisconsin 70, indicating that Wisconsin SMR-12 probably had a better foraging ability and was less sensitive to fertilizer injury than Wisconsin 70. A site-placed application of 100 pounds per acre of potash caused a reduction in the yield of pickling cucumbers as compared to a 50 pound per acre rate. Nine treatment combinations of rate and time of nitrogen application superimposed on the potash treatments had no consistent effects on yield or length to diameter ratio of the fruits. A survey of 19 cucumber fields indicated a definite relationship between soluble nitrogen and phosphorus in fresh cucumber petioles. Phosphorus increased as nitrogen decreased through the season. relationship between potassium and calcium was also evident. A The most striking result of petiole analysis was the fact that magnesium increased sharply as the season progressed. High yields were associated with abundant soluble nitrogen and phosphorus. From this investigation it was concluded that the pickling cucumber is quite responsive to fertilizer but is easily injured by it. This would suggest that growing the crop on soils well supplied with organic matter and the use of irrigation and frequent applications of soluble fertilizers would be conducive to high yields. LITERATURE CITED Anderson, W. S. 1939* Better fertilization and varieties, needs of pickling cucumber industry. * 1941. ,.„* 1943* 355: 1940. Close spacing, medium fertilizer rate most Banadyga, A. A. Barnes, W. C. 62nd and 63rd Ann. Rpts. 1949* Cucumbers for pickles. Association. 1934. . 1941. Bushnell, p. 40. National Pickle Packers 47: S. C. 121-122. Cucumber fertilizer experiments. S. C. Ann. Rpt. 155-157. John. 1930. The relative response to fertilizer of cabbage, Proc. Amer* Soc. Hort. Sci. 515-519. . 1941. Fertilizers for early cabbage, tomatoes, cucumbers, and sweet corn* Campbell, 8, March. North Carolina Response to basic slag, lime, and potash. tomatoes, cucumbers, and sweet corn. 27: 6(3): Oak Park, 111. Agr. Exp. Sta. Ann. Rpt. 54: Miss. Farm Res. Agricultural research in North Carolina. Agr. Exp. Sta. 8, Jan. 1-17. profitable for pickling cucumbers. Anon. 2(1): Growing cucumbers for pickling in Mississippi. Miss. Agr. Exp. Sta. Bui. - Miss. Farm Res. J. D. Ohio Agr. Exp. Sta. Bui. 622. 1953* Differential cation absorption and yield response by vegetable crops grown at various levels of calcium, potassium and sodium. Carolus, R. L. Ph.D. Thesis. 1934. Michigan State College. 163 pages. Effects of magnesium deficiency in the soil on the yield, appearance, and composition of vegetable crops. Amer. Soc. Hort. Sci. 32: 610—614* Proc. Carolus, R. L. 193&* The use of rapid chemical plant nutrient tests in fertilizer deficiency diagnoses and vegetable crop research. Va. Truck Exp. Sta. Bui. 98. _____________ > and Brown, B. E. 1935* Magnesium deficiency I. The value of magnesium compounds in vegetable production in Virginia. Va. Truck Exp. Sta. Bui. 89. _____________ 9 and Lorenz, 0. A. 193&. The interrelation of manure, lime, and potash on the growth and maturity of the muskmelon. Amer. Soc. Hort. Sci. Comin, Donald. 1938* 36: 518-522. Early yields of selected truck crops as affected by fertilizer treatments. Proc. Amer. Soc. Hort. Sci. ____________ , and Bushnell, John. cucumbers, and sweet com. Cooper, J. fi. and Watts, V. M. 1928. ______________ and 1934. . 1940. crops in Arkansas. of the cucumber. Dearborn, R. B. Fertilizers for early cabbage, Fertilizers for cucumbers. 312: Ark. 45-46. Manure experiments with vegetable Ark. Exp. Sta. Bui. 1944. 35s 673-677. Ohio Agr. Exp. Sta. Bui. 420. Agr. Exp. Sta. 46th Ann. Ept. Bui. Danielson, L. L. Proc. 392. Effect of daylength on growth and reproduction 19 s 638-648. PI. Phys. 1936. Nitrogen nutrition and chemical composition in relation to growth and fruiting of the cucumber plant. Cornell Univ. Agr. Exp. Sta. Mem. 192. Dunkle, E. C. and Merkle, F. G. 1943. The conductivity of soil extracts in relation to germination and growth of certain crops. Sci. Soc. Amer. 8: 185-188# Proc. Soil Eisemnemger, W. S. and Kucinski, K. J. plants. 1939* Mass. Agr. Exp. Sta. Ann. Rpt. Friedrich, G* and Schmidt, G. 1954* Magnesium requirements of p. 10. Untersuchungen uber die Nahrstoffausnahme von Triebhausgurken in Wasserkulturen. (The absorption of nutrients by glasshouse cucumber in soilless culture). Arch. Gartenb. Hall, W. C. 1949. 2: 319-335. (Hort. Abst.) Effects of photoperiod and nitrogen supply on growth and reproduction in the gherkin. Hillyer, I. G. 1956. PI. Phys. 24: 753-769* Effect of growth substances on flowering of cucurbitaceous plants. Ph.D. Thesis. Michigan State University. 102 pages. Jacob, W. C. and White-Stevens, R. H. 1941* Studies in the minor element nutrition of vegetable crop plants II. The Interrelation of potash, boron, and magnesium upon the flavor and sugar content of melons. Proc. Amer. Soc. Hort. Sci. Lloyd, J. W. and McCollum, J. P. 1940. 39 : 369-374* Fertilizing onion sets, sweet com, cabbage and cucumbers in a four year rotation. Exp. Sta. Bui. 464: 111. Agr. 219-236. McClure, T. T. and Robbins, W. R. 1942. Resistance of cucumber seedlings to damping-off as related to age, season of year, and levels of nitrogen nutrition. McCollum, J. D. 1934* Bot. Gaz. 103: 684-697* Vegetative and reproductive responses associated with fruit development in the cucumber. Cornell Univ. Agr. Exp, Sta. Mem. 163. Magruder, Roy. in Ohio. 1923 . Observations on the effect of liming truck crops Proc. Amer. Soc. Hort. Sci. 29 : 175-179* Morgan, M. F. and Jacobson, H. G. M. 1940. Soil management for intensive, vegetable production on sandy Connecticut Valley land. Conn. Agr. Exp. Sta. Bui. 439. 557-590. Nitsch, J. P., E. B. Kartz, J. L. Liverman and F. W.Went. 1952. The development of sex expression in cucurbit flowers. Bot. 39: 32-43. Phillips, E. L. studied. Hahn, E. M. 1955* Spacing and rates of fertilization for cucumbers Miss. Farm Res. 1946. 18(4): 8, April. The influence of rainfall on the response of cantaloupes to manures and commercial fertilizers. Soc. Hort. Sci, Reynolds, C. W. Thesis. Amer. Jour. 47: 1954. Proc. Amer. 343-346. Studies with cucumbers for pickling. Univ. of Md. Ph.D. 153 pages. and Stark, F. C. 1953* Growth and fruiting responses of cucumbers to varying levels of Ca, K, Mg, and N in sand culture. Proc. Assoc, of So* Agr. Workers. Ries, S. K. 1 9 5 4 * 133* Length to diameter ratio of pickling cucumbers. Michigan State University. Rodnikov, N. I. 50: 1944. Unpublished data. The rate of maturity and the yield of cucumbers grown under glass and their relationship to mineral nutrition. Proc. Sci. Conf. Timirjazev Agr. Acad. pp 45—46* Seaton, H. L. 3-10 June. No. 1, (Hort* Abst. 16:39) and Kremer, J. C. factors on yield and _________ Hutson, R., 1941. Effects ofclimatological quality of cucumbers. and Muncie, J. H, cucumbers for pickling purposes. Canner 92(15): 22. 1936. Theproduction of Mich. Agr. Exp. Sta. Spec. Bui. 273. Tiedjens, V. A. 1926, Some observations on the response of greenhouse cucumber (Cucumis sativus) to certain environmental conditions. Proc. Amer. Soc. Hort. Sci. • 1928* 23: 184-189* The relation of environment to shape of fruit I*1 Cucumis sativus L* and its bearing on the genetic potentialities of the plants* Vaile, J* E* Jour* Agr. Res. 36: 795-809* 1938* Ark* Exp* Sta. 50th Ann. Rpt* Bui. 368: 82. . 1942. Ark. Exp. Sta. 53rd Ann. Rpt. Bui. 417: 28. Vogele, F. and Weber, S. 1932. Untersuchungen uber Umfang und Verlauf der Nahrstoffaufnahme, Substanzbildung und Stoffwanderung bei Treibgurke (Nutrient intake, body formation, and disposal of nutrients in cucumbers Under glass). 478-492. (Hort. Abst. Gartenbauwissenschaft 6: 2: 109). Ware, L. M., Isbell, C. L., Harris, H. and Johnson, W. A. Studies with pickling cucumbers in Alabama. 1953* Ala. Agr. Exp. Sta. Cir. 114* Wei, C. T. and Scheffer, R. P. 1951* Relation of host nutrition to the development of bacterial wilt of cucumber, and fusarial wilt of watermelon. Wilkins, L. K. Phytopath. 1917* 41:38 (Abstract). The high calcium content of seme cucurbit vines. N. J. Agr. Exp. Sta. Bui. 310: 1-20. Windham, S. L. 1953* Theinfluence of various levels of calcium, potassium and magnesium in the soil on the absorption and yield response to potassium and magnesium by 17 vegetable crops. Ph.D. Thesis. Michigan State College. 98 pages. Wittwer, S, H* and Tyson, J. 1950* Yields of pickling cucumbers as influenced by rates of fertilizer application, fertilizer placement, and nitrogen side dressing* Bui. 32: 535-539. Zink, F. W. and Davis, 0. N. Calif. Agr. Mich. Agr. Exp. Quart. 5(6): 9. 1951. Nitrogen on cantaloupes.