ASHS 2025 Conference

Extreme heat events threaten raspberry (Rubus ideaus) production in the U.S. Pacific Northwest. The aim of this study was to evaluate strategies for reducing heat stress at a field site located in Prosser, Washington. Treatments were arranged in a split-plot design with four replicates and included three heat mitigation treatments (evaporative cooling with micro-sprinklers, shade cloth, and an untreated control) as main plots and four genotypes (‘Meeker’, ‘WakeField’, WSU 2188, and ORUS 4715-2) as subplots. Across the genotypes, evaporative cooling and shade cloth enhanced photosynthesis and chlorophyll fluorescence and increased yield compared to untreated controls. Shade cloth also resulted in higher stem water potentials than the other mitigation treatments, indicating improved hydration in each genotype. Preliminary economic analyses indicate that shade cloth is more expensive to install than micro-sprinklers for cooling and may interfere with mechanical operations. Evaporative cooling, on the other hand, increases weed pressure, which requires additional management. It also increased postharvest pathogens on the fruit after two weeks of cold storage in ORUS 4715-2. In each case, cooling was run continuously whenever ambient air temperature was > 30°C. Next, we will evaluate whether cooling for 15 minutes every hour is effective and results in fewer weeds and pathogens than continuous cooling.

The blackberry (Rubus spp.) industry in the Pacific Northwest (PNW) has rapidly expanded in recent years due to growers and major berry companies’ capacity to produce high-value fruit for fresh and processing markets. The expansion of the blackberry industry has been further supported by increases in fresh and frozen blackberry consumption. However, revenues and crop expansion in northwest Washington (WA) are limited by freeze events during the winter period that affect fruit production. Freezing temperatures below critical thresholds irreparably damage primary bud meristems. However, little is known about the conditions resulting in freeze damage, as well as the duration of dormancy and time to bud break among key blackberry cultivars. The objective of this study was to evaluate dormancy and cold hardiness of ‘Victoria’ and ‘Celestial’ blackberry floral buds in the PNW. Samples were collected weekly from 15 Oct 2024 to 7 March 2025 from two commercial farms in Skagit County, WA. Sampled laterals were cut into smaller cuttings, each containing one single floral bud, and subjected to either dormancy or cold hardiness evaluations. Samples for the dormancy evaluation were placed in suitable growing conditions (22 C°, 16 h light), and time to bud break was quantified. In parallel, samples for the cold hardiness evaluation were placed into a glycol-bath exposed to 10 freezing temperatures ranging from -4 C° to -20 C°, and a lethal temperature in which 50% of the floral buds were damaged (LT50) was determined through a visual evaluation of damage to the primary meristem. In ‘Victoria’, the maximum bud break rate was observed once canes accumulated over 900 chilling hours (threshold between 0 and 7.2 C°), while ‘Celestial’ required an additional 300 chill units to exhibit similar rates. Regarding cold hardiness, in ‘Victoria’, the LT50 was between -14 and -16 C° through most of the winter season, while the LT50 for ‘Celestial’ fluctuated between -14 and -16 C° during the fall, then between -18 C° and -20 C° during the winter. The higher cold hardiness observed in ‘Celestial’ is attributed to its genetic traits as a semi-erect cultivar rather than environmental factors. The information from this study will be used to develop a decision-support tool for blackberry growers to reduce loss associated with damage from freezing temperatures in the PNW.

Freezing temperatures limit blackberry (Rubus spp.) growers from meeting their full yield potential in the Pacific Northwest (PNW). Damage from freezing winter temperatures spans a gradient and ranges from complete mortality to partial damage of floral buds and supporting vascular and structural tissues. Partial damage can permit resumption of plant growth but is poorly characterized. Moreover, understanding the mechanisms contributing to this gradient of damage could lead to novel practices focused on mitigation and recovery. The objective of this study was to investigate the relationship between freeze damage and floral bud re-growth. Once chill unit accumulation was sufficient, floricane samples of ‘Victoria’ blackberry were collected for five consecutive weeks during late winter from a commercial farm in Skagit County, Washington. Sampled canes were cut into smaller cuttings, each containing one single floral bud, and exposed to freezing temperatures (-4 C°, -6 C°, -8 C°, -10 C°, and -12 C°) in a glycol bath. The freezing temperature treatments were based on historical freezing temperatures in the area over the past decade during the sample collection period. Treated samples were then placed in suitable growing conditions (22 C°, 16 h light), and shoot growth, chlorophyll fluorescence (Fv/Fm), and gas exchange were measured after three weeks. Shoot growth was delayed from buds exposed to -8 C°, -10 C°, and -12 C° compared to the untreated control. The delay in re-growth is likely explained by limitations in water transportation to the leaves rather than carbohydrate depletion, considering leaf transpiration and stomatal conductance were significantly lower in treated canes compared to the untreated control, while Fv/Fm and carbon assimilation remained unaffected. Findings from this study demonstrate partial re-growth from freeze-damaged blackberry canes and floral buds, and damage to the xylem is likely responsible for reductions in re-growth.

Calcium (Ca) is an important macronutrient for plant health and fruit quality. Insufficient Ca in fruit tissues can lead to physiological disorders that reduce crop quality. To prevent this, Ca fertilizers are frequently applied to soil or plant canopies to increase Ca concentrations in fruits. However, the role of Ca fertilizers in promoting fruit quality and overall yields is poorly understood in raspberry (Rubus idaeus). The objective of this study was to evaluate methods to increase Ca concentrations in raspberry fruits and leaves and assess impacts on yield and fruit quality. Replicated field trials were conducted in 2023 and 2024 using floricane-fruiting raspberry ‘WakeHaven’ ‘Meeker’, and ‘Kulshan’ in Whatcom County, Washington. Treatments included: 1) soil application of Ca fertilizer (gypsum) applied before budbreak, 2) foliar application of Ca fertilizer (calcium hydroxide) applied weekly during immature green to white fruit stage, and 3) an untreated control with no calcium fertilizer. Neither method of Ca application affected yield, fruit quality, soil Ca levels, or Ca concentrations within primocane leaves and raspberry fruits across cultivars. However, in ripe fruit, the concentration of Ca in the receptacles was more than ten times higher than in the drupelets of each cultivar. Cultivars with higher fruit Ca concentration also had higher Ca concentrations in the receptacle (Adjusted R2 = 0.58). These findings demonstrate the important role of cultivar genetics when it comes to explaining variations in fruit Ca concentrations. Moreover, results from this study show that standard fertilizer practices have no impact on fruit Ca concentrations or other important yield and fruit quality variables. A physiological barrier limiting Ca movement from receptacles to fruits was identified, and future studies should further explore what these barriers are, when they develop, and whether they can be adjusted to increase Ca transport to raspberry fruits.

The plant epidermis, despite being a single-cell layer, serves diverse roles in regulating organ growth, responding to environmental cues, and mediating gas exchange and water loss. While extensive research has focused on epidermal differentiation in leaves, where stomata and trichomes play critical roles in overall plant physiology, much less is known about epidermal cell fate on fruit surfaces. Many developing fruits initially contain stomata, but as the fruit rapidly expands, these structures face mechanical strain and often rupture. In several species, this process leads to the formation of lenticels, small, permanently open pores that enable continued gas exchange. While lenticels are essential for gas exchange in certain fruit, their presence and morphologies vary widely across species, and the underlying genetic and developmental mechanisms involved in their formation remain poorly understood. Muscadine, a grape species native to the southeastern U.S., serves as a valuable model for studying lenticel development due to its prominent lenticel formation. In this study, we investigated the cellular transition from stomata to lenticels in muscadine fruit using light and electron microscopy, revealing key stages in epidermal restructuring. Transcriptomic analysis of one muscadine cultivar across four developmental stages of lenticel formation identified candidate genes that may regulate this process. These findings provide insight into the genetic regulation of lenticel development that can help explain natural variation in lenticel traits observed across different muscadine cultivars and fruit species. Further, by drawing comparisons to periderm formation in woody tissues and wound responses in other fruit, this study highlights potential conserved genetic pathways underlying lenticel development. Understanding these processes can provide insights into the role of lenticels in postharvest physiology and contribute to targeted breeding strategies for improving fruit storability.

Vitis shuttleworthii, commonly referred to as callose grape, is a wild grape species endemic to Central and South Florida and serves as a valuable genetic resource for the development of subtropical and tropical scion and rootstock cultivars. V. shuttleworthii can thrive in a humid environment and grows readily in nutrient deficient soils. This species is also resistant to anthracnose, downy mildew, Pierce’s disease and root knot nematodes. This study explores the genetic diversity and phylogenetic relationships among V. shuttleworthii populations sampled from diverse regions across Florida. The overarching objective of the current study is to characterize the extent of natural genetic variation within and among populations and to identify promising genetic sources for resistance to key grapevine diseases. DNA obtained from 72 V. shuttleworthii individuals, along with 25 reference grape accessions, were sequenced using the Illumina platform (2 X 150 bp configuration). We identified over 64 million SNPs from the 97 accessions and 376,753 high-quality SNPs were retained for downstream analysis. Phylogenetic and principal component analyses revealed geographically structured clustering among V. shuttleworthii populations, indicating patterns of local adaptation and evolutionary divergence. The phylogenetic tree delineated clear genetic separation between wild Florida populations and cultivated Vitis species or breeding lines. Principal Component 1 accounted for 61.65% of the variance, while Principal Component 2 explained 9.86% of the variance. This spatial genetic structure suggests significant genetic diversity and restricted gene flow across regions. This study highlights the natural genetic variation present within the V. shuttleworthii population and provides a valuable resource for grape breeding programs.

Plant-parasitic nematodes (PPNs) are common in perennial cropping systems, particularly where traditional fertility and floor management practices biologically disturb soil ecosystems. Four vineyard floor management treatments were applied to mature ‘Norton’ vines—(1) grower control (mown tall fescue in the aisle with herbicide-treated bare driplines), (2) red fescue (creeping red fescue established throughout aisle and dripline), (3) successional cover crops (annual rotation of cereal rye, oats, and sorghum-sudangrass using no-till planting), and (4) compost (a mix of hardwood mulch and composted winery pomace applied across aisle and dripline)—in combination with two nitrogen fertility regimes: no nitrogen (0 lb N/ac) and N fertilization (20 lb N/ac applied at budbreak, bloom, and veraison (60 lb N/ac total)). The study was conducted on a Hosmer silty-clay loam in southern Illinois, arranged in a randomized complete block design with four replications. Soil samples were analyzed for populations of plant-parasitic nematode genera—including Pratylenchus, Helicotylenchus, Xiphinema, and Longidorus—alongside soil nutrient metrics such as water-extractable potassium (WEK), phosphorus (WEP), and organic carbon (WEOC), as well as percent organic matter (OM), carbon-to-nitrogen ratio (C:N), and soil respiration (CO₂). Results showed that red fescue may act as a host for Pratylenchus, particularly when supported by nitrogen fertilization (236/100cc) in the vineyard dripline, compared to 156/100cc under compost, 204/100cc under successional cover, and 164/100cc in the grower control during the same period. The increase may be attributed to red fescue’s weak, fibrous root system, which lacks the structural defenses of deeper-rooted species and may act as an attractant. Although Pratylenchus have higher damage thresholds, these population densities have the potential to affect grapevine health. In contrast, compost and successional cover treatments suppressed multiple PPN genera while significantly improving nutrient availability. Populations of Xiphinema and Longidorus were reduced by 57–92% under compost and successional treatments with no nitrogen, compared to the control. These treatments also increased WEK by up to 249%, raised WEP, and elevated OM to 2.6%, compared to 2.1% in the control. Soil respiration reached 68.4 kg/ha, and estimated nitrogen release was as high as 62.8 kg/ha, while maintaining stable C:N ratios (~12.5), indicating enhanced nutrient cycling and organic matter mineralization. These findings suggest that biologically diverse vineyard floor management can suppress plant-parasitic nematodes while simultaneously improving soil nutrient relationships. Integrating organic amendments and dynamic cover cropping into vineyard systems offers a strategy to reduce pest pressure, enhance nutrient cycling, and build soil health.

A new biostimulant formulation (APH-1035; alkaline Ascophyllum nodosum seaweed extract and amino acid, L-phenylalanine) was evaluated in mode of actions studies to understand the contribution of each active ingredient to the effect of the biostimulant. Previous controlled environment studies showed under salinity and drought stress, plants treated with this new biostimulant had an increase in shoot weight and leaf area, and improvements in photosynthetic parameters, showing statistical synergy between the active ingredients. Field trials had similar results with treated plants having an increase foliar and root fresh and dry weight, and yield under drought and salinity stress. An increase in flowers and fruit set was also seen. Controlled environment studies evaluated the potential mode of action of APH-1035 on strawberry under drought stress. Treatments consisted of a non-stressed control, a stressed control, APH -1035, and the individual active ingredients in APH-1035 (seaweed extract, and phenylalanine) at the equivalent concentrations in APH-1035. Leaf tissue samples were collected pre-stress, and two time points post stress, frozen, and RNA extracted, followed by RNASeq, and subsequent data analysis. Plants treated with APH-1035 showed a transcriptional profile more similar to the non-stressed plants than stressed control plants. The individual active profiles were more similar to the stressed control. Transcript abundance increased over time and did not change after prolonged drought stress. In contrast, stressed control plants, showed down regulation of this gene cluster. Correlation analysis resulted in 221 genes whose expression correlated significantly with treatments. Some of these genes are related to photosynthesis and starch metabolism, which can be linked to drought resistance. These results suggest that the novel biostimulant, with the combination of seaweed extract and an amino acid (phenylalanine) influences gene expression within plants to reduce abiotic stress and promote growth and metabolism under stress, and that this response is greater than the individual actives alone.

A forum for discussion of potential collaborations with regards to fruit, vegetable, and edible crops – i.e. citrus, breeding, production systems, postharvest, pomology, crop management, viticulture, etc.

Due to increasing demand for strawberries (Fragaria × ananassa Duch.) and their health associated benefits, strawberry production has expanded within the United States. Within Texas, strawberry cultivation remains a minor crop (currently less than 162 ha dedicated to strawberry production). However, the state's vast geographic size and diverse climatic conditions present significant opportunities for expanding strawberry production into traditionally non-producing regions. Despite potential for expanding strawberry production, Texas strawberry growers are faced with a number of production challenges. This study aimed to evaluate effects of different shade levels upon gas exchange and production of two strawberry cultivars, ‘Camino Real’ and ‘Albion’ in Lubbock, Texas. Bare root strawberries were planted Fall of 2021 under three shade treatments: Full sun (no shade), 70% full sun, and 50% full sun. Each treatment was applied to 16 plants of each cultivar, with three replications of each treatment. During fall, winter, and early spring, all plants were grown within low plastic tunnels. During the spring production season shade treatments maintained lower air and soil temperatures when compared to the full sun treatment. Light levels were reduced under shade treatments leading to greater leaf gas exchange rates under full sun growing conditions. Marketable yield and berry number for each plant were greater for 'Camino Real' compared to 'Albion', with 'Camino Real' producing twice the yield. Among shade treatments, the 70% sunlight treatment resulted in the greatest marketable yield and berry number for each plant. The lowest yield and berry number for each plant was observed under full sun conditions. Results suggest the interaction between plant cultivar and sun exposure plays a crucial role in determining strawberry yield and quality. Findings highlight the importance of selecting appropriate shade levels and cultivars to optimize strawberry production within demanding environmental conditions.

Strawberry cultivation under a hydroponic system in a protected environment can be the key to enhancing off-season production in the U.S. Yet this type of cropping system remains a challenge. The aim of this study is to evaluate the performance of two day-neutral strawberry cultivars, ‘Albion’ and ‘San Andreas’, grown hydroponically in a greenhouse. Photosynthetic activity, growth and development, fruit yield, and quality have been evaluated for three seasons (2022-2025). The study is conducted at the Plant Science Research Center at Auburn, AL. Environmental conditions are recorded every 15 minutes. So far, the results presented the following: ‘Albion’ and ‘San Andreas’ have shown similarities in photosynthetic response with 15.00 µmol m-2s-1 for ‘Albion’ and 16.03 µmol m-2s-1 for ‘San Andreas’. Growth and development showed that plant height did not differ which is 22.2 cm and 23.9 cm ‘Albion’ and ‘San Andreas’, respectively. Leaf area (cm2) for ‘San Andreas’ is higher, 1679.11, than ‘Albion’, 1091.6. Leaves and stem dry weights (g plant-1) is higher for ‘San Andreas’, 12.89 and 6.63 than for ‘Albion’, 8.77 and 4.25, respectively. Flower and fruit dry weights did not differ for both cultivars. ‘San Andreas’ has a significantly higher yield (g plant-1), 21.80 than ‘Albion’, 17.30. Fruit quality varied between cultivars. ‘Albion’ has a higher brix with 9.15 than ‘San Andreas’ with only 7.85, while ‘San Andreas’ is firmer, 1.13 kg cm-1, than ‘Albion’, 1.03 kg cm-1. ‘San Andreas’ has larger fruits than ‘Albion’, 16.63 cm2 and 14.82 cm2, respectively. Thus, it is feasible to produce strawberries under hydroponic systems in a greenhouse.

Methyl jasmonate (MeJA) is a plant signaling compound known to influence secondary metabolite production, including phenolic compounds and antioxidants. While many studies have shown MeJA’s effects applied to fruit post-harvest, this study aimed to evaluate its effects applied to the foliage and fruit of strawberries (Fragaria × ananassa ‘Seascape’ and Fragaria × ananassa ‘Ft. Laramie’) before harvest, which has been studied to a lesser extent. The effects were measured by evaluating harvest metrics (number of fruits produced and the total mass of fruit per plant) as well as assays quantifying bioactive compounds related to human health. Strawberries were grown using a deep-water culture (DWC) hydroponics system in a controlled greenhouse environment located in Fargo, North Dakota. Plants were treated with MeJA at varying concentrations (0 mM, 0.25 mM, 0.5 mM, 1 mM) as an aqueous solution, with approximately 15 ml sprayed onto the leaves and developing fruit bi-weekly. Fruit extractions in water and 12% ethanol were analyzed for total soluble phenolics and antioxidant capacity using spectrophotometric assays, while enzyme inhibitory activities were assessed using in vitro biochemical inhibition assays. Results were inconsistent across cultivars with 1 mM MeJA increasing the average mass per fruit by nearly 25% for ‘Ft. Laramie’ plants, with little response and no differences for ‘Seascape’ plants. Bioactive assays produced complicated results, with total soluble phenolics peaking at 0.5 mM MeJA for ‘Seascape’ plants while ‘Ft. Laramie’ plants showed a slightly negative trend of TSP in relation to MeJA concentration for first year plants. Results of antioxidant assays, including ABTS radical inhibition and DPPH radical inhibition will be discussed, as will inhibition of enzymes relating to the management of hypertension and diabetes, including α-amylase, α-glucosidase, and angiotensin-converting enzyme.

Strawberries (Fragaria ×ananassa Duch.) are highly perishable and require intensive labor inputs for harvesting. Therefore, yield forecasting is critical for improving labor management and marketing decision-making in strawberry production. In Florida, United States, strawberry yields during winter months have a unique distribution pattern characterized by multiple waves. We hypothesized that individual yield waves can be described using Gaussian distribution, a model that represents a symmetrical bell-shaped curve. Two short-day cultivars (‘Florida Radiance’ and ‘Florida Brilliance’) and one day-neutral cultivar (‘Florida Beauty’) were grown in west-central Florida. Harvesting was performed 30 times, generally twice a week from November through February. Yield data were converted to weekly values prior to model fitting. The first two yield waves were described by a bimodal Gaussian distribution model, which was then converted into two unimodal Gaussian distribution models. The goodness of fit was very high (R2 = 0.934–0.959) for both yield waves in all tested cultivars. Different yield distribution patterns of the tested cultivars were characterized quantitatively by estimating not only the yield but also the timing and duration of each yield wave. Our modeling approach provides insights into understanding cultivar-dependent fruiting phenology, yielding capacity, and fruit earliness. Such information can help optimize yield distribution through breeding and reduce yield gaps by using different cultivars or staggered planting dates. The model developed here only applies to the first two waves of fruit production. Future research will aim to model the following yield waves to fully characterize the strawberry yield distribution.

Fruit firmness is a critical quality trait that influences both postharvest life and potential commercialization of fruits. In cranberry, fruit firmness is highly correlated with the efficiency of producing higher valuable products such as sweetened and dried cranberries (SDC). As in many fruit crops, cranberry firmness declines during ripening, a process often associated with enzymatic solubilization of cell wall polysaccharide. Calcium (Ca) plays a fundamental role in maintaining cell wall integrity by cross-linking with pectins to form calcium pectates, which strengthen the cell wall and limits its disassembly. The objective of this study was to determine changes in cell wall composition through fruit development in two cranberry cultivars with contrasting fruit firmness. Fruit samples were collected every two weeks from 14 to 91 days after full bloom (DAFB) from cranberry ‘Stevens’ and ‘BG’. External fruit quality traits–such as anthocyanin accumulation, fruit size, and weight– were measured alongside internal fruit quality parameters, including internal structure, cell wall composition, and calcium content. Before fruit color developed, both cultivars were similar in size and firmness; however, ‘Stevens’ had higher fruit elasticity compared to ‘BG’. This difference was attributed to lower pectin solubility in the cell walls of ‘Stevens’. As ripening progressed, notable differences in firmness emerged between the two cultivars, particularly between 84 and 91 DAFB. This divergence was associated with increased solubilization of pectins and hemicellulose. Additionally, solubilization of tightly bound hemicellulose was negatively correlated with Ca content in the fruit cell wall. Differences in cell wall-associated Ca content between cultivars were observed throughout fruit development and may explain the variation in firmness at harvest and after 30 days of storage. These findings suggest that cell wall-bound Ca is an important factor influencing fruit firmness and could serve as a valuable selection parameter in breeding programs. Moreover, understanding these differences may aid cranberry growers in in making informed cultivar selection decisions for their plantings.

Olive cultivation in Florida has expanded ten-fold over the last decade, with more than 60 growers managing 800 acres across 26 counties. Despite this rapid growth and rising global demand for olive oil, research on cultivar performance and best management practices in Florida remains limited. In summer 2023, data collection began at three research sites: Jay (northwest Florida), Wauchula (southwest Florida), and Fort Pierce (southeast Florida); to evaluate the adaptability and productivity of select olive cultivars under diverse climatic and soil conditions. Due to differences in grove management and tree maturity, cultivar selection varied by site, with ‘Arbequina’ consistently included in all trials. Additional cultivars included ‘Koroneiki’ and ‘Sikitita’ in Wauchula, and ‘Lecciana’ and ‘Sikitita’ in Fort Pierce. Soil nutrients, leaf nutrients, temperature, moisture, and phenological development were monitored biannually. While no nutrient deficiencies were observed, a significant result emerged: ‘Arbequina’ demonstrated superior adaptability across all three sites, showing higher survival rates and more uniform vegetative growth compared to other cultivars. However, flowering and fruit production patterns remain inconsistent, likely due to climatic variability and limited chilling hours. These findings suggest that ‘Arbequina’ may be viable for Florida conditions, but further data are needed to fully assess yield potential and long-term economic feasibility.

Given the challenges associated with soil fertility management and disease, pest, and weed control in organic strawberry production, different growing practices and systems have been evaluated to address site-specific conditions and constraints. This study was aimed at assessing strawberry cultivar yield responses to the soilless substrate-based tabletop system in organically managed high tunnels. The research trial was carried out on certified land at the University of Florida Plant Science Research and Education Unit in Citra, using a split plot design with four replications (each high tunnel serving as a replication). The tabletop strawberry troughs (1 m long) were filled with the soilless substrate consisting of a mixture of pine bark and locally available composts for growing seven strawberry cultivars, including ‘Ember’, ‘Encore’, ‘Florida Beauty’, ‘Florida Brilliance’, ‘Florida Felicity’, ‘Florida Medallion’, and ‘Florida Pearl’, at two spacings, i.e., 6 plants/trough (S6) vs. 8 plants/trough (S8). Spacing was the whole plot factor and strawberry cultivars were included in the subplots, with two troughs as an experimental unit. In addition to preplant incorporation of the granular organic fertilizer into the substrate, liquid organic fertilizer was applied throughout the production season. Bare-root strawberry plants were transplanted into the tabletop troughs inside high tunnels in October 2024 and the first harvest took place in late November. Fruit yield data were analyzed for the harvest period from November 2024 to early May 2025. ‘Encore’ and ‘Florida Felicity’ were top performers in terms of whole-season marketable fruit yield, while ‘Florida Brilliance’ exhibited the lowest yield potential. ‘Encore’ showed the highest average marketable fruit weight, whereas ‘Florida Pearl’ produced the smallest fruit. The whole-season marketable fruit yield and number per plant were significantly higher at S6 vs. S8, while a significant cultivar by spacing interaction was observed for marketable fruit yield and number per trough. On a per trough basis, ‘Florida Felicity’ and ‘Encore’ produced higher yields at S8 vs. S6, whereas other cultivars yielded similarly between the two spacings. ‘Florida Felicity’, ‘Encore’, and ‘Ember’ demonstrated great potential for producing early yields in this high tunnel tabletop system. Moreover, ‘Florida Felicity’ was the top yielding cultivar during the late season (mid-March to early May). Phytophthora crown and root rot and powdery mildew were among the major plant diseases detected in this study, while varying levels of disease susceptibility and plant health were observed among strawberry cultivars.

This study evaluated physiological and fruit quality traits of 24 intraspecific hybrid maypop (Passiflora incarnata) (Florida × Oklahoma) selections, grown in 3-gallon pots at the Mississippi Agricultural and Forestry Experiment Station South Mississippi Branch in Poplarville, Mississippi, in 2023. Summer physiological measurements revealed significant differences in stomatal conductance, ranging from 0.02 to 0.89 mol/m²s (0.29 mol/m²s average), transpiration, ranging from 0.31 to 7.98 mmol/m²s (3.65 mmol/m²s average), vapor pressure deficit, ranging from 0.83 to 2.56 kPa (1.51 kPa average), chlorophyll fluorescence, ranging from 0.38 to 0.67 (0.53 average), and fruit temperature, ranging from 32.00 to 39.33 °C (34.96 °C average) among selections. Significant differences were also observed in fruit size parameters, including height (45.53-64.94 mm; 56.94 mm average), width (33.83-56.32 mm; 49.56 mm average), shape (1.03-1.36 mm/mm; 1.16 mm/mm average), weight (15.41-59.66 g; 36.62 g average), and density (0.89-1.67 g/cm²; 1.25 g/cm² average). Pulp content also significantly differed, with total soluble solids ranging from 13.57 to 18.73 °Brix (15.90 °Brix average), titratable acidity from 14.77 to 23.33 g/L (17.96 g/L average), pH from 3.38 to 3.81 (3.59 average), total phenolic content from 363.72 to 603.88 mg GAE/L (481.33 mg GAE/L average), lightness (L*) from 73.94 to 80.91 (77.76 average), red-green value (a*) from -5.36 to 0.43 (-2.38 average), and yellow-blue value (b*) from 25.94 to 54.20 (39.62 average). Additionally, differential thermal analysis of the roots of these selections as well as their parents, revealed potential cold hardiness differences within P. incarnata, with Oklahoma roots exhibiting greater hardiness (-14.42 °C average) than Florida roots (-8.26 °C average), and hybrids showing intermediate tolerance (-10.53 °C average). Overall, these findings highlight the variability within P. incarnata, offering valuable insights for broader breeding efforts focused on enhancing both fruit quality and physiological traits within Passiflora.