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Supplemental calcium supplied foliariy as Ca glutarate, soil incorporated as gypsum, fertigated as CaNO3, in 3-way combination, or none at all, had no effect on fruit firmness, as measured by shear, reduced fruit decay by as much as 23%. over controls (1986-1988), and generally improved fruit Ca levels only in the combination treatment of 904 kg/ha. Fruit raw product quality (pulp pH, acidity, soluble solids concentration, and Hunter color values) were not consistently affected, although there were significant interactions between cvs Fern and Cardinal, harvest dates, holding time, and years. Supplemental Ca reduced fruit size, but tended to increase yield. In 1988, individual fruits were partitioned into upper/lower, dermal/interior, and upper/lower seeds (6 parts), Ca was the third most abundant mineral nutrient in receptacle tissue, but most abundant in seeds. Highest Ca levels were found (descendingly) in the seed, dermal, and interior pulp tissue, Ca was higher in the upper (stem) end. Differences in fruit Ca levels between cvs were found in the seeds and not the receptacle. No clear relationship was observed between fruit firmness, decay, and Ca level.

Fruit of `Cardinal' and `Fern' were harvested, acid washed, decapped, and frozen to -20° C on 6 May 88. Frozen fruits were subsequently divided into six parts. The upper and lower fruit halves were further separated into pulp, dermal, and seed components. Nutrients increased from the pulp to the seed with the exception of Al. K was most abundant in receptacle tissue (but not in seeds) followed by P, Ca, and Mg. K, Ca, Mg, and Cu were higher and Mn and Zn lower in pulp upper tissue than lower pulp tissue. K, Ca, Na, Zn, and A1 were higher in upper dermal tissue than in lower dermal tissue. Ca, Cu, and B were higher and Mg and Mn lower in upper octanes than in lower achenes. In descending order, Ca, P, Mg, and K were the most abundant seed nutrients. Supplementing strawberries with 904 Kg Ca/ha increased only the seed Ca levels. All levels of supplemental pre-harvest Ca were found to reduce postharvest decay. Although `Fern' was higher in seed Ca, with similar Ca levels in receptacle tissue, fruit decay was higher than in `Cardinal'. There appears to be no clear relationship between fruit decay and Ca distribution within the fruit.

The response of 4 erect blackberry cultivars to 2 levels of soil moisture and 2 hedge pruning heights was evaluated. Supplemental irrigation increased yield on all cultivars, but was most effective for the highest-yielding cultivar, ‘Cherokee,’ during the first harvest season (6.03 T/ha for irrigated plots compared to 4.22 T/ha for nonirrigated plots). Increased lateral branching and yield, with no effect on fruit quality, resulted when the new primocanes were pruned mechanically to a height of 90 cm compared to 120 cm. ‘Cherokee’ and ‘Comanche’ berries had superior color compared with that of other cultivars. Irrigation resulted in a slight reduction in percentage of soluble solids and pH.

Three cultivars of strawberries (Fragaria × ananassa Duch. cvs. Cardinal, A-5344, and Earlibelle) were harvested once-over by machine in 1975 and 1976 and separated into green and ripe fruit. Preserves and jam were manufactured from different combinations of sliced, ripe fruits, puree from ripe and from green fruit, then stored at 2°, 24° and 35°C for 0, 4 and 9 months. There were differences among cultivars and treatments in color attributes and sensory quality but both preserves and jams were highly acceptable from all cultivars and treatments. The greatest change in color and sensory quality was caused by storage at 35° for 4 and 9 months. Green fruit did not affect storage stability and development of browning. As much as half immature, green fruit can be used in the manufacture of preserves and jams without affecting quality in highly-colored cultivars.

Fruit samples of grape (Vitis labrusca L., cv. Concord) from 6 vineyard locations were collected at 7 to 10-day intervals beginning prior to veraison and continuing through development of 16% soluble solids for a period of 19 years. The 19-year average date for peak bloom in these vineyards was May 19, for 8% soluble solids development was July 27 (69 days from peak bloom), and for 16% soluble solids development was August 23 (96 days from peak bloom). Heat unit summations were more closely related to development of soluble solids than to changes in either titratable acidity or color. Using degree-day accumulations and effective heat unit summations did not prove to be methods superior to use of the number of calendar days for predicting grape maturation. Predictions from 8 to 16% soluble solids development were more accurate than predicting from peak bloom (when 50% of clusters showed bloom). Variations between years and between vineyard locations within a given year prevented accurate predictions from the 3 methods. Other deterrents observed in predicting development of soluble solids included the cultural variables of fruit load and soil moisture.

Under commercial conditions at harvest, mechanically harvested blackberries (Rubus sp.) had raw and processed quality comparable to hand-picked fruits regardless of berry temperature. However, during storage, berries machine-harvested at high temperature (36°C) deteriorated more rapidly than hand-picked berries at the same temperature. Storage of machine-harvested fruit in 20% and 40% CO2 at 20° for up to 48 hours maintained raw and processed quality. When mold counts were not excessive, the use of flavoring ingredients in the processed product resulted in acceptable products despite unacceptable raw product quality from some treatments. Use of high CO2 storage atmospheres with fruit held at 20° partially offset the need for refrigeration to reduce postharvest quality loss.

Two cultivars of strawberries originally harvested for fresh market were held under 5 postharvest storage treatments and then dipped in one of 4 chemical treatments. The berries were sliced or left whole, dipped, and then processed by freezing or thermal processing. The processed product from ‘Cardinal’ was superior to that from ‘Sunrise’ in this study, regardless of the holding or dip treatment. ‘Cardinal’ berries could be utilized for processing initially and after storage for 4 days at 4°C and after 2 days at 21°; however, ‘Sunrise’ was acceptable only initially and up to 4 days at 4°. Dipping berries for 1 min in a 0.5% calcium lactate solution or a 0.5% Ca lactate plus 1% citric acid solution improved berry firmness and character. The Ca dips were more effective in firming sliced berries than in firming whole berries. The Howard mold count of the berries became a major limiting factor for many of the postharvest storage treatments.

Retaining more fruiting nodes/vine increased yield, but reduced fruit quality in ‘Concord’ grape (Vitis labrusca L.). Geneva double curtain (GDC) training produced more fruit with better quality than a single wire cordon training system. Positioning the current season’s growth vertically toward the vineyard floor increased yields of vines pruned to short (3-node) spurs. Yield was increased by shoot positioning the season after performing the operation, however, fruit quality was improved during the season that vines were shoot positioned. Pruning vines to 6- or 9-node canes increased yield without a sacrifice of fruit quality as compared to 3-node spurs and reduced the yield increasing potential of shoot positioning. Use of longer canes, GDC training, and shoot positioning grapevines in Arkansas may allow less severe pruning than the currently recommended 30+10 pruning schedule to increase yield without a loss in fruit quality. Pruning weights were generally reduced by treatments which increased yield.

Fruits of ‘Cardinal’ and A-5344 strawberries (Fragaria X ananassa Duch.) were once-over harvested and sorted into 5 maturity categories: immature green, mature green, inception, firm ripe, and processing ripe. Purees of each maturity were characterized for their potential contribution to the quality of puree obtained from a once-over strawberry harvest. As the berry matured, weight, percent soluble solids, ascorbic acid, and water-soluble pectins increased. Total solids, acidity, total phenols, puree viscosity, cellulose, protopectin, peroxidase activity (PO), and polyphenol oxidase (PPO) activity decreased with increasing fruit maturity. Presence of chlorophyll, lack of anthocyanins, higher total phenols, and PO and PPO activity found in the green fruits could be potentially detrimental to puree quality. Higher puree viscosity which resulted from higher cellulose and protopectin levels and lower water-soluble pectins in the green berries would be beneficial to strawberry puree quality.

Yields on ‘Concord’ grape (Vitis labrusca L.) increased as pruning severity was decreased until the 6th and last year of this study, at which time the yields tended to equalize between the 30 + 10, 50 + 10, and 70 + 10 pruning treatments. By the last year, vines pruned to the 70 + 10 level produced fruit of unacceptable quality. When the 3-node spurs were shoot-positioned, their productivity was comparable to buds on the 6- and 9-node canes, indicating the need for exposure to sunlight. The length of the bearing unit has little or no effect on fruit quality attributes. In general, shoot positioning increased yield, node productivity, the percentage of soluble solids, and lowered vine size throughout the study. Geneva Double Curtain (GDC) trained vines produced more fruit than the bilateral cordon (BC) trained vines. Fruit from GDC trained vines had a reduced percentage of soluble solids in 2 of the last 3 years, and tended to have a low pH. The most productive vines producing fruit of acceptable quality for the 6-year mean were the GDC trained, 50 + 10 pruned to 6-node bearing units, and shoot positioned.

Purees were prepared from green (G, immature and mature green 1:1) and ripe (R, firm ripe and processing ripe 1:1) fruits of ‘Cardinal’ and A-5344 strawberries (Fragaria × ananassa Duch.). Blends of 25%R + 75%G, 50%R + 50%G, 75%R + 25%G, and 100% R were prepared before and after holding purees at 10, 30 and 50°C for 0, 12, 24 and 36 hours. The decrease in puree color caused by the addition of puree of green fruit to puree of ripe fruit was a dilution effect rather than a synergistic effect, since pures of green and ripe fruits combined after holding were equal in color to purees of comparable proportions of purees of G and R fruits combined before holding. Holding strawberry puree for up to 36 hours at 30° and 50°C increased discoloration and reduced total anthocyanins, pelargonidin-3-monoglucoside content, COM “a”, and visual color. Holding at 50° resulted in the greatest reductions in color.

Midsummer grapehoeing following spring application of diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] or simazine [2-chloro-4,6-bis(ethylamino)-s-triazine] plus paraquat (1,1’-dimethyl-4,4’-bipyridinium ion) adequately controlled weeds growing in grapes (Vitis labrusca L.). When grapehoeing was used to control grape root borer [(Vitacea polistiformis Harris) lower initial rates of preemergence herbicide could be used. An additional half-rate of herbicide was required after grapehoeing to maintain weed control through the fall. Plots not grapehoed were almost completely weed free following a glyphosate [N-(phosphonomethyl)glycine] treatment. Injury to grapes the following spring was associated with fall glyphosate applications where low hanging foliage, that had not been removed, intercepted the spray. Glyphosate was most effective and paraquat more effective than dinoseb (2-sec-buty1-4,6-dinitrophenol) plus diesel fuel for postemergence control of weeds in grapes. Preemergence herbicides, napropamide [2-(α-naphthoxy)-N,N-diethylpropionamide], norflurazon [4-chloro-5-(methylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone], oxadiazon [2-tert-buty1-4-(2,4-dichloro-5-isopropoxyphenyl)-∆2-l,3,4-oxadiazolin-5-one], oryzalin (3,5-dinitro-N4,N4-dipropylsulfanilamide), and oxyfluorfen [2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene], were effective as residual type treatments.

A study was designed to examine the effects of production systems (i.e., standard bed, wide bed, and black plastic bed), a high and low plant population, and 3 harvest dates on the machine-harvested yield and quality of 2 strawberry (Fragaria × ananassa Duch.) clones. ‘Cardinal’ produced higher yields than A-5344, but had poorer quality. The wide-bed production system produced higher yields than the other production systems and had no adverse effects on quality. ‘Cardinal’ had optimum yield when produced under a low plant population, while A-5344 had optimum yield under a high plant population. Fruit quality was maintained throughout the 5- to 7-day harvest season each year.

The development of a mechanical harvester for erect blackberries is traced from its inception to commercialization. The harvesting and production system tested in this study required productive, erect cultivars that are mechanically pruned to form continuous hedgerows. An acceptable processed product is obtained from the system.

Firm-fruited strawberries (Fragaria × ananassa Duch.) for processing can be mechanically harvested, properly handled and then held for up to 48 hours at 24°C for 7 days at 1.7° without excessive quality loss. High mold count and a reduction in other quality attributes occur after 96 hours at 24°. Ripe fruit held for 48 hours at 24° and then processed was acceptable to a sensory panel. The effects of overwrapping appeared to be limited to quality changes associated with dessication. Benomyl treatment had a suppressing effect on mold count and reduced loss of soluble solids.

Horseradish peroxidase (PO) and mushroom polyphenol oxidase (PPO) were added to strawberry purees from ‘Cardinal’ and Arkansas breeding-line 5344 to determine their influence on color during 48 hours at 30°C. Neither enzyme affected strawberry puree color or phenolic content. PO activity was reduced to near zero 24 hours after addition and PPO activity was undetectable 1 hour after addition to puree. Aeration did not affect anthocyanin and flavonoid concentrations, but increased discoloration and nonflavonoid concentration. Strawberry purees containing 50% immature plus 50% ripe fruits were poorer in color and had higher levels of flavonoids. As holding time at 30°C increased, puree color decreased.

Succinic acid-2,2-dimethylhydrazide (daminozide) applied at 1800 ppm to 10-year-old ‘Babygold-5’ and ‘Babygold-8’ peach trees (Prunus persica (L.) Batsch) at pit hardening advanced fruit maturity and increased tolerance of low soluble solids fruit by improving flesh color. Fruit softening, the disappearance of flesh chlorophyll, and reductions in puree viscosity were the primary benefits obtained from the application of daminozide. Daminozide advanced maturation generally, rather than concentrating the fruit into a more uniform maturity class. Flesh color and acidity were highly correlated with loss of fruit firmness of both control and daminozide-treated fruit, but daminozide treated fruit improved in flesh color more rapidly than control fruit as firmness decreased. Acidity remained consistently higher for treated fruit at all firmness levels. The mechanism by which daminozide advanced maturity did not appear to be active during postharvest holding of these clingstone cultivars. Further ripening as a result of postharvest storage of both treated and control fruit occurred at about the same rate during a 2, 4 or 6 day period at 18°C.

A study was conducted on 2 cultivars of mechanically harvested strawberries (Fragaria × ananassa Duch.) to determine the effects of chemical treatments and heat on stability of color in frozen fruit for jam. Treatment with NaHSO3, citric acid or SnCl2 improved color of the jam when compared to the control, as demonstrated by Color Difference Meter (CDM) values and sensory ratings. The CDM color functions were higher on jam made from frozen puree than from frozen whole fruit, yet panel scores were significantly higher on jam from whole fruit. The jam made from frozen puree browned more during storage than that made from whole fruit. There were significant differences in color between cultivars and storage temperatures, but differences among treatments were larger. Treatment with NaHSO3, citric acid or SnCl2 offer possibilities for stabilizing color in jam.

(2-Chloroethyl)phosphonic acid (ethephon) was sprayed on irrigated and non-irrigated erect (‘Cherokee’ and ‘Comanche’) blackberries (Rubus, subgenus Eubatus) before the first harvest and after the second harvest at 1000 and 1500 ppm. ‘Cherokee’ had higher and more concentrated yields and better color than ‘Comanche’. Dripirrigation increased yield and berry weight, but reduced both raw and processed fruit color. Ethephon applied before the first harvest or after the second harvest increased the amount of early fruit harvested. Ethephon reduced berry weight, percent soluble solids, titratable acidity, and increased the pH, and raw and processed product color.

Temperature of fruit of Vitis labrusca L. cv. Concord at harvest was the primary factor governing the rate of postharvest quality changes. Fruit harvested at mid-day at 32°C remained at that temperature inside a bulk pallet box for 72 hours, regardless of diurnal temperature fluctuations. Without addition of SO2, alcohol concentration steadily increased after 12 hours holding the mechanically-harvested grapes in a bulk pallet box and reached 3% after 72 hours. Loss of soluble solids began immediately after harvest and after 72 hours, 44% of the soluble solids present at the time of harvest had been lost. Addition of S02 at harvest or no later than 6 hours after harvest aided in slowing postharvest deterioration. The addition of 80 or 160 ppm SO2 to a bulk pallet box of grapes mechanically harvested at a temperature of 35° was as effective in retarding postharvest deterioration of the quality attributes determined in this study as was harvesting at 24°. Harvesting at a cool temperature (24°) and SO2 addition will allow for extended holding of the raw product with minimal alcohol production and raw product quality loss.

‘Carlos’ muscadine grapes (Vitis rotundifolia Michx.) were sorted into 5 density grades using 4 brine solutions of 8, 9, 10 and 11% NaCl. Soluble solids and berry weight increased, color improved, and acidity decreased with grape maturity and brine concentration. Panelist’s sensory preference increased with increasing density (maturity). Berries that floated and sank in 11% NaCl (density grades 4 and 5) had acceptable ratings for flavor, aroma, and color. Density separation was used to monitor the rates of maturation of the cultivars ‘Carlos’ and ‘Noble’. The technique was useful in characterizing the changes in berry population during the last month of ripening.

When vines of ‘Concord’ (Vitis labrusca, L.) trained to the Geneva Double Curtain were irrigated or pruned to 60+10 nodes/vine, yield was increased with some sacrifice in juice quality, as indicated by lower % soluble solids and poorer juice color. High quality juice was obtained from fruit from 60+10 irrigated vines, the highest yielding treatment, when harvest was delayed 10 to 14 days. Level of nitrogen fertilization did not affect yield, % soluble solids, or juice color. Irrigation was the only experimental variable affecting vine size. High yields from irrigated and 60+10 vines found in this study indicated that the fruiting potential of the ‘Concord’ grapevine in Arkansas has not been fully exploited.

A processing study was conducted on 2 cultivars, 3 extraction temperatures, 3 storage temperatures and 3 storage times to assess differences in quality of juice of muscadine grape (Vitis rotundifolia Michx.) The 2 cultivars responded differently to all other variables in color changes. ‘Carlos’, a bronze-skinned grape was higher in acidity and lower in pH and total phenols than ‘Noble’, a black-skinned cultivar. Higher extraction temperatures leached out more acids, total phenols, and color. Color and overall quality changes were rapid at 32°C storage, making the juice unacceptable at 7 months storage. Greater changes in quality occurred when juice was extracted at 60° than at 24° or 80°.

A 4-year study was conducted on ‘Niagara’ grapes (Vitis labrusca L.) to examine the effects of 3 pruning severities (based on nodes retained), 3 levels of nodes/bearing unit (3, 6, and 9), 2 training systems [Geneva Double Curtain (GDC) and Bilateral Cordon (BC)], and 2 canopy management treatments (shoots positioned and shoots not positioned) on yield and fruit quality. Leaving heavy fruit loads suppressed yields in the 4th and final year of this study as a result of reduced node fruitfulness. The 3 node spurs were not as productive as the 6 and 9 node canes. GDC training produced higher yields than BC training in the 3 high yielding years of the study while maintaining vine vigor. Shoot positioning was more beneficial in increasing yields on the BC training system than on the GDC training system, because of the crowded conditions of the canes on the BC system. The effects of these variables on fruit quality were small, but the heavy fruit loads did result in fruit with a reduced percentage of soluble solids and pH, increased acidity and light color (increased CDM ‘L’ values). Shoot positioning reduced fruit pH, slightly in-creased acidity, and produced darker color (decreased CDM ‘L’ values). Under Arkansas growing conditions, if harvest is delayed beyond 14% soluble solids, it is possible that unacceptable fruit pH and acidity levels will exist.

A completely mechanized system for production, harvesting and handling strawberries (Fragaria × anassa Duch.) for processing is described. Pre-harvest cultural factors, including bed preparation, plant population, harvest date and clonal evaluation and adaptability to mechanical harvesting, were studied for 4 years. ‘Cardinal’, ‘Earlibelle’, and Arkansas breeding line A-5344 were well suited for once-over mechanical harvesting under Arkansas conditions considering yield, quality, and organoleptic evaluation. Plant population densities in the matted row system used in this study generally had little effect on yield or quality, unless a clone was of low vigor and poor runner plant producer. As harvest date was delayed, quality and useable yield often decreased. However, a minimum of a 6 day harvest period for mechanical harvesting existed for the cultivars tested. The results of this study indicate that once-over mechanical harvesting of strawberries is feasible when the proper cultivar is grown on properly shaped beds with good cultural practices and adequate postharvest handling procedures.

Four of 7 strawberry (Fragaria X ananassa Duch.) clones tested did not benefit in total yield from 1 or 2 hand pickings prior to once-over machine harvest. Four of the clones could be hand picked once without a significant reduction in machine harvested yields. Two clones were low yielding regardless of the harvest method. ‘Sunrise’, a high once-over yielding clone, increased in total yield with hand harvesting but fruit were soft and poorly colored and lacked good field holding and in-plant handling capabilities. ‘Cardinal’ represented a clone with fruit quality and a ripening pattern suitable to a combination of hand and machine harvesting. Fruit remaining on the plants after 1 or 2 hand harvests had a higher percentage of ripe fruit in the once-over harvest than machine harvested fruit not preceded by a hand harvest. The composite once-over machine harvested fruit after 1 or 2 hand pickings showed the same or higher soluble solids, shear press firmness, puree viscosity and color intensity as hand harvested fruit. In clones with high quality fruit, the presence of immature fruit in the onceover harvest did not detract from puree color or flavor acceptability. Selection A-5344 possessed both yield and quality characteristics desired for a completely mechanized harvest for processing.

Mechanically harvested fruits of A-5344 and ‘Earlibelle’ strawberry (Fragaria × ananassa Duch.) were stored at 24°C for 72 and 120 hours in atmospheres containing acetaldehyde (Aa) with and without prior dipping in 0 to 1.5% acetaldehyde solutions. Aa atmospheres and a combination of atmospheres and dips were most effective in maintaining visual color, freedom from browning, and product acceptability of machine harvested strawberries for processing. Fruit stored in atmospheres containing Aa vapor increased in acidity by 72 hours.

Glyphosate (N-phosphonomethyl glycine) was applied to low-hanging foliage and basal shoots of ‘Concord’ grapevines (Vitis labrusca L.) at 2.2 and 4.4 kg/ha in August, September, and October 1979. All treatments were extremely injurious to grapevines. Injury was evident throughout the grapevine the following spring and during the full growing season. Growth on new shoots, visual ratings of growth reduction during the season, grape yield, and pruning weights indicate 50% or more reduction in growth as compared to the untreated check. The September treatment appeared more injurious than the August or October treatments.

A site was prepared with 2 distinctly different soil depths and a vineyard of ‘Concord’ grapes (Vitis labrusca L.) was established with in-row spacings of 1.52, 1.83, 2.13, 2.44, and 3.05 m. Wider in-row vine spacings resulted in increased vine yields on deeper soils to the point that yields per meter of cordon and per hectare were not reduced; but yield per meter of cordon and per hectare was reduced on the shallow soil when in row vine spacings exceeded 2.44 m. There were few effects on juice quality from either soil depths or in-row vine spacings.

Single and split applications of (2-chloroethyl)phosphonic acid (ethephon) at different concentrations to ‘Concord’ grapes(Vitis labrusca L.)did not influence maturation. When ethephon was applied 8 days prior to harvest, abscission was enhanced and postharvest alcohol accumulation was reduced when fruit was shaken from the vine and held at 30°C for up to 24 hours.

Succinic acid-2,2-dimethylhydrazide (daminozide) applied to ‘Raven’ blackberries at 4000 ppm and to ‘Raven’ and ‘Brazos’ at 2000 ppm between full bloom and first color development and at 2000 ppm in a multiple application applied at full bloom, 2 weeks, and 3 weeks after full bloom resulted in reduced berry size and yield with no beneficial effects on fruit quality. (2-Chloroethyl) phosphonic acid (ethephon) applied to the same cultivare at 1000 ppm 4 days prior to the first harvest increased the amount of fruit mechanically harvested on the first harvest. Ethephon treatment improved color but resulted in mechanically harvested fruit having lower soluble solids and acidity.