ASHS 2025 Conference

Muscadine grapes are native to the southeastern U.S. and are known for their unique flavor and aroma. Rapid postharvest deterioration of muscadine berries is a major barrier in market expansion. This study investigated the change in muscadine berries’ general composition over a four-week storage period. The vines were planted at the Chilton Research and Extension Center, Clanton, AL in a randomized complete block design with four single plant replications. Berries from the perfect-flowered cultivars ‘Hall’, ‘Paulk’, and ‘Southern Home’, and from the pistillate cultivars ‘Eudora’ and ‘Supreme’ (standard) were studied. Experimental vines were harvested on Aug. 2 and Sept. 4, 2024. One-pound clamshells were filled with berries collected from each experimental vine. Fresh samples (Week 0) were compared for berry quality changes occurring after 1, 3, and 4 weeks of cold storage at 4°C and 85% RH. After completing each storage period exposure, the berry samples were allowed to rest for 1 hour at room temperature. The change in berry weight and firmness was recorded after each storage treatment and 5 berry subsample was frozen at -80°C for later analysis of total soluble solids (TSS), titratable acidity (TA), TSS:TA ratio and pH. Our results indicate that the 4 Weeks storage period led to a significant weight loss of 11.3% in ‘Paulk’ and 7.6% in ‘Supreme’ berries in comparison to Week 0. It was found out that both cultivar and storage duration were accountable for the significant firmness reduction with ‘Paulk’ and ‘Supreme’ experiencing 51.4% and 46.2% reduction by Week 4 in storage. Titratable acidity increased significantly over time in all cultivars. The highest TA at Week 4 (0.67) was recorded for ‘Southern Home’, while ‘Paulk’ berries had the lowest TA (0.44), indicating strong cultivar effect (p < 0.0001). After the first week of storage, berries of ‘Hall’ were significantly sweeter than ‘Paulk’, while at Week 4, all cultivars had similar sweetness. Due to an increasing acidity trend, fruit pH decreased with increase in storage time exposure. Both cultivar and storage duration affected the berry pH. TSS:TA ratios varied significantly by cultivar and storage period duration with ‘Supreme’ maintaining its sweetness level throughout the four weeks of storage. Overall, the prolonged storage period resulted in significant firmness reduction and increased acidity with ‘Paulk’ exhibiting the highest reduction of berry firmness while ‘Supreme’ consistently maintained sweetness level over the 4-week period.

Brassica leafy greens are important vegetable crops in the Southern United States, where they are commercialized in whole and fresh-cut formats. Their consumption is associated with health benefits as these crops are rich in bioactive compounds with antioxidant activity. Several factors contribute to the postharvest quality of Brassica leafy greens. Preharvest seasonal variations associated with environmental variables can have a significant influence on shelf-life and quality maintenance and have been reported in various Brassica species. The effect of postharvest temperature management and mechanical stress induced by fresh-cut processing has also proven to be critical in organoleptic and nutritional quality; however, none of these factors have been systematically studied in collards, kale and turnip greens. This project aimed to address this knowledge gap by investigating the postharvest performance of whole and fresh-cut kale, turnip greens and collards during storage at different temperatures (2, 5 and 7°C) for up to 28 days in two growing seasons (fall and winter-spring). Cooling delays after harvest were imposed on some experiments. We also characterized the shelf-life of commercial and traditional collards ('landraces') commonly grown in the Southeast. Organoleptic (color, marketability scores, total soluble solids) and compositional (total chlorophyll, carotenoids, total polyphenols, lycopene, vitamin C and ammonia contents) were monitored during postharvest storage. Results revealed there was significant quality variation in fresh-cut kale, collards and turnip greens, which could attributed to genotypic differences and preharvest factors in each growing season. High shelf-life variability among commercial collards and landraces was observed. Moreover, postharvest storage at abusive temperatures accelerated quality deterioration in fresh-cut collards to a greater extent than in whole leaves. Collectively, these findings highlight that adjusting postharvest practices to seasonal shelf-life variations can contribute to minimizing food losses and optimizing produce supply chain performance. Furthermore, postharvest temperature regimes are critical in influencing the visual quality and nutrient retention of whole and fresh-cut collards during storage.

Florida ranks third in the United States for lettuce production with approximately 90% of commercial lettuce cultivated on organic soils in southern Florida. These organic soils require phosphorus (P) inputs to sustain economic production and ensure lettuce shelf-life. Lettuce shelf-life depends on quality factors such as firmness, appearance, color, texture, decay, discoloration, and wilting. Optimal P fertilizer management is necessary to improve yield, market quality, and ensure postharvest quality (shelf-life). Over-fertilization can reduce quality, while deficiencies can limit yield and shelf life. Therefore, the objective of this research was to understand how different rates of P affect the lettuce shelf-life across four cultivated morphological types. Two field trials were conducted at the Everglades Research and Education Center in Belle Glade, FL, during the lettuce growing seasons (spring, fall, and winter). Experiments were set as a split-plot designed in which P fertilizer rates (0, 48, 97, 150, 195, and 210 lbs P2O5 acre-1) were considered as the main plot and four lettuce types (romaine, iceberg, butterhead, and leaf) as the subplot. Ammonium polyphosphate (11-37-0) was used as the source of P fertilizer. Shelf-life was evaluated over 10 days at 15 °C and 90% RH using visual ratings of 9 (excellent) to 1 (poor) following the protocol for an accelerated shelf-life testing. The estimated shelf-life was considered as the number of days when lettuce reached an acceptable appearance on the rating scale of ≥5 and multiplied by a factor of 2 (2-fold factor proportional to the deterioration rate). The results indicate varying responses to P fertilizer application in shelf-life that were significantly morphological-type dependent. Overall, leaf lettuce had the shortest shelf-life and iceberg lettuce had the longest shelf-life. Butterhead had an acceptable estimated shelf-life rating of 5 at 24 days at 210 lbs. P2O5 acre-1 while romaine and leaf had a shelf-life rating of 5 at 22 and 21 days at 210 lbs. P2O5 acre-1, respectively. In addition, crisphead had an acceptable estimated shelf-life rating of 5 above 35 days at 150 lbs. P2O5 acre-1. However, an acceptable shelf-life was maintained at 48, 150, or 195 lbs. P2O5 acre-1 in iceberg lettuce over 30 days. Together these results demonstrate that there is no effect of increasing the rate of P2O5 acre-1 to maintain economic yields on the lettuce shelf-life. Rather, shelf-life quality increases with P inputs.

The incidence of necrotic peel disorders during cold storage is a severe CI symptom observed in hardy kiwifruit, impacting fruit visual quality. This study focuses on understanding the mechanisms of necrotic peel disorder in ‘Daebo’ hardy kiwifruit cultivar during cold storage. This research aimed to investigate the effects of different soluble solids content (SSC)-based fruit maturity at harvest on the severity of peel disorder after storage and to present the associated biochemical alteration using integrated transcriptomic, antioxidant, and lipidomic analyses. The fruit of ‘Daebo’ hardy kiwifruit cultivar harvested at various SSC levels, including 5.5%, 6.1%, and 7.2%, were cold-stored for upto four weeks. Fruit harvested at 5.5% SSC exhibited the highest severity of necrotic peel disorder, accompanied by significant weight loss and elevated reactive oxygen species (ROS) levels. The enhanced activities of antioxidant scavenging enzymes, such as superoxide dismutase and ascorbate peroxidase, were observed, indicating the response of fruit to oxidative stress. However, lower enzymatic activities of dehydroascorbate reductase and glutathione reductase were insufficient to restore the ascorbic acid-glutathione cycle. In contrast, the 7.2% SSC fruit contained higher concentrations of phenolic compounds, suggesting their role as natural antioxidants in mitigating oxidative damage. Additionally, lipid analysis revealed increased levels of phosphatidylcholine and fatty acids during fruit maturation, which are crucial for membrane stability. Notably, the differences in phosphatidic acid concentrations between SSC levels indicated its potential role in ROS scavenging. Overall, this study elucidates the biochemical mechanisms contributing to necrotic peel disorder in hardy kiwifruit during cold storage, highlighting the importance of SSC at harvest in managing fruit quality. These findings can comprehensively understand necrotic peel disorder and fruit maturity in hardy kiwifruit.

Postharvest longevity of perishable produce remains a challenge in the global fresh market supply chain. Postharvest longevity is determined by the rates of ripening and senescence, which are influenced by harvest time and storage conditions. Ripening and senescence are predominantly regulated by ethylene, which produces a plethora of metabolic effects within the harvested produce, leading to physiological and developmental changes during postharvest. Broccoli (Brassica oleracea L. var. italica) are prone to yellowing and wilting due to the relatively high respiration rate and tissue senescence during postharvest handling, transportation, and storage, which greatly affects the quality and reduces market value that led to the problem of food waste and loss. Broccoli florets treated with hydrocooling, 1-MCP (ethylene inhibitor) and controlled atmosphere (CA) can delay the senescence. However, little is known about the mechanisms on how those treatments worked at the molecular level. Here, we combined a physiological, biochemical, and genomics analyses on the postharvest broccoli and identified a core gene regulatory network governing senescence-associated developmental events, ethylene-regulated signaling pathways, and activation of stress responses. Additionally, we developed genome-editing toolkits by CRISPR/Cas9 system to understand deterioration of broccoli as well as through machine learning approaches to aid development of an innovative and easy-to-use accessibility tool to accurately estimate the freshness of produce. The findings give insights into ethylene biosynthesis and signal transduction at the tissue-specific level in broccoli and provide guidance on how to extend broccoli shelf life and reduce its economic losses, which also generate genetics and molecular recourses for marker-assistant breeding and expand the general scientific knowledge of regulating senescence of Brassicaceae family.

Most of the world's pistachios are grown in saline-sodic soils with soil boron (B) levels over the 2 ppm suggested for most trees. As a resulting symmetrical leaf edge necrosis produced by B accumulation, “B toxicity”, is common and regarded as damaging to leaf photosynthetic capacity. This study was carried out in a 8-year-old pistachio orchard with field-budded Pistacia vera cv. ‘Golden Hills’ on cloned P. atlantica x P. integerrima, UCBI rootstocks, spaced at 18 x 20 feet, 121 trees per acre. The soil was a silty clay loam saline-sodic Cerrini complex with salinity ranging from 3 to 15dS/m, pH 7.5 to 8.2, boron levels of 3 to 12 ppm and soil sodium levels ranging from 16 to 130 meq/l (370 to 3000 ppm). High soil and water B levels will produce increasingly higher scion leaflet B leaf symptoms ranging from a slender marginal necrosis to almost complete necrosis. We analyzed the relationships among soil B, leaf B, percentage of damaged leaf surface and marketable yield. Our results a demonstrated a strong negative correlation of yield as a function of soil B. As soil B levels increased yield decreased; r = - 0.705, p < 0.001. However, both leaf B levels and % leaf damage had had weak, insignificant relationships with soil B levels. As soil B increased leaf B levels and the percentage of damaged leaf areas did not increase. However, there was a moderately positive relationship between leaf boron levels and leaf damage; r = 0.50, P

Short-day onions such as Vidalia are vital in warmer climates, but their delicate skins make them prone to an average of 8% bruise damage during mechanical harvesting. As a result, manual hand harvesting remains the preferred method despite its high cost of $3,951/hectare for labor, according to the 2019 Onion Irrigated Budget (University of Georgia). Addressing issues of mechanical harvesting could offer a more cost-effective alternative while solving the labor shortage problem. This study aimed to evaluate the bruise tolerance of five Vidalia varieties (Vidora, Sweet Magnolia, Sapelo, Red Maiden, and Monjablanca) under different impact conditions and identify the specific sections of mechanical harvesters that contribute to bruising. Identifying the most bruise-tolerant varieties can guide growers in selecting onions better suited for mechanical harvesting, reducing labor costs and postharvest losses and by understanding which sections of the harvester cause the most damage, modifications can be made to reduce bruising. Controlled pendulum tests were conducted to simulate onion-to-surface impacts, using onions embedded with Impact Recording Devices (IRDs) to measure impact forces at two maturity stages (80% tops down and one week after 80% tops down) and two drying durations (0 and 7 days). Drop heights were selected based on bruise damage results for Vidora, with two levels for each surface type: 10 cm and 30 cm for flat surfaces, and 30 cm and 55 cm for padded surfaces. A total of 320 impacts were recorded. To identify the most bruise-prone sections of the harvester, 23 field trials were conducted using a Top Air Harvester, with IRDs embedded within onions and placed on field, to capture real-time impact data. The Top Air Harvester, consisting of a collecting belt, elevator, sorting belt, and conveyor, transferred onions to the bulb collection truck within 36 seconds. Early results for Vidora variety indicate that bruising severity increases with higher drop heights, on flat surfaces, while padded surfaces significantly reduce damage. Testing all five varieties will provide a comprehensive profile of bruise tolerance, helping growers select varieties better suited for mechanical harvesting, potentially reducing labor costs. Initial analysis of field trials revealed that the conveyor-to-bin transition generated the highest impact forces, significantly contributing to bruising. These preliminary results indicate the need for design improvements in this section to reduce impact damage and enhance mechanical harvesting efficiency. Further testing will validate these findings and guide the development of improved mechanical harvesting practices.

Alternative Oxidase Interacts with SNF1 Kinase to Modulate Energy Metabolism During Pear Fruit Ripening Adwaita Prasad Parida and Amit Dhingra1 Correspondence: Amit Dhingra, Professor, Department of horticultural sciences, A

Pawpaw (Asimina triloba), a North American tree fruit, belongs to the Annonaceae family and is the only temperate member of this family. Pawpaw is emerging as an alternative high-value niche crop for small farms in Kentucky and surrounding states; however, due to its highly perishable nature, the marketing window for fresh fruit is currently limited. Pawpaw fruit can only be stored for 3-5 days at room temperature or for about 1 month under cold storage at 4 °C. The objective of this study was to examine the efficiency of modified atmosphere with plastic packaging in cold storage to increase the shelf-life of pawpaw fruit and its impact on the quality attributes of fruit. This experiment was conducted with fruit from the pawpaw cultivar Sunflower. Fruits were harvested and stored in three treatments of modified atmosphere in 2.5-gallon plastic container bags, with the treatments of 1) plastic bag with ambient air (Control), 2) plastic bag with an additional ethylene absorber, and 3) plastic bag with modified atmosphere of low oxygen and high carbon dioxide gas mix (12% O2 and 10% CO2 and balance nitrogen). There were three replicate bags per treatment with each bag containing three fruits. Fruits were stored at 6 °C. Data on gas composition in bags and quality parameters of fruit such as firmness, brix, color (L*, a*, b*), and weight were taken on 5, 10, 20, 40, and 80 days of storage. The ethylene absorber and gas mix treatments maintained lower ethylene concentrations inside the bags as compared to the control. The gas mix treatment resulted in reduced fruit weight loss and maintained the lightness of fruit pulp significantly. However, firmness in all fruits significantly declined after 20 days of storage in all treatments. These data suggest that the ethylene absorber and gas mix treatments during cold storage have at least some potential for extending shelf-life of pawpaw, with additional modifications or harvest times.

Several apple cultivars are susceptible to lenticel breakdown including but not limited to ‘Honeycrisp’, ‘Red Delicious’, ‘Gala’, and ‘SweeTango’. ‘Honeycrisp’ in particular has received considerable scrutiny by apple growers and packers due to its low percentage of packable fruit. ‘Honeycrisp’ in Michigan are put into storage with little to no disorders and, in 3-5 months, are pulled out of storage achieving less than 50% pack-outs of quality fruit in severe cases. These low pack-outs are a result of internal disorders, a physiological disorder ‘bitter pit’, lenticel breakdown, advanced decay, and some unknown light brown spotting that can be similar or smaller in size than lenticels. Investigations into the mechanisms behind these various ‘spots’ and discriminating between them is an essential first step in understanding the disorders and the discovery of solutions for growers and storage operators. In this study, three preliminary assessments were made to resolve the ambiguity behind lenticel breakdown and associated ‘spots’: 1) apple lenticels were imaged by light and scanning electron microscopy and characterized, 2) ‘Honeycrisp’ and ‘SweeTango’ apples were wrapped in paper and mesh bags on the tree as a field chemical spray exclusion assessment, and 3) a preliminary look at the microbiome of healthy and unhealthy lenticels. The latter effort revealed that ‘Alternaria’ species dominate the fungal community of unhealthy lenticels.

The interspecific pear cultivar ‘Greensis’ has become a highly demanded pear cultivar due to its unique flavor of sweetness, crispness and juiciness. This study evaluated the postharvest storage quality of ‘Greensis’ pear at two maturity levels, treated with the 1 µL L-1 1-methylcyclopropene (1-MCP), pre-storage conditioning (PSC), and the combination treatment of 1-MCP and PSC before long term cold storage at 0.5 °C for 6 months. Both the incidence and severity of physiological disorders, such as cortex and core browning, were significantly reduced in PSC treatments, meanwhile, the severity levels of cavity were notably lower in treated fruit compared to untreated (control) fruit. Among the targeted metabolites, soluble carbohydrates and organic acids particularly, sucrose and shikimic acid were lower in mature fruit than immature fruit. Moreover, the contents of glucose, fructose, malic acid and shikimic acids were higher in PSC treated fruit than the other treatments especially in mature fruit. The branched-chain amino acids, including isoleucine and leucine, glutamic acid and phenylalanine, in all treatments were lower in immature fruit, meanwhile, methionine was higher in mature fruit. Additionally, in immature fruit, the contents of asparagine, serine, threonine and proline in the combination treatment of 1-MCP and PSC were higher than the other treatments. In addition, the phenolic contents of all treated fruit were higher in immature than mature fruit especially in chlorogenic acid, arbutin, caffeic, p-coumaric acid, and gallic acid after long term cold storage. Overall, these results suggested that the higher accumulation of phenolic compounds and specific amino acid contents in immature fruit play as a defense mechanism and enhances cold stress tolerance during long-term cold storage. Furthermore, PSC treatments effectively maintain the postharvest fruit quality by reducing the physiological disorders in cold stored ‘Greensis’ pear.

Blackberry berries are highly perishable fruits, requiring effective postharvest management to maintain quality during storage. This study investigates the shelf-life and postharvest physiology of three blackberry cultivars ‘Ponca’, ‘Freedom’, and ‘Osage’—stored at 0°C for 0 to 7 days and 5°C for 8 to 16 days. Key parameters measured include red drupelet reversion, leakiness, weight loss, acidity (citric, malic, tartaric acid), pH, Brix content, anthocyanin, and antioxidant content. Fresh blackberry fruits of three different cultivars were collected from a commercial garden and stored in 6 oz clamshell boxes under controlled conditions. Physiological parameters such as weight loss, red drupelet reversion, and leakiness were evaluated at 0, 7, 12, and 16 days of storage. For chemical analysis, an additional 6 oz clamshell box for every sample was stored at -40°C at 0, 7, 12, and 16 days to assess acidity, Brix content, anthocyanin, and antioxidant. Results indicate significant varietal differences in postharvest stability. ‘Freedom’ exhibited the highest red drupelet reversion and leakiness, with a steady decline in acidity over time, suggesting rapid deterioration. ‘Osage’ maintained the most stable postharvest quality, showing the lowest red drupelet reversion and highest acidity, which may contribute to improved storage potential. ‘Ponca’ demonstrated moderate stability but exhibited a sharp increase in leakiness and red drupelet reversion at later stages, indicating postharvest instability. Weight loss data revealed that ‘Freedom’ experienced the highest weight reduction, while ‘Ponca’ and ‘Osage’ exhibited greater stability over the storage period. Acidity levels varied significantly among cultivars, with ‘Osage’ retaining the greatest citric, malic, and tartaric acid concentrations, potentially enhancing shelf stability. ‘Freedom’ exhibited the lowest acidity, affecting taste and preservation. pH trends revealed that ‘Freedom’ lost acidity fastest, while ‘Ponca’ maintained stable acidity, making it more suitable for extended storage. These findings highlight the need for cultivar-specific postharvest strategies. While ‘Osage’ appears to have better natural postharvest qualities, ‘Ponca’ and ‘Freedom’ may require optimized storage conditions to minimize quality loss. This study provides valuable insights for improving blackberry storage, reducing postharvest losses, and extending marketability.

Reduced fruit quality throughout cold storage is a major stakeholder-identified factor limiting production and marketability of the profitable apple ‘Honeycrisp’ in the Mid-Atlantic. ‘Honeycrisp’ is known to be a chilling sensitive cultivar when cooled immediately after harvest, therefore fruits are submitted to a postharvest conditioning treatment (10ºC for 7 days) prior to cold storage (3ºC). However, conditioning exacerbates the expression of bitter pit, rendering the fruit unmarketable. Moreover, maturity at harvest is a critical factor affecting apple fruit quality as well as susceptibility to chilling stress. Ethylene, the primary hormone related to hastening fruit maturity, can be regulated via the use of preharvest ethylene regulators. We aimed to characterize and compare the effects of different preharvest ethylene regulators on ‘Honeycrisp’ fruit maturity, quality and chilling sensitivity during postharvest. Three preharvest ethylene regulators with different modes of action were applied based on manufacturer’s recommendations, including 1- methylcyclopropene (1-MCP, Harvista), aminoethoxyvinylglycine (AVG, Retain), Ethephon (Ethrel) and a control. Fruits were harvested at two maturity stages: at the anticipated commercial harvest (CH) and one week after CH (CH 1). After harvest, in each case, fruit were submitted to conditioning (10ºC for 7 days) and then stored at 3ºC. Fruit from all 8 treatments were evaluated at harvest, and after 8, 16 and 24 weeks of storage at 3ºC, followed by a shelf-life period (7 days at 20ºC). Our results show that preharvest ethylene regulator treatments impacted fruit maturity and quality of ‘Honeycrisp’ apples during storage. Ethylene production was reduced in 1-MCP and AVG treated fruit, with the latter showing the lowest values throughout storage during both harvest dates. Concurrently, 1-MCP and AVG treated fruits displayed a higher flesh firmness as well as a greener background color (as indicated by higher IAD values) compared to Ethephon- treated and control fruit. Skin blush was negatively affected by 1-MCP and AVG applications, which were maintained throughout postharvest, with AVG-treated fruit exhibiting the significantly lower values. Effects on starch pattern indices and soluble solids contents were inconsistent. Chilling sensitivity, through the presence of soft scald, was not observed, but 1-MCP treated fruit presented the highest bitter pit incidence, followed by AVG-treated fruit, while Ethephon and control fruit displayed the lowest. This study contributes to understand how preharvest ethylene modulation influences ‘Honeycrisp’ apple maturity and quality throughout storage.

Blackberry (Rubus spp.) production in Georgia is valued at $19.9 million annually with approximately 1,900 planted acres, mostly concentrated in the southern part of the state. Blackberries have been increasingly planted in Georgia as a dynamic alternative crop that can diversify and support blueberry growers’ income. The harvest season is short, starting in mid-May and ending mid-July. The planted genotypes are mainly from other Southeastern breeding programs often with little to no testing on their suitability for the local growing conditions. Four University of Arkansas-bred cultivars – ‘Caddo,’ ‘Osage,’ ‘Ouachita,’ and ‘Ponca,’ were selected with a goal to identify the most appropriate cultivar for production in Georgia climatic conditions. Blackberries were hand-harvested, field-packed, placed in cold storage for up to 21 days, and evaluated over a two-year harvest period from a commercial field in Holt, GA (31.5957˚N, 83.1507˚W). Red Drupelet Reversion (RDR) is a major postharvest disorder where fully ripe, black drupelets revert to red color after harvest. Assessments for RDR incidence were conducted immediately after harvest and every seven days, along with measurements of berry physicochemical traits. Consumers' taste panels were conducted a day after harvest. A high incidence of RDR was quantified at harvest and after storage for ‘Ouachita,’ followed by ‘Ponca,’ ‘Caddo’ and ‘Osage.’ In addition, the panelists favored ‘Caddo’ blackberries, while ‘Ouachita’ was the least preferred cultivar. Appropriate preharvest and postharvest practices, in combination with timely, gentle harvests should be employed to decrease RDR incidence and maintain fruit quality.

Edible nanoparticle coating materials were developed from sweetpotato peel tissue combined with sodium alginate and tested for their efficacy in reducing sweetpotato and potato postharvest deterioration. The bio-based nanoparticle coatings applied as thin films to the surface of sweetpotato roots and potato tubers reduced postharvest weight loss and respiration rate. The sweetpotato peel-based nanoparticle coating formulations included 1% and 2% sodium alginate. To enhance the structural integrity of the coatings, they were cross-linked by immersion in a 1% calcium chloride solution. The crosslinked formulations significantly outperformed non-crosslinked coatings and uncoated samples by minimizing weight loss (to below 2.0%–4.0% versus 3.5%–6.5% in controls) and decreasing respiration rates (to 5-13 mL CO₂/kg·h versus 7-20 mL CO₂/kg·h in controls) over extended storage periods. The enhanced performance is attributed to the formation of a dense, mechanically robust coating matrix. Sweetpotato peel tissue nanoparticles combined with sodium alginate and crosslinked with calcium chloride offer promise as sustainable coating materials for reducing fresh produce postharvest deterioration

Fresh grapefruit consumers are trained to expect vivid yellow-orange peel color, depending on the variety, even though peel color has little to do with internal maturity or quality. The greasy spot rind blotch disease has been in Florida for many years, ascribed to a fungal pathogen called Zasmidium citri-griseum (previously named Mycosphaerella citri). Besides causing defoliation, it also mars the peel with tiny black specks that cause the rind to remain green, even after degreening. The spots can coalesce into black patches in extreme cases, sometimes called “pink pitting” or greasy spot rind blotch. Growers had this disease under good management, but within the past five years, fruit with similar symptoms started appearing as early as November, when nighttime temperatures are low, and peel color should improve instead of regreening. The symptoms are like greasy spot rind blotch, but there are few to no symptoms on the leaves of the same trees. Thus, the industry generally refers to the disorder as “greasy green” until a more definitive identification of the causal agent and disease development is determined. In a 2021 grower survey, 89% of respondents experienced the disorder to some extent, with packers reporting losses ranging between $20,000 and $1.7 million. There was no consensus among growers and packers regarding the cause of greasy green or the factors contributing to the problem. While studies are underway to determine if the disorder is indeed related to greasy spot rind blotch, studies were initiated to determine if affected fruit could be degreened effectively, as many packers often ended up abandoning degreening attempts on affected fruit and not using them for the fresh market. Our tests found that even after degreening (5 ppm ethylene at 27oC) red and white grapefruit for up to 5 days, their peel color still was not acceptable (