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Two field experiments were carried out in 2022 and 2023 within commercial watermelon fields in Stockton and Modesto, CA, USA. Two Trichoderma-containing products were applied to the grafted and nongrafted watermelon seedlings through tray soaking or field chemigation. All seedlings were mechanically transplanted into a split-split plot design with the Trichoderma product as the main factor and application method (tray soaking and chemigation) as the sub-plot. The sub-sub-factor included three interspecific hybrid squash rootstocks (Cucurbita maxima × Cucurbita moschata) 'Cobalt', 'Flexifort', and 'RS841' that were grafted with the commercial seedless watermelon scion 'Summer Breeze'. All treatments were replicated four times. Vine health was visually assessed three times, and canopy coverage was assessed for a total of six measurements for each year. Harvest was conducted three times in 2022 and twice in 2023 to analyze yield and quality differences among treatments. Aboveground and root samples from defective plants were taken amid the harvest and shipped to the University of California, Davis Fungal Pathology Diagnostics Research Laboratory for identification of soilborne fungal pathogens to confirm or rule out their involvement in vine declines initially attributed to nonpathogenic factors. The laboratory diagnosis indicated that Macrophomina was morphologically identified from the foot and root isolations of 67% of the submitted nongrafted, non-Trichoderma-biofungicide-treated plants in 2022. Further sequencing results confirmed the primary pathogen, Macrophomina phaseolina, from 50% of those submitted plant samples. In addition, putative Fusarium root and stem rot (Fusarium oxysporum f. sp. radices-cucurmerinum) and Falciforme crown rot and decline (Fusarium noneumartii) from runners and roots of nongrafted, noninoculated plants in the 2022 experiment were also reported. However, no significant soilborne fungal pathogens were found in the 2023 experiment. In both trials, the effects of Trichoderma-containing biofungicides and their application methods on preventing vine decline, maintaining canopy coverage, and enhancing fruit yield and quality were not as remarkable as grafting. The average grafting effect contributed to 83% and 53% decrease of vine decline compared with the nongrafted plants in 2022 and 2023. Overall, grafted plants yielded 47.6% and 32.4% more than the nongrafted counterpart in 2022 and 2023, respectively. In addition, grafting exerted predominant influence on fruit firmness and rind thickness. The study results indicated that grafting onto multipathogen resistance watermelon rootstocks serves as an effective production tool to maintain fruit yield, quality, and plant health under both pathogenic and disease-free conditions. Further work is still needed to continue evaluating best practical application protocols of Trichoderma-based biofungicides and other biopesticides to enhance product effectiveness and end users' confidence in reducing soilborne diseases and reliance on conventional fumigants. [ABSTRACT FROM AUTHOR]

Understanding consumers' preferences for fruit quality attributes is key to informing breeding efforts, meeting consumer preferences, and promoting increased market demand. The objective of this study was to assess the effect of fruit quality traits and hedonic sensory evaluation on consumers' willingness to pay (WTP) for a selection of fresh northern and southern highbush blueberry cultivars. The WTP was elicited by using a double-bounded contingent valuation conducted in conjunction with a consumer sensory test. Two types of models were estimated using either sensory evaluations (i.e., consumer preference and consumer intensity) or instrumental measurement data (i.e., measures of soluble solids, titratable acidity, sugars, acids, and firmness) as explanatory variables to model WTP. Results using sensory evaluations indicated that flavor liking, flavor intensity, and sweetness intensity are key factors that influence consumers' acceptance and WTP for blueberries. A regression analysis using instrumental measurements indicated that measures related to sweetness and acidity traits are important factors that determine WTP. Higher WTP was associated with higher total sugar content across different levels of total organic acid. The WTP increases with organic acid content, because this is needed for enhanced flavor; however, WTP declines at high concentrations of organic acid. Except for extreme values of firmness, the WTP increased as measures of fruit firmness increased, indicating a consumer preference for firmer blueberries. Overall, the results provided new insights into the relationships between consumer preference and WTP and fruit quality benchmarks to select for improved quality. [ABSTRACT FROM AUTHOR]

Two eggplant cultivars (Brigitte and Dalong) were stored under ambient conditions for 8 days to examine the postharvest quality and shelf life. Results indicated that the respiration rate, firmness and springiness, and nutritional quality of both eggplant cultivars decreased with the extension of shelf life. On the contrary, opposite trends were observed in weight loss, gumminess, and chewiness of eggplant fruits. In addition, the weight loss of 'Brigitte' eggplant fruits was 3.3% and 6.9% lower compared with 'Dalong' eggplant fruits at 4 and 8 days after storage. Thicknesses of epidermal cells and the stratum corneum, the epicuticular wax content of 'Brigitte eggplant fruits increased by 42.9%, 766.7%, and 58.8% compared with 'Dalong' eggplant fruits, respectively, with a concomitant increase in the dense wax layer structure. In conclusion, the storage tolerance of 'Brigitte' eggplant fruits was higher than that of 'Dalong' eggplant fruits due to the higher epicuticular wax content and dense wax layer structure. [ABSTRACT FROM AUTHOR]

The production of cherry tomato (Solanum lycopersicum var. cerasiforme) is negatively affected by harsh environmental conditions such as extremely high and low temperatures, wind and hail damage, and pest and disease infestation. These factors delay maturity and cause uneven ripening, fruit abrasion, and blemishes, which consequently result in poor fruit quality and reduced shelf life. Preharvest bagging is an environmentally friendly alternative technique for enhancement of fruit quality and hence alleviates the stated problems. The study evaluated the physico-chemical quality of ‘Tinker’ and ‘Roma VF’ cherry tomato as influenced by preharvest bagging (transparent and blue plastics) during 8 days of shelf life at ambient conditions. Five clusters of fruit per plant per cultivar with a diameter of 1.5 to 2.0 cm were bagged after 16 days of fruit set and harvested at the green maturity stage, 12 days after preharvest bagging for the assessment of postharvest quality. Preharvest bagging effectively accelerated fruit maturity and ripening as indicated by enhanced fruit size, uniform color development, high pH, dry matter (DM) content, soluble solid content (SSC), and low titratable acidity (TA) during shelf life. Bagged fruit had higher loss of firmness and weight mainly due to ripening and showed very slight incidence of diseases during shelf life of 8 days. Unbagged cherry tomato had delayed maturity and ripening; small-sized fruit; uneven color development; low pH, SSC, and DM; and high TA. Although unbagged cherry tomato had lower firmness and weight loss due to delayed ripening, fruit showed moderate to severe incidence of tomato bacterial canker disease (Clavibacter michiganensis subsp. michiganensis) during shelf life. These results indicated that preharvest bagging accelerated fruit maturity and ripening, improved physico-chemical quality, and reduced disease infestation on cherry tomato during shelf life. [ABSTRACT FROM AUTHOR]

A 6-year trial was established in Oct. 2015 in western Oregon to evaluate the effects of pruning and trellising on yield, hand- and machine-harvest efficiency, fruit quality, and costs of pruning and harvest of ‘Legacy’ highbush blueberry (complex hybrid based largely on Vaccinium corymbosum L. and Vaccinium darrowii Camp.). Pruning treatments began in Winter 2017–18 (before year 3) and continued each year through 2020–21 (year 6). Treatments included 1) recommended pruning for ‘Legacy’, removing less wood and leaving more short, thin laterals and a denser bush than is typical for most northern highbush cultivars (“control” with standard T-trellis), 2) control pruning and training to a V-trellis (“V”), and 3) standard northern highbush style pruning (“HB” with standard T-trellis). Fruit were harvested solely by hand in 2017 and 2018, and by hand for early harvests followed by machine for later harvests from 2019 to 2021. In most years, more wood was removed from HB- than control-pruned plants. On average, HB-pruned plants had a lower yield (6.7 kg/plant) than control-pruned plants, particularly those trained to a V-trellis (7.5 kg/plant). There was little effect of pruning treatment on fruiting season and hand- (7% drop) or machineharvest efficiency (23% drop). Pruning method had no effect on berry weight, diameter, total soluble solids, or firmness over the study period or percent internal bruising in 2019. All of the ‘Legacy’ pruning methods studied required more time (358 to 561 h·ha–1) than the industry standard, ‘Duke’ (247 h·ha–1). Control and HB pruning did not differ in time to prune per unit area; however, in 2 of the 4 years, adding a V-trellis increased pruning time. On average, control and HB pruning had a similar cost per harvested fruit ($0.20 to $0.21/kg), whereas control pruning with a V-trellis ($0.23/kg) cost more than HB pruning. All treatments required the same amount of time to harvest (12.7 and 0.5 min·kg–1 for hand and machine picking, respectively). Total cost to prune and harvest ranged from $1.63/kg in 2019 to $3.43/kg in 2021 but was most heavily influenced by harvest costs rather than pruning. The one-time installation cost of $637/ha for the V-trellis was not compensated for by increased yield or efficiency of pruning or harvest compared with the control method with a standard T-trellis. Pruning according to recommended methods for ‘Legacy’ (control) increased yield without having a negative effect on fruit quality and had similar or lower costs to prune per kg of fruit harvested as typical northern highbush pruning. [ABSTRACT FROM AUTHOR]

A 4-year trial was established in Oct. 2016 in western Oregon to evaluate the effects of various in-row mulch treatments on yield, fruit quality, and costs of installation and maintenance during establishment of northern highbush blueberry (Vaccinium corymbosum L. 'Duke'). The treatments included douglas fir [Pseudotsuga menziesii (Mirb.) Franco] sawdust, black weed mat (woven polypropylene groundcover), green weed mat, and sawdust covered with black or green weed mat. Fruit were harvested during 2018-20 (second through fourth growing seasons). Weed mat color had no effect on yield or fruit quality. In 2018, yield was higher with black weed mat over sawdust mulch than with black weed mat alone, whereas mulch had no effects during 2019 and 2020, or on cumulative yield. Percent total soluble solids in the berries was highest with sawdust and weed mat alone compared with weed mat over sawdust mulches, whereas berry weight, diameter, and firmness were unaffected by mulch. Sawdust was the most expensive mulch over the lifespan of the planting because it required replenishment after 2 years. Black weed mat over sawdust resulted in the highest net profit when fruit sales and cost of materials and labor were considered. [ABSTRACT FROM AUTHOR]

The stability of yield and quality traits in nine orange-fleshed melon (Cucumis melo L.) genotypes was studied over nine environments in south-central Texas (College Station, Uvalde, and Weslaco) over 3 years (2010, 2011, and 2012). Besides yield traits, fruit-quality components such as soluble solids content (SSC), b-carotene, and fruit firmness were also measured. Data were subjected to the combined analysis of variance and trait stability by GGE Biplot. The significant genotype-by-location interactions for yield traits demonstrated the potential to develop location-specific cultivars. However, the temporal fluctuations in productivity emphasized the need to select for stability over several years in potential cultivars for the target environments. Cultivar Mission was confirmed as the most stable and average performing genotype for marketable yield and quality traits at all locations. Uvalde was identified as the ideal location for selecting generally adapted genotypes for south-central Texas. Biplot analysis indicated that Orange Dew was the highest mean performing genotype for SSC. The hybrid Oro Duro, followed by TAMU 146, ranked highest for mean and stability of b-carotene content, but it ranked lowest for fruit firmness. TAMU Orange Casaba exhibited specific adaptation, producing the highest mean fruit yield at Weslaco, while Journey had the highest fruit yield at College Station and Uvalde. Understanding of genotype-by-environment interactions for multiple traits in melon is critical for developing cultivars with high mean performance and stability in target growing environments. [ABSTRACT FROM AUTHOR]

'Minomusume' strawberries were stored in high CO2 atmospheres (20%, 30%, and 40%) by means of a controlled atmosphere (CA) and active modified atmosphere packaging (MAP) for 10 days at 5 °C. The CA of 20% to 40% CO2 was effective in delaying an increase in fungal count and preventing the external formation ofmoldmycelia, but a CA of >30% CO2 induced black discoloration on the surface of strawberry due to CO2 injury. When strawberry fruit were stored in a MAP flushed with either air or high CO2, all packages approached an equilibrium of ≈20% CO2 and 2% O2 by the end of storage. Fungal counts of strawberry fruit stored in a MAP remained constant throughout the storage period and the diversity of fungal flora was partially similar regardless of the difference in the MAP method. Visual quality (mold incidence and severity of black discoloration) and physicochemical quality (weight loss, firmness, pH, and total ascorbic acid content) were unaffected by CO2 atmospheres as the flushing gas during active MAP storage, except that the fruit in a MAP flushed with 20% and 30% CO2 were firmer than those with air and 40% CO2. After transfer to ambient conditions for 6 days at 10 °C, however, external formation ofmoldmycelia identified as Botrytis cinerea and surface black discoloration were induced in strawberry fruit in MAP flushed with 30% and 40% CO2. [ABSTRACT FROM AUTHOR]

Ripening and development of physiological disorders and decay were assessed in 'd'Anjou' pear fruit after 1-methylcyclopropene (1-MCP) treatment and cold storage in air or controlled atmosphere (CA). Fruit were exposed after harvest to 0 or 12.6 µmol·L-1 1-MCP and then stored at 0.5 °C in air or 1, 3, or 5 kPa O2 with 0.5 kPa CO2. Pears were held poststorage at 20 °C for 7 days before analysis. 1-MCP fruit usually had higher hue compared with controls. Softening after removal from storage was delayed in 1-MCP fruit regardless of storage atmosphere; however, control fruit stored in air or CA ripened to below 23 N, a minimum value for consumer acceptance, after all storage durations. 1-MCP fruit stored in air, 3, or 5 kPa O2 softened in the outer cortex (fruit surface to 8 mm into the cortex) to below 23 N only after 9 m, however, only fruit stored in air softened to less than 23 N in the inner cortex (8 mm to coreline). 1-MCP treatment also delayed deformation in cortex tissue tensile strength (TTS); after six or more months, 1-MCP fruit TTS was lower compared with those for control fruit. After 9 m, 1-MCP fruit stored in air had TTS values similar to those of controls whereas values for fruit stored in CA increased with CA O2 concentration. Titratable acidity was higher in 1-MCP-treated fruit stored in air (6 m only) or 3 or 5 kPa O2 compared with controls. Superficial scald developed after 6 m on control fruit stored in air or 5 kPa O2 and on control CA fruit regardless of O2 concentration after 9 m. No 1-MCP fruit developed scald. The results indicate 'd'Anjou' pear ripening in response to 1-MCP is influenced by storage pO2 as well as storage duration, and at the 1-MCP treatment concentration used, softening to a consumer standard for firmness occurred only in fruit cold stored in air for 9 months plus a 7-day poststorage ripening period. These fruit had peel hue less than 100, and the yellow peel color may not be consistent with current market expectations. [ABSTRACT FROM AUTHOR]

Fruit firmness is among the most important characteristics for the quality of sweet cherries. However, little has been published on its underlying frequency distribution. This research was undertaken to examine the firmness distributions (n = 48) from six cultivars [Sandra Rose, Summit, Lapins, Skeena, Sumtare (Sweetheart™), and 13S2009 (Staccato™)], two field treatments [with or without gibberellic acid (GA)], two storage times (0 and 7 days), and two growing seasons (2013 and 2014). Fruit was sampled (n = 300) at optimal maturity and firmness was evaluated using the FirmTech2 Fruit Firmness Tester. Firmness distributions were examined using descriptive statistics: mean, median, standard deviation (SD), minimum, maximum, range, skewness, and excess kurtosis. Nonnormality was assessed using skewness and kurtosis test statistics. Exponential models were fitted to the ascending and descending portions of the distributions and the proportion of ''too soft'' (percentage < 2.56N·mm–1) and ''too hard'' (percentage > 4.71 N·mm–1) fruit was determined. A relatively high proportion of distributions were nonnormal (16/24 to 18/24), either skewed, peaked, or both. While most skewed distributions were skewed negatively, with a higher proportion of softer fruit, the distributions for 'Sandra Rose' were skewed positively, with a higher proportion of firmer fruit. Principal component analysis (PCA) showed seasonal, cultivar, treatment, and storage effects among three subsets of cultivars with differing characteristic firmness. The softer early-harvest cultivars (Sandra Rose and Summit) had a higher proportion of ''too soft'' fruit. GA and storage treatments increased mean firmness and reduced the proportion of ''too soft'' fruit. The firmer late-harvest cultivars (Skeena, Sumtare, and 13S2009) had a small proportion of ''too hard'' fruit (0% to 19.3%). The work gained insight into the nature of the firmness distributions for sweet cherries and the type of statistics that are most appropriate for analyzing the data. [ABSTRACT FROM AUTHOR]

The University of Arkansas (UA) blackberry breeding program began in 1964, with the aim to provide high-quality fruit to the fresh market industry. One of the important traits for successful blackberry (Rubus subgenus Rubus Watson) postharvest handling is flesh firmness, so developing cultivars with high firmness is a top priority for the fresh market blackberry breeding programs across the world. In particular, the Arkansas blackberry program has a wide range of genotypes with exceptional firmness characteristics, including fruit with a unique crispy texture and firmness. During 2013 and 2014, fruit firmness measurements were done on 15 Arkansas genotypes including those with crispy and noncrispy textures. Firmness measurements consisted of fruit compression, skin drupelet penetration, and receptacle penetration. Confocal photos were taken on sections of berries of a subset of crispy and noncrispy genotypes, and color reversion was evaluated among these genotypes after storage. Compression force values differentiated crispy and noncrispy genotypes, with average values of 11.8 Newton (N) and 8.0 N, respectively. Drupelet penetration force was also higher for crispy genotypes averaging 0.23 N and noncrispy 0.15 N; similarly, receptacle penetration force averaged 0.20 N for crispy and 0.18 N for noncrispy genotypes. Visual inspection of fruit tissue revealed that drupelet mesocarp cells and receptacle cells and cell walls of crispy genotypes maintained their structure during ripening and did not break apart, whereas noncrispy genotypes did not maintain their structure and cellular integrity. Color reversion is a postharvest disorder in which drupelets of blackberry fruits turn red after being black at harvest. Therefore, it has a negative impact for growers, shippers, and consumers. After storage at 5 °C for 7 days, crispy genotypes expressed low levels of reversion compared with noncrispy genotypes. For crispy genotypes, 13.2% of drupelets developed color reversion, whereas a 41.0% developed this disorder in noncrispy genotypes, implying a better postharvest potential of this texture. [ABSTRACT FROM AUTHOR]

Four blackberry (Rubus L. subgenus Rubus Watson) cultivars ('Obsidian', 'Black Diamond', 'Metolius', 'Onyx') and two advanced selections (ORUS 1939-4 and ORUS 2635-1) were evaluated during the establishment years of an organic production system for fresh market. The planting was established in Spring 2010 using approved practices for organic production and was certified organic in 2012, the first fruiting year. Plants were irrigated using a dripline under a woven polyethylene groundcover (weed mat) installed for weed management. Liquid fertilizers injected through the drip system were used at rates of 56 kg⋅ha-1 total nitrogen (N) in 2011-12 and 90 kg⋅ha-1 total N in 2013. Genotypes differed in the level of nutrients measured in primocane leaves. Tissue phosphorus (P), potassium (K), sulfur (S), iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) concentrations were within the recommended standards, but tissue calcium (Ca), magnesium (Mg), and boron (B) were deficient in some or all genotypes. Although two cultivars and both advanced selections responded well in terms of plant growth and yield to the organic production system used, yields in 'Onyx' and 'Metolius' were considered low for commercial production. In contrast, the higher yielding 'Obsidian' and ORUS-2635-1 appeared to be the best suited for organic fresh market production as a result of larger fruit size, greater fruit firmness, higher sugar-to-acid ratios, lower post-harvest percent moisture loss in ORUS-2635-1, and the longest number of marketable storage days at 5 °C in 'Obsidian'. [ABSTRACT FROM AUTHOR]

Establishing marker-locus-trait associations to enable marker-assisted breeding depends on having an extensive, reliable database for phenotypic traits of interest in relevant germplasm. A reference germplasm set of 467 apple (Malus x domestica Borkh.) cultivars, selections, and seedlings (referred to as individuals) was identified as part of the USDA-Specialty Crop Research Initiative (SCRI) project, RosBREED. The germplasm set provides efficient allelic representation of current parents in RosBREED demonstration apple breeding programs at Cornell University, Washington State University, and the University of Minnesota. Phenotyping at the three locations was conducted according to standardized protocols, focusing on fruit traits evaluated at harvest and after 10 and 20 weeks of refrigerated storage. Phenotypic data were collected for the sensory texture traits of firmness, crispness, and juiciness as well as for instrumental texture measures. In 2010 and 2011, fruit from 216 and 330 individuals, respectively, were harvested and a total of 369 individuals were evaluated over the two years. Correlations between sensory and instrumental texture measures were high in some instances. Moderate year-to-year repeatability of trait values was observed. Because each location had a largely unique set of individuals, as well as differing environmental conditions, means, ranges, and phenotypic variances differed greatly among locations for some traits. Loss of firmness and crispness during storage was more readily detected instrumentally than by the sensory evaluation. [ABSTRACT FROM AUTHOR]

A postharvest 1-methylcyclopropene (1-MCP) treatment was evaluated for its ability to maintain firmness and delay the ripening of rabbiteye blueberries. Three cultivars, Austin, Brightwell, and Premier, were harvested by hand from the UGA Alapaha Blueberry Farm and treated overnight with 1 µL⋅L-1 1-MCP as field heat was being removed [0 to 1 °C, 90% to 95% relative humidity (RH)]. Fruit were evaluated for firmness, total soluble solids (TSS), total acidity (TA), ethylene production, and other quality attributes at 0, 1, and 2 weeks after harvest as well as 1 or 4 days post-removal evaluations at room temperature ≈21 °C). In general, the 1-MCP treatment resulted in the stimulation of ethylene production in all three cultivars but had minimal effect on TSS and TA content. Furthermore, the treatment resulted in an accelerated loss of firmness in 'Brightwell'. The lack of inhibition of fruit ripening likely related to the fact that blueberries were harvested, and subsequently treated with 1-MCP, at a post- climacteric stage of development. Based on current results, more information is required regarding ethylene production during rabbiteye blueberry fruit maturation before establishing a 1-MCP treatment recommendation for use by the rabbiteye blueberry industry. [ABSTRACT FROM AUTHOR]

Apple maturity is often assessed by starch hydrolysis index, skin color, soluble solids, flesh firmness, and the rate of ethylene evolution, in red-fruited apple cultivars, the intensity and extent of coloration is an important consideration in determining the time of fruit harvest. Negative relationships have been found between tree nitrogen (N) status and fruit skin pigmentation, but how N affects flesh starch breakdown has not been examined in detail. The objective of this study was to determine how N supply affects flesh starch breakdown relative to skin color development. Seven-year-old 'Gala'/M.26 trees were provided with four levels of N (8.8, 26.4, 52.7, and 105.4 g N per tree) in a modified Hoagland's solution. The effects of N supply on yield, fruit quality, and fruit maturation were evaluated. At harvest, fruit in the lowest N treatment was significantly smaller and had lower soluble solids but higher starch concentration, better color, and higher firmness than those grown at higher N supplies. Increasing N supply decreased both anthocyanin synthesis and chlorophyll degradation in fruit skin. Flesh starch concentration was higher at higher N supply at 38 days before harvest but was lower at higher N supply at harvest. Starch degradation was completed earlier during cold storage with increasing N supply. These results indicate that increasing N supply delays skin red color development but accelerates flesh starch degradation in 'Gala' apples. These differential effects of N supply should be taken into account when assessing fruit maturity for optimizing harvest time. [ABSTRACT FROM AUTHOR]

The effect of two fruit maturity, stages on the quality attributes of four fresh fig cultivars was examined, including consumer acceptance and antioxidant capacity. Fig quality attributes such as weight, soluble solids concentration (SSC), titratable acidity (TA), SSC:TA, firmness, antioxidant capacity, and consumer acceptance varied by cultivar. Fig cultivars harvested at the advanced maturity stage ("tree ripe") had lower TA and firmness but higher weight, SSC, and SSC:TA than figs harvested at "commercial maturity." Fig maturity did not affect antioxidant capacity, but tree ripe figs had higher consumer acceptance than commercial maturity figs. SSC was more highly correlated with consumer acceptance than TA or SSC:TA, but other factors may also be important in controlling this relationship. Cultivars with high SSC and firmness, at a maturity stage high enough to tolerate harvesting and postharvest handling, should be selected to develop the fresh fig industry. Because fig firmness is a concern, changes to packaging should be evaluated to protect the flavor of advanced maturity figs during postharvest handling. [ABSTRACT FROM AUTHOR]

The impact of heat plus aminoethoxyvinylglycine (AVG) treatments alone or in combination on ripening of four apple cultivars has been studied. A solution of AVG was applied to 'Lodi', 'Senshu', 'Redchief Delicious', and 'Red Fuji' apple trees ≈4 weeks before normal harvest at 124 g-ha-1 a.i. After harvest, half of each group of control and AVG-treated fruit was heated at 38 °C for 4 days and then stored at 4 °C for 30 days. After cold storage, AVG and heat individually suppressed ethylene production of 'Senshu' and 'Redchief Delicious' but not of 'Lodi' or 'Red Fuji'. The combination of AVG with heat treatment reduced ethylene production the most consistently in each cultivar except 'Lodi', suggesting some additive effect of the treatments. The respiration rate after cold storage was not consistently affected by any treatment. AVG alone and with heat maintained firmness of 'Lodi', AVG plus heat maintained it in 'Senshu', but neither 'Redchief Delicious' nor 'Red Fuji' firmness responded to the treatments. AVG-treated 'Lodi' and 'Redchief Delicious' fruit, heated fruit of all cultivars, and AVG plus heat in all had lower titratable acidity than controls after cold storage. Although there were no effects of any treatment on fruit soluble solids concentration, the combined treatment increased the soluble solids:titratable acidity ratio of all cultivars, although heat or AVG alone had no consistent effects. Total ester production by 'Redchief Delicious' peel tissue after cold storage was reduced 44% by AVG and 70% or more by heat and AVG plus heat. There were no differences in peel alcohol acyltransferase activity among the treatments, supporting the hypothesis that substrate availability was the limiting factor for ester synthesis in treated fruit. Overall, heat plus AVG treatment did not provide any advantage over each alone for maintaining apple fruit quality during short-term cold storage. [ABSTRACT FROM AUTHOR]

Preharvest application of Phellodendron bark (Phellodendron chinese Schneid) extract (PBE) on brown rot and postharvest quality of peach [Prunuspersica (L.) Batsch var.platycarpa (Decne.) L.H. Bailey] Was investigated. PBE at 0.8, 1.6, and 3.2 mg·mL-1 totally inhibited conidial germination, mycelial growth, and sporulation, respectively, of Monilinia fructicola in vitro. Preharvest PBE treatment at 21.0 mg·mL-1 at 0, 30, 60, and 90 days after full bloom controlled brown rot caused by M. fructicola on peach fruit after harvest and reduced disease incidence and lesion diameter by 37% and 61%, respectively, than those of the control 96 h after inoculation in in vivo experiments. The results from field experiments were consistent during a 3-year period. Fruit from PBE-treated trees showed higher activities of defense enzymes, including peroxidase, phenylalanine ammonia-lyase, chitinase, and β-1,3-glucanase, compared with those of the control during storage. PBE also delayed softening and loss of titratable acidity and inhibited flesh browning during storage. Total soluble solid contents were unaffected by treatment. The results indicate that preharvest application of PBE may be an alternative for controlling brown rot of peach fruit. [ABSTRACT FROM AUTHOR]

Changes in turgor and flesh firmness during storage at 20 °C were investigated using 27 apple (Malus xdomestica Borkh.) cultivars for 2 years. Flesh firmness was measured using a penetrometer, and turgor was determined using a thermocouple psychrometer. Firmness and turgor of fruit decreased during storage. The cultivars with little softening during storage had low rates of reduction in turgor. The softening rates in mealy cultivars were high, but there were cultivars with low rates of turgor reduction. When the rates of reduction in turgor after harvest were low, the mealy cultivars of the fruit tended to develop severe mealiness during storage. Therefore, a low rate of reduction in turgor could contribute to cultivars with both good shelf life and severe mealiness. The reduction rates of turgor in progeny cultivars were nearly identical to the mean reduction rates of turgor of their parents. This suggests that a cultivar with a low reduction rate of turgor, although it can be mealy, has the potential to produce a progeny with a low reduction rate of turgor. [ABSTRACT FROM AUTHOR]

To compare changes in fruit quality during cold storage with those during shelf life conditions, flesh firmness and titratable acidity (TA) were measured during storage in 20 apple (Malus xdomestica Borkh.) cultivars. Fruit of each cultivar were divided into two groups and stored in chambers controlled at 20 ± 2 °C and 85 ± 5% relative humidity (RH) (shelf life conditions) or 0.5 ± 0.3 °C and 95 ± 5% RH (cold storage). Five of the stored fruit were removed for measurements at 5- or 10-d intervals for 40 d and at 1-month intervals until 10 months after harvest at 20 °C and 0.5 °C, respectively. Data for firmness and TA were subjected to a linear regression and a nonlinear regression, respectively. Moreover, to determine the advantages of 0.5 °C storage over 20 °C storage for retaining firmness and TA, the effect of storage type on extending the storage period was introduced as a parameter. The estimate of the effect of storage type showed that firmness and TA could be retained 8.9 and 3.7 times, respectively, longer at 0.5 °C than 20 °C, independently of the cultivar. Therefore, firmness and TA after cold storage could be predicted by the change in firmness and TA during shelf life conditions. Moreover, cultivar differences regarding quality change under cold storage could be determined in a short period after harvest because the cultivar differences under shelf life conditions were detected within 1 month after harvest. [ABSTRACT FROM AUTHOR]

Sandy soils in the onion (Allium cepa L.) growing region of southeastern Georgia are generally low in calcium (Ca). Bulbs grown in these soils are often soft and susceptible to postharvest diseases. Preliminary greenhouse studies have indicated that supplemental calcium chloride (CaCl2) can improve bulb firmness. The effects of supplemental CaCl2 on the quality of field-grown onions were therefore investigated. Other preliminary studies indicated that CaCl2 may inhibit sulfur (S) uptake in onion and decrease bulb pungency. Thus, ammonium sulfate (NH4)2SO4 and CaCl2 levels were varied to determine if CaCl2 could improve flavor at different levels of nitrogen (N) and S fertility. Onions, cv Georgia Boy, were grown with 0, 250, and 500 kg⋅ha-1 (NH4)2SO4 and 0, 115, and 230 kg⋅ha-1 CaCl2 in a factorial combination in 2005 and 2006. Total bulb yield increased with increasing (NH4)2SO4, but was unaffected by CaCl2. The percentage of diseased bulbs increased during storage in both years, and was affected by (NH4)2SO4 fertility in 2006. Bulb scale firmness increased with supplemental CaCl2 fertility and decreased significantly during storage in both years. Fertility treatments had little effect on bulb pectin composition, although total pectin concentrations fell during storage in 2005 and 2006. In addition, bulb pungency decreased with additional CaCl2 in 2006. However, CaCl2 had a limited effect on flavor precursor concentrations. There were no interactions between fertility treatments, but there were CaCl2 and (NH4)2SO4 by storage duration interactions affecting firmness and disease incidence, respectively. With the exception of yield, differences among years in the parameters measured were generally small. [ABSTRACT FROM AUTHOR]

Studies were conducted over three seasons to determine the relationship of temperature and humidity on the storage life of fresh cranberry (Vaccinium macrocarpon Aiton) fruit. Each year, cranberries harvested from four commercial bogs were stored at temperatures ranging from 0 to 10 °C in combination with relative humidities (RH) ranging from 75% to 98%. Fruit were stored under these conditions for up to 6 months and were evaluated monthly for marketability, decay, physiological breakdown, weight loss, and firmness immediately after removal and after an additional week at 20 °C. The percentage of marketable fruit declined substantially over time in all storage conditions with 41% to 57% becoming unmarketable after 2 months as a result of both decay and physiological breakdown. Relative humidity had a greater effect on fruit storage life than temperature and after 5 months, the amount of marketable fruit stored in high (98%) and medium (88%) RH was 71% and 31% less than that stored in low (75% to 82%) RH. Rates of fresh weight loss increased as RH in storage decreased and was 0.41%, 0.81%, and 0.86% per month in fruit stored in high, medium, and low RH, respectively. Fruit firmness was not significantly affected by RH. The effects of storage temperatures ranging from 0 to 7 °C on marketable fruit after 2 to 5 months of storage were not significant. Only fruit stored at 10 °C consistently had fewer marketable fruit when compared with fruit stored at lower temperatures. Storage temperature had no significant effect on decay incidence. However, physiological breakdown was greatest in fruit stored at 10 °C. Rates of fresh weight loss increased with storage temperature, ranging from 0.35% to 1.17% per month for fruit stored at 0 to 10 °C, respectively. Contrary to previous reports, no evidence of chilling injury was found in cranberry fruit stored at 0 °C. Results suggest that cranberry fruit should be stored at 0 to 7 °C and 75% to 82% RH to retain marketable fruit. [ABSTRACT FROM AUTHOR]

Apple [Malus xsylvestris (L.) Mill. var. domestica (Borkh.) Mansf. 'Cripps Pink'] fruit were harvested yearly, at two or three maturity stages, from the same California orchard in 2002 through 2005. Fruit firmness, soluble solids, titratable acidity, background color, and percent blush were correlated with the starch pattern index at harvest. Fruit from each harvest were stored at 0.5 °C in air or in a controlled atmosphere (CA) with 1.5 or 2 KPa O2 in combination with 1, 3, and 5 KPa C2. Subsets of fruit were treated with 1 µL⋅L-1 1-methylcyclopropane for 24 hours at 0 °C or 2200 µL⋅L-1 diphenylamine (DPA) for 5 minutes. Ethylene production was measured for 30 days after harvest. Ethylene concentration in the storage atmosphere was also monitored during storage. Fruit quality was evaluated after storage plus 5 days of ripening at 20 °C. Fruit in a CA with 1 or 3 KPa C2 maintained firmness and green background color, and produced less ethylene during ripening at 20 °C than fruit stored in a CA with 5 KPa CO2; however, quality of all CA-stored fruit was better than air-stored fruit. Flesh browning developed only in CA storage, appearing by 2 months and not increasing in incidence with further storage periods. 1-Methylcyclopropane conserved fruit quality in air as well as CA during 4 months of storage, and DPA-treated fruit were firmer after CA storage, but similar after air storage, compared with untreated fruit. Diphenylamine did not control a stem-end scald disorder, which increased with time in storage and affected more than 80% of the fruit after 6 months of air storage. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine whether aminoethoxyvinylglycine (AVG), an inhibitor of ethylene synthesis, would affect earliness, increase yield, and improve overall at harvest and postharvest quality of melon (Cucumis melo L. group Cantalupensis, 'Sol Real'). Field experiments were conducted during two seasons with AVG (124 g⋅h-1 a.i.) applied as spray or soil injected into the root zone with a single or double application between 7 d and 21 d before harvest. The AVG soil injection method increased earliness compared with AVG spray in one season. Total marketable yield increased with AVG injection but not with the AVG spray method compared with the control. Regardless of method of application, AVG did not affect fruit firmness, rind thickness, netting, or soluble solids content when measured at harvest. However, AVG spray decreased fruit size and seed cavity, in one season. Similarly, AVG spray did not affect fruit quality after storage, whereas AVG soil injection increased fruit firmness. Overall, melon yield and fruit quality responses to preharvest AVG applications were superior for the soil injection than the spray method. [ABSTRACT FROM AUTHOR]

Netted muskmelon [Cucumis melo L. (Reticulatus Group)] fruit quality (ascorbic acid, β-carotene, total free sugars, and soluble solids concentration (SSC)) is directly related to plant potassium (K) concentration during fruit growth and maturation. During reproductive development, soil K fertilization alone is often inadequate due to poor rout uptake and competitive uptake inhibition from calcium and magnesium. Foliar applications of glycine-complexed K daring muskmelon fruit development has been shown to improve fruit quality, however, the influence of organic-complexed K vs. an inorganic salt form has not been determined. This glasshouse study investigated the effects of two K sources: a glycine-complexed K (potassium metalosate, KM) and potassium chloride (KCI) (both containing 800 mg K/L) with or without a non-ionic surfactant (Silwet L-77) on melon quality. Orange-flesh muskmelon 'Cruiser' was grown in a glasshouse and fertilized throughout the study with soil-applied N-P-K fertilizer. Starting at 3 to 5 d after fruit set, and up to 3 to 5 d before fruit maturity at full slip, entire plants were sprayed weekly, including the fruit, with KM or KCI with or without a surfactant. Fruit from plants receiving supplemental foliar K had significantly higher K concentrations in the edible middle mesocarp fruit tissue compared to control untreated fruit. Fruit from treated plants were also firmer, both externally and internally, than those from non-treated control plants. Increased fruit tissue firmness was accompanied by higher tissue pressure potentials of K treated plants vs. control. In general, K treated fruit bad significantly higher SSC, total sugars, total ascorbic acid, and β-carotene than control fruit. Fall-grown fruit generally had higher SSC, total sugars, total ascorbic acid and βcarotene concentrations than spring-grown fruit regardless of K treatment. The effects of surfactant were not consistent but in general, addition of a surfactant tended to affect higher SSC and β-carotene concentrations. [ABSTRACT FROM AUTHOR]

'Bing' sweet cherry (Prunus avium L.) trees were treated with hydrogen cyanamide (CH2N2) or calcium ammonium nitrate (CaNH4NO3) during dormancy, or gibberellic acid (GA3) 26 days before harvest during three consecutive years. Fruit were evaluated at harvest for sensory taste quality using twenty trained panelists sampling for firmness, sweetness, tartness, and cherry flavor. Nondestructive instrumental firmness preceded destructive sensory firmness on the same untreated and GA3-treated cherries in one year when used as a supplementary evaluation. Sensory firmness was consistently higher in GA3 fruit and to a lesser extent in CH2N2 fruit than in CaNH4NO3 and untreated fruit. Instrumental firmness of GA3 fruit did not increase significantly compared with untreated fruit yet instrumental firmness of each treatment correlated relatively well with perceived sensory firmness. Sensory sweetness and cherry flavor scored very similarly, yet both attributes simultaneously varied between treatments across the years. Perceived sensory tartness of treated fruit was variable among years; yet, on average, was rated among treated and untreated fruit as similar. Under the assumption that elevated sensory firmness, sweetness, and cherry flavor intensity reflects improved sweet cherry quality, GA3 fruit were rated of higher quality than untreated fruit given their increased firmness and similar or occasionally elevated sweetness and cherry flavor intensity. CH2N2 fruit maintained quality similar to that of untreated fruit, despite often having marginally higher firmness, due to similar or reduced ratings for sweetness and cherry flavor intensity. Notwithstanding similar firmness between CaNH4NO3 and untreated cherries, sensory quality of CaNH4NO3-treated cherries was reduced due to their often-diminished levels of perceived sweetness and cherry flavor. [ABSTRACT FROM AUTHOR]

During storage, many apple (Malus ×domestica Borkh.) genotypes lose their desirable textural qualities, but some like 'Honeycrisp', maintain their sensory Crispness and Firmness. To understand this differential response of genotypes to postharvest changes in texture, reliable and quantifiable methods of texture measurement are needed. This study integrated data from a snapping test, confocal laser scanning microscopy (CLSM), and sensory panels to study postharvest textural changes and to predict sensory textural attributes of Firmness, Crispness, Mealiness, and Juiciness. Three separate analyses on fresh, stored, and combined fresh and stored fruit data yielded different predictors for the same sensory attributes. Change in Crispness during storage was successfully predicted by change in Work during storage. Cell number and size were related to fresh fruit texture and its maintenance during storage. Unique textural properties of 'Honeycrisp' were found to be inherited by its progeny. [ABSTRACT FROM AUTHOR]

Apples [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf. ('Gala', 'Delicious', 'Granny Smith' and 'Fuji')], pretreated or nontreated with 1-methylcyclopropene (1-MCP, 0.6 to 1.0 µL·L-1 for 18 hours at 20 °C), were stored in controlled atmosphere (CA, 1 to 1.5 kPa O2; 1 to 2 kPa CO2) or in regular atmosphere (RA) for up to 8 months at 1 °C. Firmness, titratable acidity (TA), soluble solids content (SSC), and volatile abundance were analyzed every month directly or after transfer to air at 20 °C for 1 week to determine effect of 1-MCP, storage atmosphere and storage time on apple quality immediately after cold storage and after simulated marketing conditions at 20 °C. The 1-MCP ± CA treatments delayed ripening and prolonged storage life as indicated by delayed loss of firmness and TA in all four cultivars during storage. The 1-MCP ± CA also slightly delayed loss of SSC for 'Gala' but had no effect on SSC levels for the other cultivars. There were differences among treatments for firmness and TA content [(1-MCP + RA) > CA] for 'Gala', 'Delicious', and 'Granny Smith' apples, but not for 'Fuji'. These differences were generally exacerbated after transfer of fruit to 20 °C for 1 week. A combination of 1-MCP + CA was generally best [(1-MCP + CA) > (1-MCP + RA) or CA] for maintaining 'Delicious' firmness and TA. However, the treatments that were most effective at retaining TA and firmness also retained the least volatiles. The results indicate that the efficacy of 1-MCP and CA in maintaining apple quality factors is cultivar dependent and that 1-MCP + RA may be a viable alternative to CA for optimal eating quality for some cultivars. [ABSTRACT FROM AUTHOR]

A convenient and reliable method that used a specially designed tool to apply a uniform bruising force in situ was developed to assess the relative susceptibility to fruit surface pitting in sweet cherry. Assessment of pitting with a visual scale after 2 weeks of 1 ° C storage was found to be in close agreement with measurements of pit diameter. Using this method 'Bing' showed the greatest susceptibility to pitting in both years of the study and 'Bing', 'Lapins', and 'Sweetheart' cherries showed a decline in susceptibility as fruit matured. The predictive value of fruit firmness at harvest, fruit respiration at harvest, and weight loss in storage was assessed in relation to the severity of pitting. The model to best describe pitting was found to include all three physiological variables (firmness, respiration, and weight loss). While an acceptable model was obtained when combining all three cultivars, the best models were achieved when each cultivar was considered separately. It was concluded that there are likely unmeasured variables involved in determining susceptibility to pitting. Hence the best approach to predicting pitting susceptibility is the application of the pit-induction method described in this work. [ABSTRACT FROM AUTHOR]

'Mclntosh' apples (Malus x domestica Borkh.) display a rapid increase in ethylene production as they ripen, resulting in more preharvest drop and accelerated softening compared with other major cultivars. Economic considerations often dictate a choice between delaying harvest to achieve color development or harvesting earlier to avoid excessive fruit softening and drop. We have evaluated the effects of plant growth regulators (PGRs) and summer pruning on this balance. Treatments were applied to trees in the Mid-Hudson region in New York state in 1995 and 1996, and a subset of treatments was applied in the Champlain Valley region in 1996. NAA, applied at 10 mg⋅L[sup-1] in 1995 and 20 mg⋅L[sup-1] in 1996, reduced drop on only one sample date in only one of the three trials. Ethephon at 150 mg⋅L[sup-1] plus 10 mg⋅L[sup-1] NAA, accelerated ripening and permitted harvest before substantial drop occurred. However, earlier harvest resulted in smaller fruit size, and if ethephon-treated fruit were not picked within a narrow window, rapid drop ensued, and fruit developed a high senescent breakdown incidence during storage. ReTain, containing AVG, at 124 g⋅ha[sup-1] a.i. delayed drop in all three trials, but its use resulted in firmer fruit after storage in only two of seven comparisons. Use of ethephon on AVG-treated trees enhanced red color but accelerated drop, although it was reduced less than when ethephon was used alone. Severe late summer pruning accelerated red color development, drop and ripening in both years of the study. AVG was more effective for management of 'McIntosh' harvest in the cooler Champlain Valley region than in the Mid-Hudson Valley region. Chemical names used: naphthalene acetic acid (NAA); 2-chloroethylphosphonic acid (ethephon); aminoethoxyvinylglycine (AVG). [ABSTRACT FROM AUTHOR]