THE, QUALITY 0? THE RED SOUR-CHERRY?" LL77 » .(PRUNUS CERASUS L‘.VCV. ’ ‘MOMMDRE-zmcv') AND SOUR CHERRY f. if 3 I97}; jjf (jg: PRODUCTS, INFLUENCE!) ZBY Panama - ‘ _ - AND NiTROGEN APPLICATIONS, ..~: : ~ ’Dissertatiqn forlfhe- Degree _;ofyPh"L-i D. I j ’ 5 MICHIGAN STATE UNIVERSITY . __ - LOWELL HOWARD sass? : ' 1974. I}: -.. LIBRARy Michigan State University ‘ «\ ,0' L J ’1' K") ,‘ %’ .b y«:: L\. «\1 COT ‘3 I FEE 0 a 2003 :2) ABSTRACT THE QUALITY OF THE RED SOUR CHERRY (PRUNUS CERASUS L. CV. ”MONTMORENCY”) AND SOUR CHERRY PRODUCTS, INFLUENCED BY PESTICIDE AND NITROGEN APPLICATIONS by Lowell Howard Silsby Most commercially produced sour cherries are mechanically har- vested, and soaked in cold circulating water for refirming purposes prior to processing. They are pitted, frozen and stored, partially thawed, and manufactured into dessert items. In the last decade, fruit have been frequently considered too large and soft to retain their whole-fruit character during the pitting and manufacture into dessert items. The use of organic fungicides, and large amounts of nitrogen coupled with mechanical harvesting, are factors suspected of aggravating this problem. Since l9h0, organic fungicides, more effective for controlling cherry leaf spot (Coccomyces hiemaiis Higgins) and brown rot (Monilinia fructicoia Wint.), have superseded the more toxic copper fungicide com- pounds. Nitrogen applications to Michigan orchards have increased over the past 50 years, producing yield increases. A comparison of three fungicides, fixed copper, dodine, and Difoiatan, in combination with two levels of nitrogen was conducted in 2;\ Lowell Howard Siisby it. two commercial sour cherry areas of Western Michigan from l970 to l972. U A third area orchard compared fixed copper and dodine on two blocks of trees of different age. All cultural, harvesting and processing operations were under commercial conditions in cooperation with the area growers and processors. Pre-harvest measurements for fruit quality and leaf nitrogen content were taken annually. in l97l, treatment lots of mechanically harvested fruit were pitted, frozen and manufactured into canned pie- mix filling or unbaked frozen pies by commercial processing companies. Fungicides Pre-harvest fruit quality data over the three-year period, indicated copper sprayed fruit were smaller with increased red colora- tion and soluble solids, and were slightly more resistant to separa- tion from their stems. Copper-treated fruit were slightly firmer in one orchard in l97i. Firmness was not affected when averaged over all orchards and years. in graded raw fruit samples in i97i, copper sprayed fruit con- tained 2.82 more wind whip-limb rubbed fruit than dodine treated fruit. However, in the pitted fruit the dodine treatment scored U.S.D.A. grade ”C” because of a poor "freedom from defects“ score. A reduction in pie- mix red coloration for the copper treatment was the only effect in either product attributed to the fungicides. Nitrogen At the high nitrogen application rate, fruit removal force (FRF) was significantly higher in two orchards for i970 to l972. The other ~ Lowell Howard Sllsby pre-harvest fruit quality factors were not different. FRF in the third orchard for 1971 and 1972, was significantly lower for the high N plots, and the fruit were smaller with less color and soluble solids content. In 1971, fruit color was significantly reduced in the high nitrogen treatments, and was the only pre-harvest factor affected in the three orchards. Raw fruit grades were low due to wind whipped fruit, and the pitted product U.S.D.A. grade ”C” for both treatments reflected this. However, the defects in the pie-mix fruit were greatly reduced at the higher N level. Smaller fruit size in the frozen pie was the only other significant factor associated with the increased N applica- tion on the manufactured fruit products. Tree Age Younger-aged trees produced significantly smaller fruit with greater soluble solids content for the 1970 to 1972 period. In 1971, these trees had lower leaf N content and FRF, and the fruit were smaller with more ieachable color. They were not different in fruit firmness or soluble solids content. The younger trees graded significantly more raw fruit under U.S. #1 minimum color in 1971. The pitted product would have had a U.S.D.A. grade “A" for both age groups, if pits had not been present in the samples from the older trees. Pie-mix fruit from the younger trees were significantly smaller in size and had greater drained weight, although the frozen pie and 30-pound can drained weights did not agree. Pie-mix fruit from the young trees also had greater color and less defects. Lowell Howard Silsby Orchard and Season Significant variability existed between orchards and season for all pre-harvest measurements. Most of these measurements varied greatly between orchards in any one year. Many of the treatment results pro- duced in the pre-harvest fruit were either negated in the processed product or were inconsistent. This inconsistency of effects makes it appear that there may be differences between fungicides in relation- ship to quality of sour cherry fruit, but these differences are likely to be related to individual situations and not consistent for all sites and all years. THE QUALITY OF THE RED SOUR CHERRY (PRUNUS CERASUS L. CV. 'MONTMORENCY') AND SOUR CHERRY PRODUCTS, INFLUENCED BY PESTICIDE AND NITROGEN APPLICATIONS By Lowell Howard Silsby A DISSERTATION Submitted to Michigan State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Horticulture 197A ACKNOWLEDGMENTS The author would like to express his sincere appreciation to Dr. A. L. Kenworthy for his guidance and review in the course of this project and in preparation of the manuscript. Appreciation is expressed to Dr. Jerome Hull, Jr., Dr. Alan Jones, Dr. D. H. Dewey and Dr. C. L. Bedford for their suggestions in editing this report. This research was made possible thru the support of the Michigan Association of Cherry Producers and the assistance of selected growers and processors. The research was initiated by the late Dr. A. E. Mitchell. Appreciation is due the growers - Alton Wendzel and Rodney Winkei, Elwyn Oimstead and Roy Hackert, and Peter Morrison, for use of their orchards and help in spraying, fertilizing and harvesting. Thanks also to Coloma C00p., Mason County Packers, and Morgan McCool, Inc., for processing facilities; and to Chef Pierre, Inc., and Michigan Fruit Canners, Inc., for manufacturing facilities. I would also like to thank Dr. Charles Kesner for his cooperation; Dr. C. L. Bedford and his staff for their time and effort in collecting data and use of the M.S.U. Food Science laboratories; and a special note of thanks to the many graduate students and summer employees in the Department of Horticulture who helped collect and process the data over the three-year period. TABLE OF CONTENTS ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . TABLE OF CONTENTS . . . . . . . . . . . . . . . LIST OF TABLES . . . . . . . . . . . . . LIST OF APPENDIX TABLES . . . . . . . . . . . . . INTRODUCTION . . . . . . . . . . . . . . . . LITERATURE REVIEW . . . . . . . . . . . . . . . EXPERIMENTAL METHODS . . . . . . . . . . . . . . Orchards . . . . . Pre-harvest Measurements . Leaf Analysis . . . . . Harvesting-Processing . . . Frozen Cherry Pies and Canned Cherry Pie-Mix Filling (l97l) . . . . . . . . . . . . . Product Evaluation . . . . . . . . . . Statistical Analysis . . . . . . . . . . . . RESULTS Pre-harvest Sour Cherry Quality Results . . . . Influence of Orchard Location and Yearly Variation l970-I972 . . . . . . . . . . . . . Influence of Fungicide Chemicals in Orchards #2 and #3 - l970- 1972 . . . . . . . . Influence of Nitrogen Level in Orchards #2 and #3 - l970- l972 . . . . . . . . . . . . . Influence of Fungicide Chemicals in Orchards #l - 1970-1972. (Low nitrogen level plots; averaged across tree age plots) . . . . . . . . . Influence of Tree Age in Orchard #1 - l970-l972. (Low nitrogen level plots; averaged over copper and dodine treatments) . . . . . . . . . Influence of Nitrogen Levels in Orchard #1 - l97l 1972. (Averaged across fungicide and tree age plots) . . . . . . . . . . . . . . iii Page vii 11 ll 12 HI i5 i6 17 I8 18 18 21 23 23 27 27 II. Fruit Quality Factors of Canned Cherry Pie-Mix Filling and Frozen Cherry Pies for 1971 Influence of Orchard Location and Fungicide . Influence of Nitrogen Applications with Copper and Dodine Fungicides - Orchards #1, #3 - 1971 . . . . . Influence of Copper, Dodine and Difoiatan - Orchard #3 - 1971 . . #2 and Influence of Tree Age - Orchard #1 - 1971 III. Raw and Pitted Sour Cherry Grade Raw Product Grade . . Pitted Product Grade (U. S. D. A. Packout - 1971 . . . . . DISCUSSION . . . . . . . . . . . Fruit Removal Force (FRF) . . . . Fruit Firmness . . . . . . . . Fruit Size . . . . . . . . Fruit Color . . . . . . . Fruit Soluble Solids . . . . . . Fruit Drained Weight . . . . . . Fruit Defects . . . . . . . . Orchard and Season . . . . . . SUNMRY O I O O I O O O Fungicide Effects . . . . . . . Nitrogen Effects . . . . . . Tree Age Effects . . . . . . . Orchard and Season Effects . . . . LITERATURE CITED . . . . . . . . . APPENDIX . . . . . . . . . . . . iv Results - l97l Score) and Percent LIST OF TABLES Table l. 10. Influence of orchard location and year on leaf nitrogen and pre-harvest sour cherry quality factors (trees of similar age, c0pper-dodine-low N plots) . . . . . . . Influence of copper, dodine and Difoiatan fungicides on leaf nitrogen and pre-harvest sour cherry quality factors - Orchards #2 and #3 - 1970 to 1972. (Averaged across nitrogen levels) . . . . . . . . . . . . Influence of applied nitrogen on leaf nitrogen and pre- harvest sour cherry quality factors - Orchards #2 and #3 - 1970 to 1972 . . . . . . . . . . . . . . . . Influence of copper and dodine fungicides on leaf nitrogen and pre-harvest sour cherry quality factors - Orchard #1 - 1970 to I972 a a a o o a a o o a o o o o o 0 Influence of two orchard ages on leaf nitrogen and pre- harvest sour cherry quality factors - Orchard #1 - 1970 to 1972. (Low nitrogen plots) . . . . . . . . . . Influence of applied nitrogen on leaf nitrogen and pre- harvest sour cherry quality factors - Orchard #1 - '97] to 1972 o a o o a o o a a a o a a o o 0 Influence of orchard location with c0pper and dodine fungicides on two sour cherry products - Orchards #l, #2 and #3 - '97] o o o o o o o o o o o a o 0 Influence of nitrogen applications with c0pper and dodine fungicides on fruit quality factors of two sour cherry products - Orchards #l, #2 and #3 - 1971 . . Influence of copper, dodine and Difoiatan fungicides on fruit quality factors of two sour cherry products - orChard #3 - '97] o o o o o o a a o a o a o 0 Influence of tree age on fruit quality factors of two sour cherry products - Orchard #1 - 1971 . . . . . I9 22 24 25 28 29 32 3h 36 37 Table ll. 12. The influence of orchards, fungicides, nitrogen levels and tree age on the raw product inspection grade - 1971 . . . . . . . . . . . . . . . . 39 The influence of orchards, fungicides, nitrogen levels and tree age on the pitted product U.S.D.A. score and packout percentage - I971 . . . . . . . . #0 vi LIST OF APPENDIX TABLES Table A1. Influence of orchard locations on sour cherry pre-harvest measurements - I971 . . . . . . . A2. Influence of copper and dodine fungicides on sour cherry pre-harvest measurements - Orchards #1, #2 and #3 - I971 . . . . . . . . . . . . . A3. Influence of copper, dodine and Difoiatan on sour cherry pre-harvest measurements - Orchard #3 - 1971 Ah. Influence of nitrogen applications on sour cherry pre-harvest measurements - Orchards #1, #2 and #3 - I97] 0 O C O O O O O O O C O O O O 0 AS. Influence of tree age on sour cherry pre-harvest measurements - Orchard #1 - 1971 . . . . . . vii INTRODUCTION Prior to the introduction of mechanical harvesting, sour cherries were picked by hand into buckets and dumped into 30-pound wooden lugs. The lugs were placed in a shaded area until they were loaded on trucks for transport to the processor at the end of a working day. At the processing plant, the lugs of fruit were dumped into tanks of cold water to soak for several hours causing the fruit to become firm before pitting. It is estimated that more than 90% of Michigan's sour cherry crop is now harvested mechanically. The fruit are shaken from the tree and caught on either: a) a canvas-covered inclined frame on each side of the tree, with the fruit rolling toward a conveyor at the tree trunk, or b) a canvas curtain rolled out on the ground under the entire tree, with the fruit deposited onto a conveyor as the curtain is rewound after shaking. The fruit are elevated into a tank of cold water IO°-13°C (50°-55°F), and are rapidly cooled, usually at the farm, by flushing cold water through a pipe manifold system on the tank bottom. Each tank holds approximately 1000 pounds of fruit and arrives for processing h-ZH hours after harvest. Pitted fruit may be processed, canned or frozen. Frozen cherries remain in storage until sold. Often, second handlers partially or completely thaw the pitted fruit, mix it with other in- gredients, package, and refreeze it in a dessert ready-to-bake by the homemaker. The fruit are subjected to much handling, freezing and thawing which tend to reduce the integrity and character of the fruit in the final product. Since I9AO, organic fungicides have been introduced for control of cherry leaf spot (Coccomyces hiemaiis Higgins), and brown rot (Monilinia fructicola Wint.). These compounds have predominately replaced the copper and sulfur compounds used in spray programs. They offer eradicat've and residual control of leaf spot and/or brown rot, allow more latitude in timing applications after infection periods, and are less caustic to the leaves, tree, and fruit. Nitrogen application rates and sources have changed with time. In 1927, A. J. Rogers (27) recommended application of 0.82 pounds actual nitrogen per mature tree. Today, nitrogen applications are frequently based on the amount absorbed by the tree, as monitored by leaf tissue analysis. A leaf nitrogen range between 2.5% and 2.952 is considered ”normal” for sour cherry (15). If leaf nitrogen is less than 2.3%, an increase in a grower's usual nitrogen application is suggested. Actual grower usage on bearing trees may vary according to soil type, cultural methods, and age and vigor of the trees. Sour cherry plots under test at Michigan State University have received 1.6 to “.0 pounds of actual nitrogen per tree. Some Individuals associated with the cherry industry believe the change in spray programs, the use of increased amounts of nitrogen, and mechanical harvesting, have resulted in fruit less able to withstand the handling processes from tree to consumer. Growers have found these changes increased the effectiveness of disease control and yield of fruit, and decreased the dependence on a shrinking labor force. The purpose of these experiments was to monitor the effects of commercial applications in the orchard on the cherry fruit, as It passed through the commercial handling processes into the cherry dessert items. A comparison of three fungicide chemicals (fixed copper, dodine, Difoiatan), and two levels of applied nitrogen (NHhNo3)’ was used in the three cherry producing areas along Lake Michigan. The effect of these treatments on one orchard block containing two tree age groups was also investigated. Pre-harvest fruit quality effects were compared over the three years and between the three orchards. LITERATURE REVIEW Certain fungicide and insecticide sprays have been reported to alter the physiological responses of sour cherry trees and fruit. Johnsen (12) found sprays of benzene hexachloride (BHC) and Bordeaux on sour cherry leaves reduced the length of paliisade cells more than sprays of lime-sulfur and parathion. _This possibly resulted in reduc- tion of photosynthetic rates. Rasmussen (2A) found defoliation of sour cherry leaves to first occur on spurs of older wood, followed by younger wood spurs and then shoots. The concentration of Bordeaux had no constant relationship to the amount of defoliation. Higher concentrations resulted in less trunk diameter growth and larger yields. Fruit size was largest and soluble solids were lowest at the lowest concentrations of Bordeaux. Horsfall (11) reported that repeated sprays of Bordeaux reduced the photosynthetic rate of bean leaves, and increased transpiration thru the upper cuticle. Bordeaux increased the transpiration of leaves at night when stomates were closed. He theorized that lime- induced alkalinity could cause saponification of the cuticle and increase transpiration. Lime is combined with copper to produce a chemical amalgam which slowly releases the copper, decreasing the phytotoxic effect of soluble copper on plant cells. Martin and Somers (22) showed that leaves and the water-soluble acids associated with leaf waxes were capable of solubilizing copper from Bordeaux spray deposits. Guttation liquids and spore populations have also been linked to the release of ”fixed” copper. Martin and Somers concluded that the host plant plays the primary role in bringing about the liberation of copper-containing compounds. Somers and Richmond (29) found a small but significant amount of cOpper from a Burgundy mixture (washing soda + copper sulfate) could not be removed from broad bean leaves by acid washing, yet afforded no fungitoxic activity even though it was present on the leaf in concentrations up to 15 times greater than the minimum giving a reSponse to the pathogen in a bioassay. They suggest that the copper is adsorbed on the surface rather than absorbed into the leaf and that sorption occurs while the fungicide deposit is drying. Rasmussen (25) reported that sour cherry fruit size was 168-197 per pound with Bordeaux vs. 162 per pound with lime-sulfur spray treat- ments. Increasing concentrations of Bordeaux increased the fruit sol- uble solids content and resulted in darker colored fruit. During drought periods, Bordeaux sprayed leaves turned yellow, withered and died, while those treated with lime-sulfur remained green. In l9h8, Lewis and Groves (l9) wrote that sprays of Bordeaux injured and sometimes defoliated trees with high aphid infestations or trees in wet or abnormally dry weather. The fruit produced were small, dark red and acid, and shriveled badly during a long hot, dry harvest season, making them unfit for harvest. An increase in fruit soluble solids content could not be explained entirely on the comparative size of fruit, The percentage of total weight discarded as pits also increased. Small unit size, shriveling and loss in pitting offset the desirable increase in color and soluble solids. Fixed or "safened" capper was a less effective fungicide, but caused less leaf and fruit injury. However, deposition of this chemical in the stem cavity of the fruit caused some skin injury which was objectionable in the canned product. Dowax (a wax emlusion) and Fermate, both compared to Bordow (16), produced larger fruit with less soluble solids and lower drained weight in the hot packed product. A taste panel judged these fruit to be inferior because of pale color and insipid taste. In similar spray comparisons, Bedford (1) reported taste panel studies showed no preference for processed fruit from any one Spray treatment. Lyon (20) reported the use of nitrate nitrogen produced tree growth under sod culture nearly as large as on cultivated plots with- out added nitrogen. Kenworthy and Mitchell (13) reported that mulches, fertilizers or clean cultivation that promotes cherry tree vigor by making nutrients and moisture available, results in higher leaf N content and reduced fruit soluble solids. They stated that seasonal differences in environment vary the effect soil management practices have on soluble solids, so that one type of cover crop had no advantage over another. Kenworthy (14) in 195“, found sod plus a mulch resulted in fruit production, leaf composition and soil analysis that was either equal to or better than that obtained from clean cultivations without a mulch. Fruit Removal Force (FRF) Unrath (3A) suggested an FRF of 500 grams would appear to be the maximum for commercial mechanical harvesting. Cain (5) stated the percentage of a crop removed by shaking depends on the fruit location on the tree, and is controlled by the tree age, growth condition, variety and pruning. Conditions that produce fruit on the ends of willowy pendulous branches greatly increase the shaking time necessary for economic crop removal. This correspondingly increases the amount of bruising of the fruit. Under a standard shaking time of 3-5 seconds with a one-inch stroke and 900 cycles per minute, the most effective shaking force was equivalent to a direct pull force of 367 grams (0.81 lb.). He strongly advocated the use of a pull-force gauge to check fruit maturity before entering an orchard with mechanical harvesting equipment. Crocker (6) found high nitrogen decreased FRF in 1969 but not in 1970. Fruit Firmness McManus (23) felt “soft fruit'I may be caused by high or low rainfall, excessive fruit set, or a lack of a sufficient leaf-to-fruit ratio. Drake (7) attributed soft fruit to an excess in tree vigor. Crocker (6) found that applied nitrogen had no effect on fruit firmness in 1969 or 1970. Lawver (17) stated that maturation due to harvest dalays and/or temperatures above 32°C (90°F) may cause fruit softening. He reported that Ferbam treated pitted fruit tended to be ”somewhat softer" compared to copper sprayed fruit as measured on a shear press with the modified ”pin”-type shear cell. Fruit Size Bordeaux and fixed copper sprays have been reported to produce smaller fruit compared to other organic and inorganic fungicide com- pounds (2, 3, A, 16, 17, 30). Taylor (30) and Taylor and Mitchell (32), reported fruit size to be larger in one orchard and smaller in another for copper sprayed vs. Ferbam sprayed fruit. They summarized “... that under conditions of adequate rainfall and constant moderate tree vigor, the spray materials may not materially affect the average number of fruit per ASA grams." They did report that capper sprayed fruit became lighter in weight each succeeding year of treatment, but this could be countered thru increasing tree vigor by cultivation and fertili- zation of the orchard. Smith (28) found no increase in fruit size occurred by doubling the N applicationtate. The most significant fruit size increase occurred by changing from 500 lb. of 10-0-0 to 500 lb. of a lO-6-A fertilizer mixture. Crocker (6) stated high nitrogen levels may result in slightly smaller fruit than with low levels. Gardner (9) found more variation in fruit size between years than between nitrogen treatments, and that there was no close correla- tion between yield and fruit size. Heavily loaded trees were just as likely to produce large as small fruit. Taylor (30) found seasonal fruit size variations for any one orchard, were as great as variations resulting from spray treatments. Bedford (3) found over a 10-year period, that fruit size varied the greatest between two consecutive years (1958 - 102 and 1959 - 139 fruit per pound). Floate (8) stated the consumer evaluates a cherry pie by the number of fruit per pie rather than by weight or volume. He believed the most desirable fruit size was 118 to 130 per pound (130 to 1A3 per 500 grams). Fruit Color Fruit color increases have been reported for copper treated fruit (3, 10, 19, 25). Lawver (17) reported copper, actidione (Cycloheximide), and ferbam sprays did not affect raw fruit color, but Hartz (10) found canned fruit color for the actidione and copper sprayed fruit, was significantly better than for ferbam sprayed fruit. Crocker (6) found nitrogen levels had no effect on raw fruit color in his tests. Fruit Soluble Solids Soluble solids, along with fruit color, have generally been regarded as the best indices of fruit maturity (21). Soluble solids of cherry fruit have been reported to be increased by copper sprays (3, 10, 16, 17, 19, 25, 30, 32). However, the soluble solids of mature fruit will also continue to increase when harvesting is delayed (31). Seasonal variation and cultural practices that promote tree vigor, e.g., increased soil moisture and nitrogen supply, mulches and clean cultivation, reduce the soluble solids content of the fruit (6. 13). Fruit Drained Weigh£_ Bedford (2) found there was no correlation between soluble solids content of fresh or soaked cherries, and the drained weight of hot-packed fruit. Variations in drained weights between orchard loca- tions over several years appeared to be related to weather conditions during the growing season, in that higher than normal rainfall with 10 normal temperatures decreased drained weights. He concluded (3) that drained weight of canned cherries may or may not be affected by fruit maturity and that cultural and climatic conditions generally result in greater variation than spray materials. Hartz (10) found copper treated fruit higher in drained weight, soluble solids, color, and number of defects. He attributed the variation in fruit drained weight to yearly variation of a number of factors including rainfall, temperature conditions, size, firmness, soluble solids and sprays used. He reported an increase of 1% fruit soluble solids content yielded a 2% increase in canned fruit drained weight. This offset slightly, the lower yield, and rapid decline in yield of copper treated fruit as the harvesting season progressed. Crocker (6) found no effect of applied nitrogen on the drained weight or shear force of hot packed cherries. Fruit Defects Bedford (A) and Hartz (10) reported c0pper treated fruit com- tained more culls, which was made worse if harvest was delayed. The fruit were smaller in size and higher in drained weight; however, the increase in culls and small size offset the advantages of increased drained weight and yield. Lawver (17) found that higher color in more mature fruit masked detection of raw fruit defects, which became apparent in the processed hot-packed fruit. EXPERIMENTAL METHODS Orchards In 1970, a study was initiated to compare the effects of nitrogen applications and different fungicides on the red sour cherry (f:ggg§_ cerasus L.). Three orchard sites were chosen in the major production areas of Michigan. Orchard #1 was near Watervliet (Berrien County), Orchards #2 near Ludington (Mason County), and Orchard #3 near Williamsburg (Antrim County). Orchard #1 consisted of two adjacent blocks of bearing trees, one block l8-years old and the other 28-years old. Both were on a sandy- loam soil under clean cultivation. They received a broadcast application of A pounds ammonium nitrate per tree (1.3A lb. actual N) in 1970. In the two succeeding years, a portion of each age block received a second application of "low" and "high" amounts of ammonium nitrate: 1971, A lb. and 8 lb. (1.3A lb. and 2.68 lb. actual N); 1972, 6 lb. and 10 1b. (2.01 lb. and 3.35 lb. actual N). The nitrogen blocks were split so that fungicide sprays could be applied to trees at each nitrogen level. Fungicide treatments were fixed copper + lime (0.75 lb. copper + 3 lb. lime per 100 gal), and dodine (Cyprex) 65% WP at 0.5 lb. per 100 gal. Orchard #2 was a block of bearing 17-year-old-trees on sandy- loam soil under clean cultivation. It was split into three blocks, each receiving a fungicide treatment - fixed copper + lime, dodine or Difoiatan (1.5 pints of a A EC formulation per 100 gal). Each fungicide block was divided to receive ”low“ and "high" rates of ammonium nitrate: ll 12 1970, 0 lb. and A lb. (1.3A lb. actual N) per tree; 1971, 0 lb. and 6 1b. (2.01 lb. actual N) per tree; 1972, 6 lb. and 12 lb. (2.01 lb. and A.02 lb. actual N) per tree. Orchard #3 consisted of trees 22-years old on a clay-loam soil. The orchard was maintained in sod with herbicides used in the tree row for weed control. This orchard was also split into three blocks to receive the same fungicide treatments as Orchard #2, at two nitrogen levels. Ammonium nitrate levels were 0 and 5 pounds (1.75 lb. actual N) per tree each year and referred to as “low” and ”high", respectively. The total experimental comparisons to be studied were differences in fungicides, nitrogen applications, orchards, tree age, and year-to- year variability. All fungicide and nitrogen applications were made by the grower-cooperator at the rates indicated above. The "low" nitrogen application rate was that used by the grower to maintain the leaf nitrogen content within the ”normal“ range as established by the Leaf Analysis Laboratory at Michigan State University. Timing of pesticide cover sprays followed recommendation in the M.S.U. Fruit Spraying Calendar (33). Pre-Harvest Measurements Pre-harvest fruit quality measurements were taken in each treatment block one day before commercial harvest. Each of five trees were sampled by randomly selecting 20 representative fruits around the circumference at shoulder level. The following measure- ments were taken on these fruit: 1) Fruit removal force (FRF) - The grams of pull-force needed to remove the fruit from its stem as determined by use of 13 Hunter push-pull mechanical force gauge model LKG-ll fitted with a stainless steel claw (l/2-inch wide, l/32-inch thick, 3-inches long). A slot (3/16-inch wide) extended from the open end of the claw around the curve. To achieve fruit separation, the fruit stem was inserted in the slot, and the pull force exerted in the center of the curved claw. 2) Fruit firmness was measured in Durometer units, a scale reading of 100 equaling A.0 ounces of resistance. A Durometer (type 00)2 has a 3/32-inch spherical indentor pro- truding 2.5 mm from its faceplate. A cheek of a fruit is pressed against the indentor and a reading taken when the fruit rests against the faceplate. The indentor does not penetrate the fruit. Resistance of the fruit skin plus the underlying flesh reflects a measurement of firmness. 3) Fruit size was calculated as the number of fruit per 500 grams. A) Fruit color development was determined by the method employed by Unrath (3A). A 5/16-inch diameter fruit-skin plug was removed from a cheek of each of 20 fruit. The plugs were leached in 50 m1 of 0.5% oxalic acid for seven days at 7°C (A5°F). Absorbance (optical density) of the solution was 3 measured on a Beckman model B spectrophotometer at 515 nm. ‘Manufactured by: Hunter Spring Division, Ametek Inc., Lansdale, PA. Manufactured by: Shore Instrument 5 Mfg. Co., Inc., Jamaica, N.Y. Manufactured by: Beckman Instruments, Inc., Fullerton, California. 1A Absorbance of O and 1.0 equals light transmission of 100% and 10%, respectively. Three 20-fruit samples were visually compared to the U.S.D.A. No. 1 Minimum Color Standard for red sour cherries. The color was leached as outlined above and the color concentration determined. They averaged 0.325 absorbance. 5) Fruit soluble solids - Several fruit from each sample were squeezed in the fingers, and the expressed juice placed on the prism plate of a hand-held refractometer. The readings are percentage values of the soluble constitutents, primarily sugars, present in the fruit. Leaf Analysis Approximately 50 leaves were sampled, the day before harvest, from each of the trees selected for fruit pre-harvest measurements. Leaves were sampled from the mid-section of current season's growth at shoulder level from around each tree. Not more than two leaves were taken from any one shoot. They were analyzed for nitrogen content by the Gunning macro-Kjeldahl method (18). Harvesting;- Processjgg_ A sufficient number of trees were mechanically harvested in each plot, at each location, to obtain a minimum of 1800 pounds (two field tanks) of unpitted fruit. In Orchards #l and #3, the wing-type catch-frame harvester was used, while the roll-out curtain type was in Orchard #2. Harvest was conducted in the normal sequence of each 15 cooperator's harvesting Operation. All plots within an orchard were harvested within an 8-hour period, and the fruit cooled at the grower's cooling station for 6 to 18 hours before being processed. Each test lot was pitted and packed separately by a commercial processing com- pany near each location. A raw product grade determined by Michigan Department of Agriculture inspectors, and a pitted product grade determined by U.S.D.A. inspectors, were obtained for each test lot. The weight of fruit entering the pitting operation and the number of 30-pound 5+1 pack cans (25 lb. fruit + 5 1b. sugar) was recorded to determine the percentage yield for each treatment. Sixty cans per treatment were labeled and set aside for manufacture into frozen pies or pie-mix filling, and for other observations. Processing data include only that for 1971 on all but one sub-treatment lost at harvest. Frozen Cherry Pies and Canned Cherrngie-Mix Filling (1971) In 1971, each lot of sixty 30-pound cans of the 5+1 frozen pitted fruit was divided for manufacture into either unbaked frozen pies by Chef Pierre, Inc., Traverse City, Michigan, or into canned pie-mix filling by Michigan Fruit Canners, Inc., Benton Harbor, Michigan. As each lot was processed, random samples were taken for later evaluation. Two 30- pound cans of the 5+1 frozen pitted fruit were set aside for later laboratory examination. Frozen pie manufactured by Chef Pierre, began with thawing of the 30-pound cans of fruit. The juice was removed, mixed with filling ingredients, and heated. The fruit was added to the hot slurry, gently mixed for uniformity and measured volumetrically into the pie 16 shell and quick-frozen. The pies were the 10-inch "institutional size” (A6 02 minimum net weight) containing a minimum of 30 ounces of filling. The pies averaged 1 lb. of frozen cherries. The canned pie filling made by Michigan Fruit Canners, was manu- factured by thawing the 30-pound cans of fruit sufficiently to mechanically separate the fruit. The fruit were volumetrically placed in no. 2 cans. The drained juice was mixed with the filling ingredients, heated, and added to the can before closing and heat processing. The canned fruit filling contained a minimum of 21 ounces. Product Evaluation Two cans of 5+1 frozen pitted fruit from each treatment, were thawed at 18°C (65°F) ambient temperature for 18 hours, and the fruit drained weight determined. Frozen pies were warmed 1.5 to 2.0 hours to a filling temperature of -3°C to -2°C (26° to 28°F), before evaluation. Two random samples of pie filling and frozen pies from each treatment were evaluated for the following: 1) Net content by weight of the pie or the canned filling. 2) Fruit drained weight. The product contents were placed on a U.S. standard No. 8 circular screen and the sugar-starch filling washed away from the fruit by a stream of water for 2 minutes. The water was run at 20°C (68°F) with 60 Inches of head pressure to insure uniformity. The fruit were drained two minutes and weighed. 3) The percent of fruit in the product on a weight basis (fruit drained weight/net weight) to measure the portion of the pro- duct occupied by the fruit. A) 5) 6) 7) 8) 17 Fruit size as the number of fruit per ounce of fruit drained weight. Defective fruit as the percent, by count, of broken and wind whip-limb rubbed fruit. The Hunter Color Difference Meter“ L value measures the lightness of a surface and varies from 100 for a perfect white to zero for black. A product with a darker color would absorb more light producing a lower reading. Color redness - Hunter values La/L are zero for a sample, b the color will be grey and will lie on the black to white comtinuum. A plus value for La indicates redness and minus, greeness. A plus value for Lb indicates yellow- ness and minus, blueness. Increasing positive values of the proportion indicate a more intense red color. Fruit integrity was estimated by a subjective examination of the fruit for wholeness, and expressed as a percentage. Statistical Analysis An analysis of variance for all comparisons were run on the CDC 3600 computer at Michigan State University, and the average values for the treatments compared using Tukey's w-procedure. The statistical comparisons were made to segregate the errors when "true" randomization was not possible because of the mechanical equipment and the volume of fruit necessary in commercial processing- manufacturing facilities. “Hunterlab Model 025 Color and Color-Difference Meter manufactured by Hunter Associates Lab., Fairfax, VA. RESULTS 1. PRE-HARVEST SOUR CHERRY QUALITY RESULTS Tables 1 thru 6 summarize the pre-harvest measurement of fruit quality as influenced by the fungicide and nitrogen treatments, the orchard, and year-to-year variability. Orchard #1 received only the low rate of nitrogen in 1970, and did not include a Difoiatan fungicide treatment. Copper and dodine low nitrogen plots were compared so that the variation could be determined for the three orchards over the three years. Data from younger aged trees at Orchard #1 were used, so that comparison trees at each orchard were of similar age. The Split-plot analysis of all treatment combina- tions placed the non-controllable factors such as moisture, tem- perature, fruit maturity, and soil type into the differences between orchard locations and yearly variation. Influence of Orchard Location and Yearly Variation - 1970-1972. Table 1 presents the pre-harvest data for 1970-1972 at each orchard site for fungicides at the low level of applied nitrogen. The leaf-nitrogen content in the three orchards did not vary significantly. In the third year, the overall nitrogen value dropped significantly to 2.30 percent. Leaf nitrogen content of 2.18% at Orchard #2 in 1972, reflects the absence of nitrogen application the two previous years. Fruit removal force (FRF) was significantly higher at Orchard #2 than at Orchards #1 and #3. The FRF was greater in 1972 than in 1970 or 1971. In 1970, there were no differences between orchards. In 1971, 18 19 Table 1. Influence of orchard location and year on leaf nitrogen and pre-harvest sour cherry quality factors (trees of similar age, copper-dodine-low N plots). Year Orchard 1970 1971 1972 Average Leaf Nitrgggn (Z) 1 2.56 a** 2.37 ab 2.Al ab 2.A5 2 2.AA ab 2.55 a 2.18 b 2.39 3 2.A7 a 2.5A a 2.30 ab 2.AA Average 2.A9 a** 2fA9 a 2.30 b Fruit Removal Force - grams 1 220.8 bc 211.7 c 333.6 a 255.A b 2 251.7 bc 22A.2 bc 3AA.2 a** 273.3 a** _3, 227.0 bc 272.A b 270.9 b 256.7 b Average 233.1 b 236.1 b 316.2 a** Fruit Firmness (Durometer Units) 1 59.5 ab 56.6 cd 58.6 abc 58.2 a** 2 56.7 bcd 55.A de 57.5 abcd 56.5 b ,3 57.A abcd 53.3 e 60.2 a** 57.0 ab Average 57.8 a 55.1 b 58.7 a** Fruit Size_(no. per 500 g) I 1A5.5 152.6 138.2 IAS.5 a** 2 10A.A 129.3 100.1 111.3 b .3 102.6 129.0 111.7 11A.A b Average 117.5 b 137.0 a** 116.] b Fruit Color (Absorbance)I 1 1.05 de 2.38 a** 1.21 d 1.55 a** 2 1.1A d 2.09 b 1.13 d l.A5 a 43 0.82 e 1.A9i c 0.8A de 1.05 b Average 0.99 b 1.99 a** 1.06 b Fruit Solublg,Solids (z) 1 15.A b 15.7 b 18.3 a** 16.5 a** 2 15.A b 15.0 bc 13.9 bcd 1A.8 b 43 13.A cd 13.9 bcd 13.0 d 13.A b Averagg_ IA.8 1A.9 15.1 ** Average values followed by different letters differ significantly at the 12 level. * l at the 5% level. Average values followed by different letters differ significantly U.S.D.A. #1 Minimum color for red sour cherry a 0.325 absorbance at 515 nm. 20 FRF for Orchard #1 was significantly lower than for Orchard #3. Orchard #2 was intermediate and not different from the other orchards. In 1972, FRF values for Orchards #l and #2 were higher than Orchard #3, and were statistically similar. This indicates non-consistency between years and orchard sites. Pre-harvest fruit firmness comparisons show Orchard #1 was sig- nificantly higher in fruit firmness than Orchard #2, while firmness in Orchard #3 was intermediate and not statistically different from the other two values. In 1971, the fruit were less firm than in 1970 or 1972. The relative differences between orchards were not consistent for each year. Fruit size was consistently smaller in Orchard #1 than in Orchards #2 or #3. Orchards #2 and #3 showed no statistical difference in fruit size. Fruit were smallest in 1971. Orchard differences were consistent each year. Fruit color was similar for Orchards #1 and #2 and lowest for Orchard #3 in 1970 thru 1972. Low absorbance values indicate poor color development. All values were well above those of fruit selected to match the U.S.D.A. #1 minimum color standard for red sour cherries (0.325 absorbance). In 1971, fruit were significantly darker in color than in 1970 or 1972. In 1971, fruit color decreased significantly from Orchard #1 thru Orchard #3. The soluble solids content of fruit did not vary significantly over the three-year period. The highest values were from fruit in Orchard #1. Fruit from Orchard #3 had the lowest soluble solids content in each year, but did not differ statistically from Orchard #2 except in 1970. In 1971, none of the orchards differed significantly. 21 Influence of Fungicide Chemicals in Orchards #2 and #3 - 1970-1972. Table 2 shows the pre-harvest fruit measurements as affected by c0pper, dodine and Difoiatan for 1970-1972. Orchard #1 is described separately as it did not receive the Difoiatan fungicide, or the higher rate of nitrogen in 1970. Percent leaf nitrogen and fruit firmness were not affected by the fungicide used in the spray program. Fungicide spray effects were con- sistent in each year for percent leaf nitrogen, fruit firmness, fruit size and fruit soluble solids. Fruit removal force (FRF) was higher, over the three years, for the fungicide copper than for dodine. Difoiatan treated fruit were intermediate between and not different from copper or dodine FRF values. FRF in 1972, was significantly higher than the other two seasons. The interaction indicates that FRF between copper and the other fungicide chemicals was significant only in 1970. Fruit were significantly more resistant to removal in the Difoiatan treatments each year. Fruit firmness varied only between each season of test. Highest fruit firmness was in 1972 and lowest in 1971. Fruit size was significantly smaller for copper treated than Difoiatan treated fruit. Dodine sprayed trees produced fruit inter- mediate between and not different from the other fungicides. Fruit size was smaller in 1971 than in 1970 or 1972. Fruit color was significantly greater for copper than dodine or Difoiatan sparys, and was higher in 1971 than 1970 or 1972. The inter- active effect of fungicide and season shows that dodine and Difoiatan pro- duced varying amounts of fruit color each season in relation to the copper treatment which was consistently higher. 22 Table 2. Influence of copper, dodine and Difoiatan fungicides on leaf nitrogen and pre-harvest sour cherry quality factors - Orchards #2 and #3 - 1970 to 1972. (Averaged across nitrogen levels). Year Fuggjcide 1970 1971 1972 Average Leaf Nitrogen (2) copper 2.51 2.55 2.285 2.AA dodine 2.57 2.62 2.29 2.50 Difoiatan 2.52 2.58 2.28 2.A6 Average 2.53 a 2.58 a** 2.28 b Fruit Removal Force (grams) copper 262.A b 258.7 b 316.9 a 279.3 a** dodine 230.0 c 2A5.5 bc 305.0 a 260.2 b Difoiatan 230.] c 255.1 b 321.A a** 269.1 ab Averagg, 2Al.0 b 253.1 b 431A8A a** Fruit Firmness (Durometer Units) copper 57.3 55.0 58.7 57.0 dodine 56.8 5A.2 58.8 56.6 Difoiatan 56.6 5A.5 59.2 56.8 Average 56.9 b 5A.6 c 5889 a** Fruit Size (no. per 500 9) copper 113.2 130.A 105.0 116.2 a** dodine 100.5 128.6 103.A 110.8 ab Difoiatan 96.1 119.8 98.9 105.0 b Average 103.3 b 126.3 a** 102.A b Fruit Color (Absorbance)l copper 1.02 c 1.86’a** 1.01 c 1.30 a** dodine 0.82 de 1.63 b 0.9A cde 1.13 b Difoiatan 0.97 cd 1.56 b 0.78 e 1.10 b Average 0.9A b 1.68 a** 0.91 b ___, Fruit Solggle Solids (Z) copper 15.6 15.2 IAII 15.0 a** dodine 13.0 13.A 12.5 13.0 b Difoiatan l3.A 13.2 12.3 13.0 b Averag§_ 1A.O a** 13.9 a 13.0 b ** Average values followed by different letters, differ significantly at the 12 level. * Average values followed by different letters, differ significantly 1 at the 52 level. U.S.D.A. #1 Minimum color for red sour cherry = 0.325 absorbance at 515 nm. 23 Fruit soluble solids were significantly higher in the copper spray program. Fruit solids were significantly lower in 1972 than 1970 or 1971. Influence of Nittggen Level in Orchards #2 and #3 - 1970-1972. Table 3 shows pre-harvest fruit data for the two nitrogen levels in Orchards #2 and #3 from 1970 to 1972. Nitrogen levels had no effect on fruit firmness, size, color, or soluble solids content. No variant reaction to nitrogen applica- tions occurred in any year for any of the measurements. The high nitrogen application rate significantly increased the leaf N content. The reduced nitrogen content of leaves in 1972 was due to Orchard #2 not receiving any nitrogen at the ”low" level the previous two years. Fruit removal force was increased due to the high rate of nitro- gen applied, by a slight 6.2 grams over the three-year-period. Years and nitrogen application rates had no inconsistent (interactive) effects. Influence of Fungjgjde Chemicals in Orchard #1 - 1970-1972. (Low nitrogen level plots; averaged across tree age Blots). Table A shows the pre-harvest fruit measurement data averaged for tree age plots for 1970-1972, in Orchard #1. Low nitrogen level plots are compared, as differential levels were not incorporated in the 1970 tests. Table 3. 2A Influence of applied nitrogen on leaf nitrogen and pre- harvest sour cherry quality factors - 1970 to 1972. Orchards #2 and #3 - Year Nitrogen Level 1970 1971 1972 Average Leaf Nitrogen (Z); Low 2.17 2.52 2.23 2.A1 b High 2.60 2.6A 2.32 2.52 a** Average 2.53 a 2.58 a** 2.28 b Ffuit Removal Force (grams) Low 236.7 250.1 312.A 266.A 6 High 2A5.3 256.1 316.5 272.6 3* Average 2A1.0 b 253.1 b 31A.A a** Fruit Firmness (Durometer Units) Low 56.9 5A.2 59.0 56.7 High 56.9 5A.9 58.7 56.9 Average 56.9 b 5A.6 c 58.9 a** Fruit Size (no. per 500 9) Low 100.A 125.1 103.2 109.6 High 106.1 127.A 101.7 111.7 Average 103.3 b 126.3 a** 102.A b Fruit Color (Absorbance)I Low 0.98 1.71 ‘ 0.92 .20 High 0.39 1.65 0.90 .15 Average 0.9A b 1.68 a** 0.91 b Fruit Soluble Solids (2) Low 1A.1 1A.O 13.2 13.8 High 13.9 13.3 12.7 13.5 Average 1A.O a** 13.9 a 13.0 b ** Average values followed by different letters, differ significantly at the 12 level. * Average values followed by different letters, differ significantly 1 at the 5% level. U.S.D.A. Minimum color for red sour cherry = 0.325 absorbance at 515 nm. 25 Table A. Influence of copper and dodine fungicides on leaf nitrogen and pre-harvest sour cherry quality factors - Orchard #1 - 1970 to 1972. (Low nitrogen plots and two tree ages). Year Fungicide 1970 1971 1972 Average Leaf Nitrchen (2) copper ZfAA 2.32 2.567 2.AA dodine 2.59 2.52 2.51 2.5A Averageg, 2.52 2.A2 2.53 Fruit Removal Force (grams) copper 218.A 23AI8 316.6 256.6 dodine 223.5 222.2 3A5.0 263.6 AVGFBSE. 220.9 b 228.5 6 330.8 a** Fruit Firmness (Durometer UnitsE copper 60.1 a** 55.5 c 5 . ab 58.1 dodine 353.4 ab 57.4 b J58.6 ab 58.2 Averageg, 59.3 a** 56.A b 58.6 ab Fruit Si§e_(no. per 500 copper 133.2 abc 127.1 c 152.2 ab 137.5 dodine 131.7gg bc 15A.8 a* 1A3.9 abc 1A3.5 Average 132.5 b 1A0.9 ab 1A8:O a* _:Fruit Color (Absorbance)I copper 1.17 2.287 1.03 1.A9 dodine 0.90 2.21; 1.16 1.A2 Average 1.03 b 2.25 a** 1.10 b Fruit Soluble Solids (2) copper l6.A 16.2 16.8;—' 16.5 a* dodine 1A:3 13.9 16.27 1A.8 b Average 15.A’ ab 15.0 b 16.5 a** ** Average values followed by different letters differ significantly at the 12 level. * Average values followed by different letters differ significantly 1 at the 52 level. U.S.D.A. #1 Minimum color for red sour cherry = 0.325 absorbance at 515 nm. 26 Fruit removal force, fruit firmness, fruit size, and fruit color were not significantly affected over the three year period by the fungi- cides applied. Copper treated fruit were significantly higher in soluble solids. Yearly variation resulted in the following responses: 1) No significant difference in leaf nitrogen content was found between the three years. 2) Fruit removal force was greater in 1972 than 1970 or 1971. 3) Fruit firmness was greater in 1970 than in 1971, while the fruit in 1972 were intermediate in firmness. A) Fruit size progressively decreased from 1970 to 1972 with a significant size difference between 1970 and 1972. 5) Fruit color was greater in 1971 than in the other two years. 6) Fruit soluble solids was highest in 1972, intermediate in 1970, and lowest in 1971. Fungicide interactive effects with each year, show copper treated fruit were significantly softer in 1971 than 1970 or 1972. They were also softer than the dodine treated fruit in 1971. Copper treated fruit were significantly larger in 1971 than dodine treated fruit. Conversely, copper treated fruit were smaller in 1972 than 1971. Dodine treated fruit were smaller in 1971 than in 1970. However, neither fungicide had an effect on fruit size or firmness over the three year period. There were no other significant interactions. 27 Influence of Tree Age in Orchard #1 - 1970-1972. (Low nitrggen level plots; averaged over cgpper and dodine treatments). Table 5 shows pre-harvest measurements averaged for the c0pper- dodine fungicide treatments in Orchard #1 for 1970-1972. Low nitrogen level plots are compared, as differential levels were not incorporated in the 1970 tests. The difference in age of the producing blocks of trees in Orchard #1, had no interactive or main effects on percent of nitrogen in leaves, fruit removal force, fruit firmness, or fruit color from 1970 thru 1972. The younger trees produced fruit with significantly higher soluble solids content than the older trees, with no inconsistency in any year. As noted in Table A, fruit size progressively decreased each year. This was evidently due to the significant decrease in fruit size from the older trees. However, the younger aged trees produced consistently smaller fruit over the three-year period. There were no interactive responses between fungicide compounds and tree age plots from 1970 thru 1972. Influence of Nitrogen Levels in Orchard #1 - 1971-1972. (Averaged across fuggjcide and tree age Blots). Table 6 presents pre-harvest fruit data averaged for copper- dodine and tree-age plots, from Orchard #1 for 1971 and 1972. The higher rate of nitrogen application significantly increased the leaf nitrogen content. This higher rate decreased the fruit removal force, fruit size, fruit color, and fruit soluble solids over the two year period. There was no effect of increased nitrogen supply on the fruit firmness. 28 Table 5. Influence of two orchard ages on leaf nitrogen and pre- harvest sour cherry quality factors - Orchard #1 - 1970 to 1972. (Low nitrogen plots). Year Tree Age 1970 1971 1972 Average Leaf Nitlggen (2) Young 2.56 2.37 2.A1 2.A5 01d 2.A7 2.A7 2.65 2.53 Average 2.52 2.A2 2.53 Fruit Removal Force (grams) Young 220.877 211.7 333.67 255.3 01d 221.1 2A5.A 328.0 264.8 Average 220.9 b 228.5 b 330.8 a** Fruit Firmness (Durometer Units) Young 59.5 56.6 58.5 58.2 01d 59.0 56.3 58.8 58.0 Average 59.3 a** 56.A b 58.7 ab Fruit Size (no. per 500g% Young 1A5.5 abc 152.67 ab 13 .2 abc 1A5.5 a* 01d 119.A c 129.2 bc 157.8 a** 135.5 b Average 132.5 b 1AO.9 ab 1A8IO a* Fruit Color (Absorbance)l Young 1.05 2.38 1.21 1.55 01d 1.02 2.12 0.98 1.37 Average 1.03 b 2.25 a** 1.10 b Fruit Soluble Solids (2) Young 15:A 15.7 18.3 16.5 a** Old 15.3 1A.A 1A.7 1A.8 b Average_ 15.A ab 15.0 b 16.5 a** ** Average values followed by different letters differ significantly at the 1% level. * Average values followed by different letters differ significantly 1 at the 5% level. U.S.D.A. #1 Minimum color for red sour cherry = 0.325 absorbance at 515 nm. 29 Table 6. Influence of applied nitrogen on leaf nitrogen and pre-harvest sour cherry quality factors - Orchard #1 - 1971 to 1972. Year Nitrogen Level 1971 1972 Average Leaf Nitrogen (2) Low 2.A2 2.53 2.A8 b High, 2.51 2.72 2.62 a** Average 2.A7 b 2.63 a* Fruit Removal Force (grams) Low 228.5 330.8 279.7 a** High 204.3 303.2 253.8 b Average 2162A b 317.0 a** Fruit Firmness (Durometeg Units) Low 56.A 258.7 57.6 High 56.2 58.5 57.A Average 56.3 b 458:6 a* Fruit Size (no. per 500 g) LOW 1A0.9 1A8.0 1AA.5 b High 1A8.3 158.6 153.5 8* Average; 1AA.6 b 153.3 a** Fruit Color (Absorbance)I Low 2.25 1.10 1.68 a** High 2.0A 0.9A 1.A9 b Average 2.15 a** 1.02 b Fruit Soluble Solids (2) Low 15.0 16.5 15.8 a** High 1A.3 1A.2 1A.6 b Average 1A87 b 15.7 a* ** Average values followed by different letters differ significantly at the 1% level. * Average values followed by different letters differ l significantly at the 52 level. U.S.D.A. #1 Minimum color for red sour cherry = 0.325 absorbance at 515 nm. 3O Yearly variations were similar to those from 1970-1972 on the low nitrogen plots (Tables A 5 AA). Values for percent leaf nitrogen, fruit removal force, fruit firmness and soluble solids were signifi- cantly greater in 1972 than 1971. Fruit size was significantly smaller and contained significantly less color in 1972 than 1971. There were no interactive effects of nitrogen levels with either year, or with either tree age group. 11. FRUIT QUALITY FACTORS 0F CANNED CHERRY PIE-MIX FILLING AND FROZEN CHERRY PIES FOR 1971. The Difoiatan fungicide treatment was inadvertantly lost during harvesting operations at Orchard #2 in 1971, and does not appear in the processed product results. Influence of Orchard Location and Fungicide. Table 7 presents the data from tests in 1971 on the two processed sour cherry products for Orchards #1, #2 and #3, with copper and dodine fungicides averaged for nitrogen plots. The drained weight and integrity of fruit in the two processed products were not affected by the fungicide or the variability between orchard sites. The drained weight of the 5+1 pitted frozen sour cherries was also not affected. Fruit size (number-per-ounce) was not affected by fungicide treatments. Average fruit size varied for each orchard. The smallest fruit (greatest number-per-ounce) were from Orchard #1, and the largest from Orchard #3. The percent of defective fruit, i.e., “blemished cherries” (35), was very high for fruit from Orchards #2 and #3. However, only the differences for the canned pie filling were statistically signifi- cant between Orchard #1 and Orchards #2 and #3. Average values for the location and fungicide treatments were 27.0% and 31.2% blemished fruit in the canned fruit filling and frozen pies, respectively. Fungicides did not influence the percentage of defective fruit found. 31 32 Table 7. Influence of orchard location with copper and dodine fungicides on two sour cherry products - Orchards #1, #2 and #3 - 1971. Chergy Pie-Mix Fillingg_ Frozen Cherry Pies Fungjgide Fungicide Orchard cogger dodine Average ggpper dodine Average Fruit Drained Weight (oz) 1 7.73 8.00 7.87 10.587 10.13 10.35 2 8.09 7.52 7.80 10.80 10.63 10.71 3 8.4a 7.67 8.05 11.70 11:2? 11.53 Average 48109 7:73 11.03 10.70 Fruit Size (90. per oz) 1 16:0 16.1 16.1 a* l3.A 13.7 3.6 a** 2 12.9 13.6 13.3 b 11.3 11.A 11.3 b 33 11.5 12.0 __ 11.7 b ,9.9 39.5 9.7 c Average 13.5 13.9 11.5 11.5 Defective Fruit (2) 1 11.1 1A.] 12.6 b 13.6 15:67 1A.6 2 31.A 31.5 31.5 a 36.5 A2.A 39.5 3 3A.3 39.5 36.9 a** 38,1 A1.1 39.6 Average 25.6 28.A 29.A 33,0 3r Color Brightness (L Value) 2:2 1 19.78' 19.3A 19.567 b 18.95 18.50 18.73 2 20.31 20.A1 20.36 ab 19.15 19.85 19.50 3 21.28 20.89 21.08 a** 18.68 19.65 19.16 Average 20.E57‘ 20.21 " 18.93 19.33 Color Redness (L /Lb) 1 2.33 b 2.53 a* 2.A3 a§* 2.16 2.25 .21 2 2.2A bc 2.23 bc 2.23 b 2.17 2.16 2.16 43 2.16 c 2.18 c 2.17 b 2.08 2.01 .OA Average 2.2A b 2.32 a* 7’ 2.1A 2.1A Fruit Integrity (2) .3 1 95.3 93.5 93.0 9123 93.3 92.3;‘ 2 9A.5 97.5 96. 92.8 90.0 91.A 3 9§,0 97.3 97.6 87.5 92.5 91.0 Aveaage 95.9 96.1 90.5 91.9 Fruit Draineg:Wt - 3O lb.fgan (1b.) 1 20.72 20.30 20.51 2 21.08 21.32 21.20 3 22.A8 21.79 22.13 Average 21:53. 21:13 7' ** Average values followed by different letters differ significantly at the 12 level. * Average values followed by different letters differ significantly at the 5% level. 33 Color intensity of the canned filling was affected by the orchard source of the fruit. Orchard #3 had the least intense color (largest value) and Orchard #1 had the highest color intensity (Tables 1 and A1). Orchard #2 was intermediate and not statistically different from either of the others. The frozen pie fruit were not so affected. Fungicide sprays did not have any effect upon the color brightness of the finished products. The Hunter Color redness values (larger number indicates more red color) for the frozen pie fruit did not differ significantly for either location or fungicide variables. A trend toward decreased red color existed in the frozen pie for the fruit from each production area. This became significant for the canned pie filling. Orchard #1 produced fruit with a greater identifiable red color than Orchards #2 or #3. The average color redness of the canned cherry filling was significantly greater for dodine than for the c0pper fungicide. This resulted primarily from a significantly higher amount of color in fruit from the Orchard #l-dodine treatment. Influence of Nitrogen Applications with Cgpper and Dodine Fungicides - Orchards #1, #2 and #3 - 1971. Table 8 presents fruit quality data compiled from the processed cherry products for Orchards #1, #2 and #3 receiving low and high nitrogen applications with copper and dodine fungicide treatments in 1971. Processed fruit drained weight, color brightness and redness, integrity, and drained weight of the 5+1 pitted frozen sour cherries, were not affected by the nitrogen level treatments. 3A Table 8. Influence of nitrogen applications with copper and dodine fungicides on fruit quality factors of two sour cherry products - Orchards #1, #2, and #3 - 1971. m Cherry,Pie-Mlx Filling: Frozen Cherry Pies Fungicide Fungicide Ni e 0 er godine Average copper dodine Average Fruit Drained Weight (oz) Low 8.26 7.92 8.09 10.96 10.77 10.87 fllgh 37.92 7.59 7.73 11.09 10.6A 10.87 Average 8.09 7.73 11.03 10.70 Fruit Size (no.,per oz) Low l3.A 13.3 13.A 11.2 11.3 11.2 b High 13.6 1A.5 1A.1 11.9 11.8 11.9 a** Average 13.5 13.9 11.5 1155_ Defective Fruit (2) Low 26.8 b 33.A a* 30.1 a** 29.7 3A.2 31.9 High_ 2A.A b 23.A b 23.9 b 29,1 31.9 30.5 Average ,25.6 28.A 29.A 33.0 Color Brightness {5 Value) Low 20.32 20.2h 20.28 18.83 18.97 18.90 High 2;;0259 20.18 20.39 19.03 19.70 19.36 Average ago.h5 20.21 18.93 19.33 Color Redness (La/Lb) Low 2.25 2.33 2.29 2.1A 2.13 2.18 High 2.23, 2.30 2.26 2.13_ 2.1A 2.1A Average 2.2a b 2.32 a* _g.1h 2.15 Fruit Integritx(%) Low 94.2 95.7 90.9 *88.8 92.2 90.5 .ulgh .91.] _96.5 97.1 92.2 91.7 91.9 Average 95.9 96.1 90.5 91. Fruit Drained Wt - 30 1b. can (1b.) Low 21.23 21.38 21.30 High 21.63 g0.89. 21.26 Axerage 21.53 ,a,21.13 ** Average values followed by different letters differ significantly at the 12 level. * Average values followed by different letters differ significantly at the 5% level. 35 Fruit size was affected by different levels of nitrogen applied In the orchard. The higher nitrogen rate slightly decreased fruit size in both products, but was significant only for the frozen pie fruit. The percent of defective fruit in both products was lower at the high nitrogen level, but was significant only for the canned filling. The greatest percentage of blemished fruit in the canned filling occurred with the dodine-low nitrogen treatment. Influence of 00pper, Dodine and Difoiatan - Orchard #3 ' [271. Table 9 shows data for the processed cherry products from the three fungicide treatments at Orchard #3 in 1971. Copper, dodine and Difoiatan applied in Orchard #3 produced no significant differences in fruit quality of either cherry product or in drained weight of frozen pitted fruit. Influence of Tree Age - Orchard #1 - 1971. Table 10 contains data for the two cherry products showing the effects of differences in tree age for the fruit from Orchard #1 in 1971. The younger trees produced significantly greater fruit drained weight in the pie-mix filling but not in the frozen pie. These same fruit were significantly smaller in size, had less defects, and were darker in color for both products. The redness of these fruit was significantly higher only for the pie-mix cherries. Fruit wholeness of both products and fruit drained weight of the 5+1 pitted frozen cherries were not different for the two tree-age groups. Influence of copper, dodine and Difoiatan fungicides on fruit quality factors of two sour cherry products - Orchard #3 - Frozen Cherry Pies Fungicide copper dodine Difoiatan 11.70 11.36 10.75 9.9 9.5 9.0 38.1 Al.l 38.8 18.68 19.65 20.3A 2.08 2.01 1.90 87.5 92.5 86.3 Table 9. 1971. Cherry Pie-Mix Filling Fungicide Factors copper dodine Difoiatan Fruit Drained 8.AA 7.67 8.22 Weight (oz) Fruit Size 11.5 12.0 11.2 (no. per oz) Defective Fruit 3A.3 39.5 36.1 (33) Color Brightness 21.28 20.89 21.10 (L Value) Color Redness 2.16 2.18 2.19 (La/Lb) Fruit Integrity 98.0 97.3 93.3 (2) Fruit Drained 22.A8 21.79 21.AA Weight 30 lb. can (1b.) 37 Table 10. Influence of tree age on fruit quality factors of two sour cherry products - Orchard #1 - 1971. Cherry Pie-Mix Filling Frozen Cherry Pies Tree Age Tree Age Factors Young Old Fruit Drained 7.87 a* 7.3A b Weight (02) Fruit Size 16.1 a** 13.3 b (no. per 02) Defective Fruit 12.6 b 18.9 a* (%1 Color Brightness 19.56 b 20.87 a* (L Value) Color Redness 2.A3 a** 2.36 b (La/Lb) Fruit Integrity 9A.A 92.0 (2) Young 01d 10.35 10-70 13.6 a** 11.0 b 1A.6 b 19.A a** 18.73 b 20.08 a* 2.21 2.16 92.3 87.5 Fruit Drained 20.5 21.0 Weight 30 lb. can (1b.) ** Average values followed by different letters, differ signifi- cantly at the 1% level. * Average values followed by different letters, differ signifi- cantly at the 5% level. III. RAW AND PITTED SOUR CHERRY GRADE RESULTS - 1971 Raw Product Grade Table 11 shows the average grade (2) and defect categories for the raw product as determined by the Michigan State Department of Agriculture Inspection Service (26). Each treatment plot was inspected at the time of processing. The variation between treatment values was not significant except for the percentage of fruit under minimum color, which was higher for the younger trees. Most of the raw fruit grade reduction was due to wind whip- limb rubbed fruit and attached stems. The grade percentage decreased progressively from Orchards #1 thru #3, due to increases in these two categories. Pitted Product Grade (U.S.D.A. Score) and Percent Packout - 1971. Table 12 shows data compiled from the U.S.D.A. Score Sheets for Frozen Red Tart Pitted Cherries (35) determined by the U.S.D.A. Inspec- tion Service at each processing station. The percent packout equals the pounds of pitted fruit frozen for each treatment divided by the pounds of raw fruit entering the processing line. The ”freedom from pits” score between orchards was the only grade factor to vary significantly. Processed fruit from Orchard #2 scored lower (more pits) than those from Orchards #1 or #3. Grade factor values for all other treatments were not statistically different. Under the present U.S.D.A. scoring system, the ”limiting rule” restricts the 38 39 Table 11. The influence of orchards, fungicides, nitro en levels and tree age on the raw product inspection grade - 1971. Average Percentage Values Treatment Grade Wind Whip- Attached Under U.S. #l Decay Factors Limb Rub Stems Minimum Color Orchards 1 89.8 6.8 3.2 0.13 0.00 2 86.8 10.0 3.8 0.05 0.35 3 81.1 1A.0 A.8 0 00 0.03 Fungicide copper 85.2 11.6 3.0 0.03 0.20 dodine 86.2 8.8 A.8 0.08 0.05 Nitrogen Level Low 86.5 10.0 3.2 0.02 0.20 High 8A.7 10.5 A.6 0.10 0.05 Tree Age Young 89.7 6.8 3.3 0.13 a** 0.00 01d 91.8 A.3 3.8 0.03 b 0.00 Determined by the Michigan State Department of Agriculture Inspection Service at each processing plant. **Average values followed by different letters differ significantly at 1% level. AO Table 12. The influence of orchards, fungicides, nitrogen levels and tree age on the pitted product U.S.D.A. Score1 and packout percentage - 1971. Average Score Points Color Freedom Freedom Character Total Average (30)2 From Pits From Defects (30)2 Score Percent (20)2 (20)2 (100) Packout3 Orchard 1 28.6 18.8 a 18.9 28.1 9A.O 7A.1 2 28.5 17.0 b 16.5 28.1 90.1 78.3 3 28.5 19.0 3* 17.0 26.8 91.3 78.2 Fungicide copper 28.A 18.2 18.0 27.6 91.9 78.3 dodine 28.7 18.3 17.0 27.7 91.7 75.5 Nitrogen Level Low 28.8 18.7 17.7 27.6 92.7 78.2 High 28.3 17.8 17.2 27.8 90.9 75.6 Tree Age Young 28.6 18.8 18.9 28.1 9A.O 7A.l Old 28.A 17.0 18.6 28.A 92.A 81.7 Grades 8 Score points A 27-30 18-20 18-20 27-3OA c 2A-26“ 16-17“ 16-17“ 2A-26 SStd. 0-23“ 0-15“ 0-15“ 0-2u“ WN I. Average values followed by different letters differ significantly at the 5% level. Grade factors taken from the U.S.D.A. Score Sheet for Frozen Red Tart Pitted Cherries, determined for each treatment lot at each processing location, by the U.S.D.A. Inspection Service. Total score points allocated to the factor. Percent Packout = Pounds of pitted fruit X 100 Pounds of raw fruit U.S.D.A. Limiting Rule. Al final letter grade of a product to that of the lowest letter grade for each score factor - color, freedom from pits, freedom from defects, and character (35). The following treatments were graded “C”: Treatment Grade Reason Score Orchard #2 C Pits and Defects <18 Orchard #3 C Defects <18 dodine C Defects <18 Low Nitrogen C Defects <18 High Nitrogen C Pits and Defects <18 Old Trees C Pits <18 The packout percentage was not statistically significant for any of the treatments. DISCUSSION Orchards for this experiment were chosen to be representative of commercially producing units in three sour cherry production areas of Western Michigan. Each orchard contained the variable nature imposed on all production units because of differences in soil type, weather patterns, tree vigor, age, pruning and spacing. Many of the trees in each orchard had developed cankered main scaffold limbs and damaged central crotch junctions as a result of mechanical harvesting equipment. Orchards were selected near commercial processing facilities through which individual treatment lots could pass without losing their identities. Large spraying and harvesting equipment and commercial processing and re-manufacturing facilities were used. Fruit Removal Force (FRF) Fruit removal force values were below the 367 grams recommended by Cain (5). FRF was highest for Orchards #1 and #2 in 1972, probably because of retarded maturity, although soluble solids and fruit color were considerably above the levels in Orchard #3. The effects of the fungicides and nitrogen levels were not consistent between orchards and varied with the environment in each area and season. Fruit removal force might be a better indicator of fruit maturity than either color 42 A3 or soluble solids, since it would reflect the ease of mechanical har- vesting and the potential for fruit damage in attempting to detach a high percentage of the fruit. Fruit Firmness Fruit firmness was not affected by the fungicide, nitrogen level, or age of trees over the three-year-period in c00perator orchards. In 1971, copper Sprayed fruit were softest in Orchard #1 (Table A). In Orchard #3 (Table A3), c0pper treated fruit were firmer. This could be the result of reduced sample size since no fruit firmness difference between copper and dodine was apparent in the average for the three orchards in 1971 (Table A2). Fruit Size The number of fruit averaged between 100 and 153 per 500 grams in the three orchards (Table 1). They were slightly smaller at the high rate of N in Orchard #1 (Table 6), but not in Orchard #2 or #3 (Table 3). Smaller fruit at high nitrogen levels were found by Crocker (6). Copper treated fruit were smaller than dodine treated fruit in Orchard #1 in 1971, but not consistently smaller for the three year average (Table A). In Orchards #2 and #3, copper treated fruit were smaller than Difoiatan treated but not dodine treated fruit (Table 2). Fruit were substantially smaller from Orchard #1, irrespective of the treatments Imposed. Low vigor, extensive mechanical shaker injury and reduced leaf surface area were observed and may explain the smaller fruit. AA Fruit Color Raw fruit color was increased with the c0pper treatments in Orchards #2 and #3 (Table 2) but not in Orchard #1 (Table A). In 1971 (Tables A2 and A3), copper treatments produced the highest raw fruit color, but this did not affect the results in the processed product color measurements (Tables 7, 8 and 9). Higher rates of nitrogen reduced raw fruit color in Orchard #1 (Table 6) and in all three orchards in 1971 (Table AA). However, these differences did not carry over into the processed products (Tables 8 and 9). Lawver (17) reported decreased raw fruit color at maturity as the trees increased in age. There was no significant indications of this over the 3-year period (Table 5). in 1971, there were significant differences for the raw fruit (Table A5) which appeared in the two cherry products (Table 10). Fruit Soluble Solids Copper sprays have been reported to increase the soluble solids content of fruit (3, 10, 16, 17, 19, 25, 30, 32). Results presented agree with these reports (Tables 2, A, A2 and A3). In these tests, the high rate of nitrogen applied decreased the fruit soluble solids in Orchard #1 (Table 3), but not in Orchards #2 or #3 (Table 6), or for any orchard in 1971 (Table AA). A5 Fruit Drained Weight No variation in drained weight could be attributed to field treatments for the frozen pitted fruit prior to manufacture (Tables 7, 8, 9, 10). The cherry pie-mix drained weight was significantly higher for fruit from the young trees (Table 10). Fruit Defects There was no fungicide effect on the percentage of defective fruit, or fruit integrity of the processed products (Tables 7, 8 and 9). The higher rate of nitrogen applied in all orchards in 1971 (Table 8) decreased the defects percentage in the pie-mix, but failed to improve the frozen pie, or the integrity rating of either product. Less defec- tive fruit were found in both products for cherries from younger trees (Table 10). There was no effect on the integrity. Wind whip-limb rub (Table 11) varied 0.5 to 2.8 percent among all treatments, but varied a non-significant 7.2% between Orchards #1 and #3. The U.S.D.A. ”free- dom from defects” scores for the pitted product, would have been the sole factor in grading 5 of the treatments ”C“, if pits had not also been a problem (Table 12). Orchard and Season Orchard and year variability produced the greatest number of significant differences for the field measurements (Table 1). Year- to-year variability affected all harvest fruit measurements, except fruit soluble solids content. Often the year and Orchard measurement values were contradictory, indicating the inconsistency of results from one year to the next for any one orchard (Table 1). A6 Orchard #2 (Table 1) had the highest FRF and the lowest fruit firmness. Orchard #1 had the lowest FRF and the highest fruit firmness, color,solub1e solids, and the smallest fruit size. There were no leaf nitrogen differences among the orchards. In 1971 (Table A1), pre-harvest fruit in Orchard #3 had signifi- cantly higher FRF, lower firmness and color, and larger size than fruit from Orchard #1. Orchard #3 had a higher leaf nitrogen content than Orchard #1. The raw fruit grades (Table 11) were not statistically different, although Orchard #3 was 8.7% lower in grade than Orchard #1, due primarily to 7.2% more wind whip-limb rubbed fruit. Pitted fruit from Orchard #2 and #3 (Table 12) would have graded "C“ due to the ”Freedom from defects“ score being below 18.0. Fruit from Orchards #2 and #3 packed out about A.1% more pitted fruit than Orchard #1, indicating the processing facilities for Orchards #2 and #3 did not remove a sufficient number of cull fruit. High fruit color reported to mask the detection of defects (17) would not likely be the factor involved in preventing removal of sufficient cull fruit to produce a grade ”A” product. These defect differences appeared in the pitted products, however, a significant orchard difference was found only for the pie-mix cherries (Table 7). Orchard #3 produced larger fruit with greater drained weight, less color and more wholeness than Orchard #1. These effects were more readily identified in the pie-mix filling than in the frozen pie. Statistically, drained weight and integrity were non-significant. Greater fruit color, soluble solids, and fruit removal force for copper sprays were found (Table A2). The wind whip-limb rub portion of the raw fruit grade was 2.8% above the dodine grade, packed out A7 2.8% more pitted fruit than dodine treatments, and graded ”A” vs. ”C” for dodine treatments (Tables 11 and 12). The only significant dif- ference in the canned or frozen fruit desserts was improved red color (Table 7). Other differences would be likely to shift from one year to the next, much as the raw product measurements changed each season (Tables 2 and A). The nitrogen effects (Tables 3, 6 and AA) show small and inconsis- tent results on the pre-harvest fruit quality measurements, no effect on raw product grade (Table 11), and a 2.6% lower pitted fruit yield for the high rate of nitrogen applied (Table 12) with a U.S.D.A. grade ”C" due to defects. The dessert items indicated low N levels produced larger fruit with more defects present, but no other effects (Table 8). Younger aged trees produced smaller fruit with more soluble solids (Table 5), 2.5% more wind whip (Table 11), and graded “A” with a 7.6% lower packout rate of pitted fruit. Improved packout was not due to poor cull removal during the pitting operation. The pies and pie-mix fruit from these younger trees were higher in drained weight and color, and had fewer defects. SUMMARY Fuggjejde Effects Copper sprays in Orchards #2 and #3 produced fruit significantly smaller in size, and higher in fruit removal force (FRF), color and soluble solids. In Orchard #1, copper sprays increased fruit soluble solids content only. Difoiatan and dodine sprayed trees varied in fruit quality responses but never significantly exceeded the copper treatment responses. Copper responses in 1971, were significantly higher than dodine for fruit removal, color and soluble solids in all orchards. In one orchard fruit firmness was higher and smaller in size. Leaf nitrogen variation was not due to any fungicide treatments. Copper treated fruit in the cherry pie-mix, however, had less red color than the dodine treated fruit. The fungicides had no other effects on the two cherry products in 1971. Copper and dodine did not seem to influence either the raw or pitted fruit grades. Copper sprayed raw fruit had 2.8% more defects than dodine treated raw fruit, but in the pitted fruit, the dodine treatment scored U.S.D.A. grade ”C” because of defects present. Nitrogen Effects Leaf nitrogen content was increased by the high level of applied nitrogen. High nitrogen level increased the FRF slightly in Orchards #2 and #3, but decreased it at Orchard #1. Nitrogen levels in Orchards #2 and #3 had no other effects. In Orchard #1, the high level of N 43 A9 significantly decreased fruit size, color and souble solids. Fruit firmness was never affected by the nitrogen level applied. In 1971, FRF was not affected in the three orchards by the high N level applied, but fruit color was significantly decreased. While there was no significant differences in fruit size between nitrogen levels before harvest, the cherry pie fruit were smaller at the high N level, and the pie-mix fruit tended to support this. The high N level significantly reduced the fruit defect percentage in the pie-mix filling. The pre-harvest color differences noted between N levels, were not evident in the two processed cherry products. The two nitrogen levels had no effect on either raw or U.S.D.A. pitted product scores. Tree Age_Effects The effect of two different aged blocks of trees in Orchard #1, showed the younger trees produced smaller fruit in two of three years, with fruit consistently higher in soluble solids. In 1971, the younger trees were significantly lower in leaf nitrogen content, had a lower FRF, were smaller and had more color than fruit from the older tree block. Fruit in both processed products from the younger aged trees were smaller, had less defects, and more color. Fruit in the pie-mix filling from the young trees were also significantly higher in drained weight and red color. The percentage of raw fruit under minimum color grade were significantly greater from the younger trees. However, the age of trees producing fruit made no statistical difference on the 50 total raw grade or the total U.S.D.A. pitted product score. The pitted fruit from older trees graded "C" because of pits being present. Orchard and Season Effects Variation between orchards and between seasons produced a greater number of significant differences on pre-harvest measurements than did the treatments involved. Observed responses were usually not consistent between orchards in any one year, or between years in any one orchard. This inconsistency of effects makes it appear that there may be dif- ferences between fungicides in relation to quality of sour cherry fruit but these differences are likely to be realted to individual situations and not consistent for all sites and all years. In 1971, although many pre-harvest measurement differences were recognized as being difference for fungicide and nitrogen applications, these treatments had little effect on the finished products. The effects of seasons, orchard locations, and differences in tree ages had a greater effect on both the pre-harvest fruit measurements and the quality of the dessert items. LITERATURE CITED 10. LITERATURE CITED Bedford, C. L. and W. F. Robertson. 1953. Effect of spray materials on the quality of canned and frozen Montmorency cherries. Food Tech. 7(3):1A2-1AA. and . 1955. The effect of various factors on the drained weight of canned red cherries. Food Tech. 9(7lt321'323- and . 1962. Processed Montmorency cherries...a ten year summary. Mich. Agric. Expt. Sta. Quart. Bul. A5(2):33A-3AA. . 196A. Comparison of mechanically harvested and handpicked cherries after processing. 9A Ann. Report Mich. State Hort. Soc. pp. 87-90. Cain, John C. 1967. The relation of fruit retention force to the mechanical harvesting efficiency of Montmorency cherries. HortScience 2(2):53-55. Crocker, Thomas F. 1971. The effect of nitrogen, potassium and SADH on yield, quality and vegetative growth of sour cherry (Prunus cerasus L., var. Montmorency). Ph.D. thesis Mich. State Univ. Drake, Curtis W. 1966. My experiences in shaking and handling cherries at Cherry Hill Fruit Farm. 96 Ann. Report Mich. State Hort. Soc. pp. AO-A2. Floate, Ray. 196A. Problems confronting the cherry processor that should be of real concern to the grower. 9A Ann. Report Mich. State Hort. Soc. pp. 9A-97. Gardner, V. R. 1930. Maintaining the productivity of cherry trees. Mich. Agri . Expt. Sta. Special Bul. 195. Hartz, Robert E., and Kenneth Lawver. 1965. The effect of sprays on quality factors of canned red tart cherries. Food Tech. 19(1):A03-A05. 51 11. 12. 13. 1A. 15. 16. 17. 18. 19. 20. 21. 22. 52 Horsfall, James G. and A. L. Harrison. 1939. Effect of Bordeaux mixture and its various elements on transpiration. J. of Agric. Research 58(6):A23-AA3. Johnsen, Erik M. 19A9. Influence of spray materials on the structure of sour cherry leaves (Prunus cerasus L. var. Montmorency). M. S. Thesis Michigan State College, East Lansing, Mich. A882A. Kenworthy, A. L., and A. E. Mitchell. 1952. Soluble solids in Montmorency cherries at harvest as influenced by soil management practices. Proc. Amer. Soc. Hort. Sci. 60:91-96. . 195A. Effect of sods, mulches and fertilizers in a cherry orchard on production, soluble solids and on leaf and soil analysis. Tech. Bul. 2A3 Mich. State College Agric. Expt. Sta., East Lansing. . 1973. Leaf analysis as an aid in fertilizing orchards. In: Walsh and Beaton eds., Soil testing and plant analysis. Soil Sci. Soc. of Amer., 677 South Segoe Rd., Madison, Wisc. 53711. pp. 381-392. Langer, C. A., and Vernon J. Fisher. 19A9. Relation of wax emlusion and fungicidal sprays to size, color, and composition of fresh and processed Montmorency cherries. Proc. Amer. Soc. Hort. Sci. 5A:163-170. Lawver, Kenneth E., and Robert E. Hartz. March, 1965. Effect of sprays on quality factors of raw red tart cherries. Food Tech. 19(1):AOO-A03. Lepper, Henry A. ed., 19A5. Official and tentative methods of analysis of the Association of Official Agricultural Chemists. 6th ed. Association of Official Agricultural Chemists, Washington, D.C. 200AA. p. 27. Lewis, F. H., and A. B. Groves. April, 19A8. Control of cherry leaf spot in the Cumberland-Shenandoah Valley. Penn. Agric. Expt. Sta. Bul. A98. A0 p. Lyon, T. L., A. J. Heinicke, and B. D. Wilson. 1925. The relation of soil moisture and nitrates to the effects of sod on plum and cherry trees. Cornell Univ. Agric. Expt. Sta. memoir 91. pp. 21. Marshall, Roy E. 195A. Cherries and cherry products. Interstate Publishers, Inc., New York. 283 p. Martin, J. T. and E. Somers. 1957. Solubilization of copper by leaves and water-soluble acids from leaf wax. Nature 180(A590): 797-798- 23. 2A. 25. 26. 27. 28. 29- 30. 31. 32. 33. 53 McManus, George, Jr. 1972. Growing, harvesting and delivering quality cherries today. 102 Ann. Report Mich. State Hort. Soc. pp. llA-ll7. Rasmussen, E. J. 1937. A progress report on comparisons of high- calcium and high-magnesium limes in Bordeaux on sour cherry, and in zinc-lime and iron-lime mixture on peach. Proc. Amer. Soc. Hort. Sci. 3A:279-28A. . 1939. The effect of several spray materials on the size, color and percent solids, of the fruit of the Montmorency cherry. Proc. Amer. Soc. Hort. Sci. 37:367-370. Red sour cherries for processing, inspection instructions. September, 1960. United States Dept. of Agric., Agric. Marketing Service, Fruit and Veg. Div., Fresh Products Standarization and Inspection Branch, Washington, D.C. Rogers, A. J., Jr. 1927. Studies in orchard management, with special reference to cherry production. Special Bul. No. 166. Agjic. Expt. Sta. Mich. State College, East Lansing pp. A3. Smith, C. B., H. K. Fleming, and L. T. Kardos. 1961. Leaf com- position and performance of sour cherry trees as influenced by fertilizer and soil management. Bul. 683. Peno,_State Univ. College of Agric., Agric. Expt. Sta., Univ. Park, Penn. 16802. 13 p. Somers, E. and D. V. Richmond. 1957. Sorption of copper from burgundy mixture by leaves. Nature 180(A590):798-799. Taylor, 0. Clifton. 1953. The effects of organic fungicides, c0pper fungicides, and time of harvest on size, firmness and chemical composition of fruit of the sour cherry (Prunus cerasus L.). Ph.D. thesis Mich. State College, East Lansing, Mich. A8823. , and A. E. Mitchell. 1953. Relation of time of harvest to size, firmness and chemical composition of fruit of the sour cherry (Prunus cerasus). Proc. Amer. Soc. Hort. Sci. 62:267-271. and . 1956. Soluble solids, total solids, sugar content and weight of the fruit of the sour cherry (Prunus cerasus) as affected by pesticide chemicals and time of harvest. Proc. Amer. Soc. Hort. Sci. 68:12A-130. Thompson, W. W., A. E. Mitchell, A. L. Jones, G. R. Hooper, and A. J. Howitt. 1970. 1970 Fruit Spraying Calendar. Extension Bul. 15A Mich. State Univ. Coop. Extension Service, EaSt Lansing, Mich._A8823. 5A 3A. Unrath, C. R., A. L. Kenworthy, and C. L. Bedford. 1969. The effect of Alar, Succinic Acid 2,2-Dimethy1 Hydrazide, on fruit maturation, quality and vegetative growth of sour cherries, Prunus cerasus L., cv. "Montmorency”. J. Amer. Soc. Hort. Sci. 95(51:387-391. 35. United States Standards for grades of frozen red tart pitted cherries. Effective June 15, 196A. United States Dept. of Agric., Agric. Marketing Service, Fruit and Vegetable Div., Washington, D.C. 20250. APPENDIX 55 Table A1. Influence of orchard locations on sour cherry pre-harvest measurements - 1971. Orchard #1 #2 #3 Leaf Nitrogen 2.39 b 2.55 ab 2.63 a* (Z) Fruit Removal 202.A b 222.6 b 278.7 a** Force (grams) Fruit Firmness (Durometer Units) 56.7 a** 55.0 b 5A.3 b Fruit Size 156.1 a** 132.5 b 127.1 b (no./500 9) Fruit Color 2.29 a** 2.0A a 1.50 b (Absorbance) Fruit Soluble 1A.9 lA.7 1A.A Solids (%) ** Average values followed by different letters differ signi- ficantly at the 1% level. * Average values followed by different letters differ signi- ficantly at the 5% level. 56 Table A2. Influence of copper and dodine fungicides on sour cherry pre-harvest measurements - Orchards #1, #2 and #3 - 1971. Fungicide copper dodine Leaf Nitrogen 2.51 2.5A (2) Fruit Removal 2A1.8 a** 227.3 b Force (grams) Fruit Firmness 55.A 55.2 (Durometer Units) Fruit Size 137.2 1A0.0 (no. per 500 9) Fruit Color 2.03 a** 1.85 b (Absorbance) Fruit Soluble 15.5 a** 13.8 b Sol ids (z) ** Average values followed by different letters differ significantly at the 1% level. * Average values followed by different letters differ significantly at the 5% level. 57 Table A3. Influence of copper, dodine and Difoiatan on sour cherry per-harvest measurements - Orchard #3 - Fungicide copper dodine Difoiatan Leaf Nitrogen 2.53 2.61 2.6A (2) Fruit Removal 288.7 a** 268.6 261.9 b Force (grams) Fruit Firmness 5A.7 a* 53.6 5A.2 ab (Durometer Units) Fruit Size 135.2 a** 122.3 116.8 b (no. per 500 9) Fruit Color 1.75 a** 1.3A 1.5A ab (Absorbance) Fruit Soluble 15.0 a* l3.A l3.A b Solids (%) ** Average values followed by different letters differ signifi- cantly at the 1% level. * Average values followed by different letters differ signifi- cantly at the 5% level. 58 Table AA. Influence of nitrogen application on sour cherry pre-harvest measurements - Orchards #1, #2 and #3 - 1971. Nitrogen Level Low High Leaf Nitrogen 2.A7 b 2.57 a* (%) Fruit Removal 235.6 233.5 Force (grams) Fruit Firmness 55.A 55.2 (Durometer Units) Fruit Size 137.2 1A0.0 (no. per 500 9) Fruit Color 2.01 3* 1.88 b (Absorbance) Fruit Soluble 15.0 lA.3 Solids (%) ** Average values followed by different letters differ significantly at the 1% level. * Average values followed by different letters differ significantly at the 5% level. 59 Table A5. Influence of tree age on sour cherry pre-harvest measurements - Orchard #1 - 1971. Tree Age Young 01d Leaf Nitrogen 2.39 b 2.5A a* (%) Fruit Removal 202.A b 230.5 a** Force (grams) Fruit Firmness 56.7 56.0 (Durometer Units) Fruit Size 156.1 a** 133.1 b (no. per 500 9) Fruit Color 2.29 a* 2.00 b (Absorbance) Fruit Soluble 1A.9 1A.A Solids (%) ** Average values followed by different letters differ significantly at the 1% level. * Average values followed by different letters differ significantly at the 5% level. IIliilillgljllllflllllllllflliI I 5