Brief Summary of Minutes of Annual Meeting

Objective 1: Storage disorders were evaluated in Honeycrisp apples harvested from irrigated and unirrigated trees and stored in air at 1 °C for 4 months. Differences in soil water were not great. Irrigation had no effect on occurrence of soft scald (43%), but it reduced soggy breakdown from 11% to 3% [ME]. Storage disorders were evaluated in Honeycrisp apples harvested from six different orchards that varied in fertility and stored 4 months in air at 1 °C. There were large variations among orchards in the occurrence of soft scald and soggy breakdown, but there was no correlation with foliar levels of nutrients (N, P, K, Mg, Ca, B, Zn, Mn, Fe and Cu) [ME]. A 5-day delay in cooling after harvest was tested alone or combined with 1-MCP treatment or CA storage as a means of reducing storage disorders in Honeycrisp apples. CA was also tested alone or combined with 1-MCP. Delayed cooling reduced soft scald from 41% to 7%. There was also a low incidence of soft scald in CA-stored fruit (5%), likely due to storage at 3 °C rather than 1 °C. No treatment reduced the occurrence of soggy breakdown. Scores from sensory evaluation were not affected by delayed cooling and did not vary between treatments for appearance, color, flavor, texture and overall rating [ME]. Effects of 1-MCP, DPA, delayed cooling, and storage temperature on quality of Honeycrisp apples stored for 5 months in air were evaluated. No treatment or factor or combination thereof altered the incidence of soft scald. Bitter pit was reduced by 1-MCP (1 ppm) and increased by 4.5 °C (vs. 1.5 or 3 °C) storage. An increase in the incidence of lenticel breakdown (LB) induced by 1-MCP was exacerbated by delayed cooling (4 days at 21 °C), whereas DPA treatment reduced LB but increased the occurrence of storage rots. Storage temperature had the greatest influence on fruit firmness; apples stored at 1.5 °C were softer than those stored at 3 or 4.5 °C [ON]. Apple fruit from 184 lines of Core Collection of the USDA Apple Germplasm Repository in Geneva, NY were assessed for aroma production, ripening date and storability. Several lines possessed unusual aroma character. Storability, based on firmness retention, was normally distributed. Several lines possessed high firmness and freedom from storage defects [MI]. To select new apple varieties for fresh-cut processing, the browning potential of Ambrosia, Aurora Golden Gala, Galarina, Goldrush, Honeycrisp, and Eden apples was evaluated after 1 and 3 months of air storage at 0-1 °C. Fruit slices in plastic bags were held at 5 °C for 1 week and then visually assessed for surface browning. Overall, Eden apples from Quebec showed the least amount of browning; Ambrosia and Imperial Gala grown in British Columbia also showed a low level of browning. Growing location may be a key factor in browning potential, although slices of Honeycrisp and Aurora Golden Gala fruit from both BC and Ontario browned rapidly [ON]. Post-storage quality of Clemenules Clementine and W. Murcott mandarins (waxed and fungicide-treated) was best when these fruits were stored in air at 5 ºC and 90-95% relative humidity for up to 8 weeks [CA]. Respiration rates of Autumn Olive (Elaeagnus umbellata), a small berry high in lycopene and total phenolics, were measured to determine the best holding temperature prior to processing and were found to be in the low to moderate range (5-8 mg/kg/h at 2 °C and 39-50 mg/kg/h at 25 °C) [USDA-OK]. Objective 2: Use of MAP bags to enclose pallets of stored Bartlett pears maintained green color in storage, resulted in higher fruit firmness, reduced decay incidence, and reduced senescent scald and internal browning in the longer storage periods. Further studies are required to optimize the benefits of using MAP pallet shrouds [CA]. Various silicone-based surfactants or defoamers were tested on California Bing sweet cherries as disinfestation agents. None of the treatments adversely affected fruit quality, and the defoamer 360 EFG was most effective with respect to mite removal and mortality [CA]. Radio frequency (RF) heating was tested as an alternative quarantine treatment for control of Mexican fruit fly larvae in Fuyu persimmon and Vernon white sapote fruit. Adverse effects of RF heating to 48 °C (internally) for several minutes were minimal. Internal browning after 2 months at 0 °C was no different in RF-heated and control persimmons. RF heating accelerated ripening of white sapote fruit, but did not reduce levels of sugars or ascorbic and citric acids. Preliminary tests were also conducted to determine the feasibility of using RF heating for quarantine treatment of stone fruit to control codling moth larvae [CA]. Work continued to develop and evaluate promising ethyl formate-based treatments to control arthropod pests on California table grapes. Inclusion of 45% CO2 in the VaporMate" formulation registered for insect control in Australia did not reduce the efficacy of ethyl formate against grape mealybug eggs or Pacific spider mites [CA]. Atmosphere, temperature and maturity relationships with internal browning disorders of McIntosh and Empire apples are being investigated. No clear patterns have emerged except for higher susceptibility to injury in later harvested fruit [NY-I]. Compared with dark-grown cultures, blue light suppressed mycelial growth and sporulation in the postharvest apple pathogen Penicillium expansum, and reduced production of the toxin patulin by 20-fold. In contrast, red light stimulated patulin production by 40-fold. Patulin does not contribute to the progression of apple spoilage, but it does pose a human health risk, particularly in juice products [NY-I]. Gluconobacter asaii (a plant pathogen antagonist from apple fruit) and a bacteriophage cocktail were tested as biocontrol agents against Listeria monocytogenes on fresh-cut honeydew melon. G. asaii alone reduced L. monocytogenes populations by 3-4 log units and phage alone by 1 log unit over 7 days at 10 °C. The two agents were most effective when combined, reducing L. monocytogenes populations by 1 log at day 2 and by nearly 6 log units at day 7 [USDA-MD]. A manually operated high-pressure hot-water washing system was tested on Anjou pears. The high-pressure wash was effective in removing surface pests and limiting postharvest decay with minimal external or internal damage when the water was <30 °C, a wetting agent and a defoamer were included, and rotating soft brushes were used [OR-HR]. Thermofogging of Anjou pears with the scald inhibitor ethoxyquin plus the fungicide pyrimethanil was tested as a means to control scald and storage rot with lower levels of chemical residues. The treatment was slightly less effective in controlling scald than a drench with 1000-1500 ppm ethoxyquin. There was no negative interaction with the fungicide, and phytotoxicity was significantly reduced [OR-HR]. Pyrimethanil plus calcium chloride applied 2 weeks prior to harvest to McIntosh and Empire apples in Ontario and to Gala and Jonagold apples in British Columbia significantly reduced postharvest decay by Penicillium expansum (blue mold) and Botrytis cinerea (gray mold). However, decay control in McIntosh and Empire diminished after 8 to 12 weeks in 0 or 1 °C storage [ON, BC]. In a 2-year study, postharvest treatment of McIntosh and Empire apples with the biocontrol agent Pseudomonas syringae in combination with DPA gave effective control of blue mold and gray mold for up to 168 days in CA cold storage [ON]. CIPRA, a computer program to predict the risk of susceptibility of apples to storage disorders, was evaluated for the 4th year in Ontario. Low-temperature disorders develop in storage following cool and wet conditions during the months of July and August. CIPRA involves a risk model developed on the basis of weather data obtained during those months. CIPRA accurately predicted that due to the warm, dry season in 2005, apples were essentially risk free [ON]. Spraying Golden Delicious and Gala apples with a 1% emulsion of soybean oil 3 or 21 days prior to harvest reduced weight loss during up to 180 days of air or CA storage at 0.5 °C. In Golden Delicious fruit, weight loss was correlated with development of cuticular cracks, the occurrence and severity of which were reduced by preharvest soybean oil treatment. Late-season application of soybean oil on Golden Delicious and Fuji apples was not phytotoxic, did not alter fruit finish, and had beneficial effects postharvest, including reduced weight loss, increased aroma volatile production, better retention of flavor impact alcohols during prolonged CA storage, and improved flavor regeneration capacity after storage [WA]. Objective 3: 1-MCP sorption by non-target materials in storage rooms was evaluated. Items containing cellulose, e.g. wooden crates and cardboard boxes, absorbed significant quantities of 1-MCP, especially when damp. This might compromise the efficacy of 1-MCP treatment of fruits [MI]. The capacity of fruit tissues to absorb 1-MCP was measured. All fruits (including apple, melon, lime, tangerine, mango, and plantain) absorbed 1-MCP, but the rate of sorption differed markedly. Sorption rate was associated with insoluble dry matter content [MI]. The best 1-MCP treatment for extending yellow-life of bananas at ripeness stages 3.0 to 3.5 was exposure to 50 ppb for 20 h at 14 ºC. [CA]. Fruit of different tomato cultivars from several commercial growers responded similarly to 1-MCP treatment during postharvest ripening at 22 °C. Thus, cultivar and growing conditions may not affect the efficacy of 1-MCP. Tomatoes treated with <300 ppb 1-MCP exhibited normal color changes, while those treated with >600 ppb exhibited abnormal blotchy ripening and were unmarketable. 1-MCP treatment often caused an unexpected increase in the rates of ethylene and CO2 production. Ripening tomatoes treated at a maturity between breaker and turning did not respond well to 1-MCP [ON]. 1-MCP treatment (1 ppm 24 h at 0 °C) reduced production of CO2, ethylene, and aroma volatiles in Shiro yellow plums from the first but not from the second harvest. No effects were noted on ripening and quality parameters of Redhaven peaches. 1-MCP-treated plums and Fantasia nectarines were firmer than those not treated and this effect was more pronounced in fruit from the second harvest held for 2 weeks at 0 °C. 1-MCP-treated plums retained green color longer and turned yellow more slowly than control fruit. In contrast with 2004, there were no effects of 1-MCP treatment of nectarines on respiration, production of ethylene and aroma volatiles, soluble solids concentration, and color [ON]. 1-MCP (300 ppb) significantly delayed or prevented post-storage CO2, ethylene, and aroma volatile production in Bartlett pears, whereas ReTain reduced aroma volatiles only. Both treatments slowed the rates of softening and color change from green to yellow. After 4.5 months in air at 0 °C, most of the untreated pears had severe senescent scald and/or storage rot, whereas pears treated with 1-MCP were still of acceptable quality. Effects of 1-MCP on Bosc pears were similar to those on Bartlett but not as long lasting. Preconditioning at 10 °C for 5 or 10 days was of no benefit to post-storage quality of either Bartlett or Bosc pears [ON]. Effects of 1-MCP treatment (0.8-1.0 ppm, 24 h) on quality of Empire and Delicious apples in commercial controlled atmosphere (CA) or air storage were assessed. Internal ethylene concentration and post-storage softening were decreased by 1-MCP treatment. 1-MCP treated apples stored in air, but not those stored in CA, had higher soluble solids concentration. 1-MCP decreased the incidence of core browning in air- and CA-stored Empire fruit, but increased the incidence in CA-stored Delicious. There was no effect of 1-MCP on the incidence of internal browning and storage rots, which developed in both cultivars [ON]. For McIntosh, Empire, and Delicious apples at harvest and after 3 and 6 months of cold storage, production rates of CO2, ethylene and volatiles, as well as increases of internal ethylene and decreases in firmness were inhibited or delayed by a sprayable 1-MCP treatment (250 ppm) applied in the orchard 1 week prior to harvest. These effects were comparable to those of postharvest 1-MCP treatment (1 ppm). McIntosh treated with sprayable 1-MCP exhibited 100% incidence of skin damage at harvest, which intensified during storage as flesh tissue under the lesion became sunken. Fruit treated with adjuvant only or postharvest 1-MCP had no skin damage. Damage was halo-like, centered around lenticels, and most severe near the calyx. No skin damage was observed in Empire or Delicious at harvest; a few lesions developed during storage in Empire [ON]. Impact of 1-MCP on synthesis and retention of flavonoids during storage and ripening of Delicious apples was investigated. Anthocyanins, flavonols, flavan-3-ols and chlorogenic acid in peel tissue from fruit of 3 harvest maturities were quantified after a 120-day storage and 1-week shelf-life period. All compounds analyzed increased with advancing harvest date. Anthocyanins generally declined after storage, while chlorogenic acid levels increased. 1-MCP treatment resulted in retention of anthocyanins in the latter stages of storage, but did not affect flavonols and flavan-3-ols. Chlorogenic acid biosynthesis was inhibited in less mature 1-MCP-treated fruit during storage and shelf life. 1-MCP may inhibit PAL activity in preclimacteric fruit, but it appears that little postharvest biosynthesis of flavonoids occurs in apples, and 1-MCP treatment may maintain flavonoid levels of Delicious apples when applied at the proper harvest maturity [ON]. Scald control was evaluated in Cortland apples stored in 1% O2 for 2 months and in 2.5% O2 thereafter, alone and in combination with 1-MCP treatment. Air-stored control fruit had a scald incidence of 76% after 4 months and 100% after 7 months. Low O2 plus 1-MCP completely prevented scald after 4 months and reduced scald incidence to 11% after 7 months. 1-MCP treatment alone was more effective than low O2 CA [ME]. Increased risk of external carbon dioxide injury in apples treated with 1-MCP can be prevented by diphenylamine (DPA) application. 1-MCP does not increase the period of risk during CA storage, but it does prevent the decrease in susceptibility to injury that occurs if fruit are kept in air before CA storage [NY-I]. Increasing apple fruit maturity is generally associated with decreasing effectiveness of 1-MCP, but there is no internal ethylene concentration index available to the industry to determine if fruit should be treated with 1-MCP prior to storage. Fruit were grouped according to IEC values at harvest, treated with 1-MCP, and IECs of these fruit were followed during air storage. The responses varied greatly by apple cultivar [NY-I]. 1-MCP is less effective than DPA for scald control in most instances, but this varies by apple cultivar. The key event is recovery of fruit from inhibition of ethylene perception and production [NY-I]. Multiple low-dose (50 ppb) 1-MCP treatments combined with preconditioning at 10 °C for 5 days enabled normal ripening of Anjou pears, but scald development was unacceptable after 6 months of RA storage or 8 months of CA storage. Treatment with 25 ppb 1-MCP at harvest plus a subsequent treatment with 1000 ppm ethoxyquin after 1, 7, 30 or 60 days at -1 °C controlled scald without irreversible inhibition of ripening [OR-HR]. 1-MCP treatment (1 ppm) did not alter the efficacy of control of decay caused by Penicillium expansum (blue mold) and Botrytis cinerea (gray mold) in Empire and McIntosh apples treated with the fungicides PenBotec, Scholar, or Vangard and stored up to 120 days in air at 0 °C [ON]. Objective 4: Organic kiwifruits had higher concentrations of minerals, ascorbic acid, and total phenolic compounds (higher antioxidant activity) than conventional kiwifruits; there were no differences in concentrations of sugars and organic acids [CA]. Daily consumption of Bing sweet cherries for several weeks selectively lowered the circulating concentrations of three markers of inflammation in healthy men and women. Such anti-inflammatory effects may be beneficial for the management and prevention of inflammatory diseases [CA]. The effects of temperature and relative humidity on storage quality of strawberries, from both physical and nutritional aspects, are being investigated. The results highlight the inherent conflict between postharvest treatments that maintain quality attributes based on appearance and antioxidant components [NY-I]. The effects of 1-MCP on antioxidant composition, antioxidative capacity and anti-proliferation activity of apple extracts is under investigation [NY-I]. Sweet cherries sprayed with a 2% formulation of hexanal 1 or 2 weeks prior to harvest and then exposed to 1-MCP (1 ppm) prior to storage had phenolics levels 65% higher than those in unsprayed, untreated control fruit after 30 days in air at 5 °C. Muscadine grape varieties were compared for total anthocyanins and phenolics. Fruit source (grower and location) affected total anthocyanins, while total phenolics and ferric-reducing antioxidant potential were similar within a variety, regardless of source. Bronze muscadines had little anthocyanin, whereas bronze and purple grapes were similar in total phenolic content [USDA-OK]. European elderberries (Sambucus nigra) have long been used in medicine and their antioxidant properties have been extensively researched, whereas North American elderberry (S. canadensis) has had little attention. Elderberries grown in Missouri and Oregon were evaluated for phenylpropanoids and antioxidant potential. Total phenolics, anthocyanins, and ferric-reducing antioxidant potential (FRAP) were most consistent among sources for Adams 2, Brush Hill 1, and Gordon E selections, while Johns and Netzer were widely variable among sources and even among fruit samples. Generally, total anthocyanin and phenolic contents were similar to those of blackberry and blueberry [USDA-OK]. Citrulline, an amino acid used in the nitric oxide system in humans and highly effective in vasodilation, was first found naturally in watermelon. The effects of fruit variety, genotype, ripeness, flesh color, and tissue on citrulline level were determined. Flesh tissue had the highest concentration; genotype, flesh color, and ripeness had little effect on citrulline level [USDA-OK]. Watermelon flesh contains arginine, ornithine, and citrulline, amino acids thought to promote cardiovascular health. In plasma from a human clinical trial where subjects ingested 3 or 6 cups of watermelon juice per day for 3 weeks, it was found that arginine levels were slightly elevated, but there was no increase in plasma antioxidant activity [USDA-OK]. Fruit from a few genetic lines of the cultivated eggplant species Solanum melongena were found to have high concentrations of compounds in which caffeic and/or dihydrocaffeic acid are amide linked with spermidine, whereas fruit from the wild species S. incanum included the analogous series of spermine conjugates. These hydroxycinnamic acid amides of polyamines are potent antioxidants and are also of pharmacological interest. Some are known to be hypotensive compounds and/or have antimicrobial activity against parasitic protozoans. A prototype firmness tester was developed that was able to detect a bioyield point for apple fruit. Bioyield firmness exhibited a high correlation (r2 = 0.66) with Magness-Taylor probe texture measurements. The bioyield tester imparts a small, superficial bruise that does not degrade apple fruit and will be useful for measuring and monitoring fruit firmness non-destructively during growth, harvest, and postharvest operations [MI]. Objective 5: 1-MCP enhanced decay susceptibility of pear fruit wound-inoculated with Botrytis cinerea at harvest but had no effect on fruit inoculated after cold storage. Decay resistance in newly harvested pear fruit appears to involve the ethylene wound response pathway. No correlation between fruit softening and susceptibility to B. cinerea was observed. However, polygalacturonase deficient Bcpg1 mutants of B. cinerea are less virulent than the wild type strain, indicating that pectin catabolism plays a role in susceptibility of pears to decay by B. cinerea [OR-C]. Suppression of PGIP expression in tomato fruit leads to enhanced susceptibility to decay by B. cinerea. The identification of a second PGIP-encoding sequence in tomato suggests that a PGIP gene family may include members that have different expression patterns in response to developmental and environmental cues [CA]. Resistance to B. cinerea decay was compared in ethylene-deficient transgenic (constitutive ACS over-expression) and wild type Greensleeves apple fruit. Transgenic fruit with very low ethylene levels were more susceptible to decay than untransformed apples [OR-C, CA]. Work was begun to identify ethylene response factor (ERF) genes specifically induced during interactions of pome fruits with B. cinerea. RNA from control fruit or apples treated with ethylene or inoculated with B. cinerea was used with degenerate primers to amplify the DNA-binding domains of apple ERF mRNAs. Putative ERF genes representing three subfamilies were then cloned [OR-C]. Studies of ripening-related cell wall metabolism in small berry fruits have identified similar patterns of wall disassembly in boysenberries and raspberries and a distinctly different pattern for blueberries [CA]. Accumulation of mRNAs encoding cell-wall modifying enzymes in Macoun and Honeycrisp apple fruit during 4 months of 0 °C storage were measured using real-time PCR. Expansin3 (EXP3) transcript increased substantially in Macoun fruit but was not detected in Honeycrisp fruit at harvest or after storage, suggesting that crispness of the latter cultivar may be related to a lack of expansin in mature fruit [MN]. A microarray for gene expression analysis of ripening apple was constructed with approximately 200 known and 10,000 unknown gene products. Expression analysis revealed approximately 700 gene products to be of interest and these were sequenced. One gene putatively codes for an aminotransferase, which in yeasts is required for production of branched-chain esters. A second gene putatively encodes a decarboxylase that could serve to degrade products of the transaminase reaction [MI]. Studies of transgenic lines of rin tomatoes have shown surprising interactions of PG and Expansin during ripening-related cell wall metabolism and demonstrated that the combined action of these two wall-modifying proteins can cause substantial fruit softening [CA]. Tomato plants were transformed with RNAi constructs of two phospholipase D genes, LePLDa2 and LePLDa3, driven by the CaMV 35S promoter. Vegetative growth, flowering, and fruit set of most of the transgenic lines were normal, whereas several T0 LePLDa2 RNAi transformants exhibited a reduced rate of fruit ripening on the plant. These lines will be propagated and their fruit will be tested for LePLDa2 and LePLDa3 expression, PLDa enzyme activity, and postharvest rates of ripening and senescence [USDA-MD]. A second full-length phospholipase Da cDNA, CmPLDa2, was cloned from Honey Brew hydbrid honeydew melon. The nucleotide and encoded amino acid sequences of CmPLDa2 are, respectively, 75% and 78% identical to those of previously cloned CmPLDa1. Work is in progress to compare the relative expression of CmPLDa1 and CmPLDa2 in mesocarp tissues during development, ripening, and senescence of honeydew melons [USDA-MD]. Effects of 1-MCP on ethylene and polyamine metabolism and associated gene expression during ripening of tomato fruit were investigated. Polyamines do not appear to be directly associated with the delay in tomato fruit ripening induced by 1-MCP but may prolong the fully ripe stage before the fruit senesce [NY-I]. Fruit of the tomato cultivar Delayed Fruit Deterioration (DFD) exhibit minimal softening but undergo otherwise normal ripening, unlike all other known non-softening tomato mutants. Cell wall degradation, reduced cell adhesion, and expression of genes associated with cell wall metabolism were the same in DFD as in normal fruit. However, ripening DFD fruit showed minimal water loss and elevated cellular turgor. Biochemical and biomechanical analyses identified unusual features of DFD cuticles, suggesting that changes in cuticle composition and architecture are an integral and regulated part of the ripening program [NY-I]. The relationship between gamma-aminobutyric acid (GABA) synthesis and postharvest stresses [controlled atmosphere (CA) and chilling temperatures] was studied. An increase in GABA concentration during CA storage of Empire apples was dependent on CO2 concentrations, enhanced by 1-MCP, and inhibited by DPA. GABA was detected in Northeast strawberries only when fruit were placed in elevated CO2 storage conditions. Tomato fruit of L. pennellii introgression lines stored at 3 °C for 3 weeks had elevated GABA levels and the increase in GABA was greater in fruits from lines most susceptible to chilling injury [NY-I]. Transcript levels of key flavonoid biosynthetic (PAL and CHS) and ethylene perception (ERS1) genes in fruit peel tissue were determined during postharvest storage of control and 1-MCP-treated (1 ppm, 24 h) red and green Anjou pears. ERS1 expression was fairly constant during cold storage (0-1°C) and subsequent shelf life (10 days, 21 °C); 1-MCP treatment reduced ERS1 transcript substantially. PAL expression increased to high levels during shelf life of control fruit, but was strongly suppressed in 1-MCP-treated fruit. CHS mRNA was abundant at harvest and after removal from cold storage, but declined rapidly to undetectable levels during shelf life. 1-MCP treatment accelerated this post-storage decline in CHS transcript. The increase in PAL and decrease of CHS expression after removal from storage could divert carbon from flavonoid compounds into simple phenols [ON]. Effects of temperature, hypoxia, and 1-MCP treatment on ethylene production and scald development in Granny Smith apples were determined. An O2 concentration below 6-8% delayed onset of the ethylene climacteric, with associated suppression of ACS1 but not ACO1. Apples ripened faster at 10 °C, yet the climacteric rise in ethylene occurred 15 days earlier in fruit held at 1 °C. 1-MCP (1 ppm) plus 1.5% O2 CA suppressed ACS1 and ERS1 expression, inhibited ethylene production, and extended storage life of apples held at 6.5 °C or 10 °C. 1-MCP and/or 1.25 % O2 CA suppressed onset of the ethylene climacteric and prevented scald for 9 months, however, transfer of these fruit to air at 18 °C promoted ethylene production. In Granny Smith and Red Delicious apples, alpha-farnesene synthesis was critically dependent on ethylene production [MD]. Two 2.0-kb genomic DNA fragments representing two distinct promoters of the alpha-farnesene synthase gene AFS1 were cloned from Law Rome apple. Putative ethylene and low temperature response elements found in these promoters may be responsible for the ethylene-dependent up-regulation of AFS1 expression during the first few weeks of cold storage, which results in accumulation of a-farnesene in peel tissue of the stored fruit [USDA-MD]. An apple glutathione peroxidase cDNA (MdGPX) was cloned using RNA from peel tissue of Law Rome apples. MdGPX was expressed at moderately high levels in peel tissue of Law Rome apples throughout 6 months of 0.5 °C storage in air. Expression increased with storage duration and was reduced in fruit treated with 1 ppm 1-MCP prior to storage. GPX can catalyze the reduction of alkyl hydroperoxides to the corresponding alcohols; thus, MdGPX activity may result in accumulation of conjugated trienol oxidation products of alpha-farnesene in apple skin during cold storage [USDA-MD]. In Granny Smith apples treated prestorage with diphenylamine (DPA) or DPA plus 1-MCP to control superficial scald, DPA derivatives resulting from C-nitration, C-hydroxylation, O-methylation, and N-nitrosation accumulated during storage. Poststorage ripening, 1-MCP treatment, and CA storage had varied effects on DPA derivative contents, which suggested that reactive oxygen and nitrogen species such as *OH, *NO, and *NO2, or enzyme-catalyzed reactions, may be present or occur during certain ripening and senescence-related processes. However, correlations between superficial scald incidence and contents of specific DPA derivatives were not observed [WA, USDA-WA]. A simple field test to determine optimal apple fruit harvest maturity was assessed. The test is based on the observation that a small wound on the surface of a preclimacteric apple fruit stimulates development of a red halo, which subsequently disappears with the advent of climacteric ripening or will not develop at all if a fruit is producing system-2 ethylene [WA].