ASHS 2024 Conference

Assessing Apple Cultivar Responses to Low Oxygen Limit Determination Using Chlorophyll Fluorescence and Respiratory Quotient - Hnin Phyu Lwin
Understanding how physiological maturity and storage regime affect skin greasiness on WA 38 apples - Carolina Torres
Chlorophyll to Carotenoid Ratio Measured Nondestructively Correlates with Peel Pigment Content and Canopy Attachment Position of ‘Granny Smith’ Apples - Manoella Mendoza
Early Spectral Differences on Scald Disorders in ‘Granny Smith’ Apples - Rene Mongollon
Apple Ripening After DCA Storage: Assessing The Risk Of Flavor Loss - Randolph Beaudry
The Impact Of Hot Water Treatment On Organic Apple Quality With Different Storage Systems - Sadat Amankona
Fungicides and Scald Inhibitor Diphenylamine Shift Microbiomes of ‘Fuji’ Apples Through Short Term Cold and Room Temperature Storage - Connor Lane
Pyrus communis: A Model for Studying Climacteric Ripening and Senescence - Amit Dhingra
Characterization of Postharvest Rots and the Susceptibility to Decay of 38 European Pear Genotypes during Cold Storage. - Tamara Collum

Dynamic controlled atmosphere (DCA) is a prominent technology used worldwide for long-term apple storage. In Washington, the adoption of DCA technologies to manage low oxygen levels is limited, partly because the benefits are not clearly demonstrated for some major cultivars, such as ‘Honeycrisp’ and new varieties like ‘WA 38’. The response of ‘Honeycrisp’, ‘Gala’, and ‘WA 38’ apples to lower oxygen levels was monitored monthly until 8 months of storage (1oC or 3oC) through chlorophyll fluorescence (CF) and respiratory quotient (RQ) by a stepwise decrease in O2 levels at each time point during 2023/2024 season. Ethanol and acetaldehyde concentrations were obtained from fruit juice before and after the lower oxygen limit (LOL) determinations. ‘Honeycrisp’ and ‘Gala’ apple cultivars showed differences in LOLs determined through CF or RQ. CF LOL for ‘Honeycrisp’ was approximately 0.3-0.2 kPa O2 compared to 0.1 kPa O2 for ‘Gala’ while RQ response occurred at 0.1 kPa O2 level in both cultivars. ‘WA 38’ apples displayed inconsistent CF responses at 0.3 and 0.4 kPa oxygen levels. Ethanol concentration increased after low oxygen stress irrespective of the cultivar. During the first month of storage and after the low oxygen stress, ‘Honeycrisp’ apples accumulated (in average) 120 ppm of ethanol, ‘Gala’ 2.92 ppm, and ‘WA 38’ 4.24 ppm. Towards the end of storage, the ethanol concentration showed an increase for ‘Gala’ (25 ppm), which was not observed for the other two cultivars. Small amounts of acetaldehyde were accumulated only in ‘Honeycrisp’ apples. This study highlights the different responses of apple cultivars to low oxygen stress during the lower oxygen limit (LOL) determination, with ‘Honeycrisp’ being the most sensitive one among the cultivars tested. Further seasons are needed to confirm these results and include the seasonal-dependent responses in each cultivar.

‘WA 38’ (Cosmic Crisp®) is the newest cultivar released by the Washington State University apple breeding program, and today in its sixth year of commercial production in WA. This cultivar has a high pack-out, i.e. highly colored fruit and few external and internal defects. Nevertheless, skin greasiness has been one of the main defects at harvest and postharvest, making waxing during packaging challenging, and affecting the cosmetic appearance. Since the starch degradation index is the only maturity index used to commercially harvest WA 38, the correlation between maturation and the onset of greasiness was studied during two seasons. Different maturity indices pre-and postharvest (firmness, soluble solid content, internal ethylene concentration (IEC), starch index (1-6), IAD values) along with skin greasiness were evaluated from 3-4 weeks before harvest (WBH) until 6 months in air (1oC) or controlled atmosphere (2.5 kPa O2, 1.5 kPa CO2) storage in fruit from four commercial orchards (#1 to #4; 2nd-4th-leaf). In 2022 and 2023 the rate of change of all maturity indices were block-dependent. In both years, IEC was detected in up to 80% of the fruit sampled four WBH in orchard #1 (average 0.3 ppm). At this same time point, only 16% of the fruit had started the starch degradation process (SI=1.5/6.0). The climacteric peak occurred 3-5 months into cold storage, and it was block-dependent. Greasiness on fruit skin was detected 2 WBH in two of the four orchards in 2022; in 2023 this occurred at commercial harvest. Overall, there was a higher incidence (and severity) of greasiness in fruit from air storage compared to CA, and in both cases, it increased during the shelf-life period (7 d at 20oC). The results indicate that fruit greasiness appears to be more related to fruit maturity and perhaps seasonal weather than tree age, nevertheless, additional seasons are needed to confirm these results.

‘Granny Smith’ is an important apple variety for Washington State, where it has consistently been ranked as the third most-produced conventional cultivar since 2017. This apple variety is highly susceptible to sunscald, a sun-stress-related postharvest disorder that typically appears after three months of cold storage and makes apples unmarketable. Previous research has shown that a decrease in chlorophyll (chl) and an increase in carotenoids (car) in fruit peel have been associated with increased sunlight exposure and the development of sunscald. In order to assess the use of the chl/car ratio measured non-destructively with a Vis/NIR hyperspectral imager as a predictive index for sun exposure and sunscald development postharvest, ‘Granny Smith’ apples were picked from the periphery and inner canopy sections of the tree in 2021 and 2023 seasons. Fruit position in the canopy was documented during sampling and later correlated with hyperspectral images, chlorophyll, and carotenoid content in the peel. Subsequently, the collected peel sample was immediately frozen with liquid nitrogen and stored at -80°C. The chl/car ratio obtained from the reflectance values from the hyperspectral images was well correlated (r2 = 0.82) with the destructive determination of the ratio. Based on k-means clustering analysis, samples were grouped in accordance with the chl/car ratio and associated with fruit position on the tree. Apples with the highest chl/car ratios (1.4 to 1.7) were those located on the shaded portion of the trees. Apples with sunburn had the lowest chl/car ratios (0.1 to 1.2) and were located on the periphery of the tree. The results indicate that the chlorophyll to carotenoid ratio measured non-destructively at harvest can potentially be used for pre-storage sorting of ‘Granny Smith’ apples based on relative sun exposure and sunscald susceptibility, reducing postharvest losses. However, the establishment of the index reliability can benefit from additional years of data collection.

‘Granny Smith’ apples are highly susceptible to skin browning (=scald). These disorders can significantly reduce fruit’s marketability due to their unattractive appearance. Superficial scald and sunscald have different etiologies but their symptoms are similar and easily mistaken. The oxidation of α-farnesene causes superficial scald (SS); on the other hand, sunscald (SC) is a non-oxidative process that affects only the sunlit sides of the fruit. To correlate the spectral fingerprint with fruit susceptibility to these disorders, hyperspectral images (400-1000 nm, 640x865 px; Headwall Photonics, Bolton, MA) were taken at harvest from sun-exposed and unexposed sides of the fruit (n=216; ~26,000 px) and later, after six months in air storage (33 oF), correlated with scald incidence. The dataset grouped 145 asymptomatic, 117 with SS and 170 with SC fruit. After pre-processing spectral information (Savitzky-Golay dev, standard normal variate), iPLS wavelength selection showed that bands from 400 to 650 and 900 to 950 nm were the most accurate for at-harvest spectral differentiation between superficial and sunscald symptoms. A neural network classification model was trained (18,226 px) and validated on an independent dataset (7,808 px), achieving overall accuracies of 78 % and 73 %, respectively. After prediction, SC px obtained the highest classification metrics (accuracy 87 %, precision 86 %); meanwhile, the asymptomatic class showed the lowest metrics (accuracy 74 %, precision 60 %). These preliminary results showed that in the same way, sunscald could be identified close to harvest using hyperspectral fingerprints, superficial scald could also be predicted at harvest on susceptible fruit and differentiated from sunscald susceptible fruit.

Dynamic controlled atmosphere (DCA) storage suppresses the ripening of apple fruit during storage to a greater extent than standard CA storage. DCA is a relatively new technology, and it has the potential to markedly alter the volatile profile of apple fruit. It has been found that DCA storage can suppress the most important aroma volatiles of stored apple fruit. What we don't know is the length of time and the conditions needed to recover that loss in aroma, especially when DCA is applied in combination with the ethylene action inhibitor 1-methylcyclopropene (1-MCP). A critical concern about 1-MCP is that apple flavor is compromised in treated fruit because aroma volatiles are so closely linked with ethylene response. Apple fruit from high-value cultivars were stored under a DCA regimen (approximately 0.4% O2), with and without 1-MCP treatment, for 3, 6, and 9 months. Following removal of fruit from DCA, the volatile profile and fruit quality traits were measured for up to 5 weeks while being held at room temperature. The recovery of aroma formation following storage for 6 months was essentially immediate for ‘Red Delicious’ fruit if 1-MCP was not used. The recovery was a little slower for one of the replicate studies if DCA was used. If the fruit were treated with 1-MCP, there was a 2-week delay in the recovery of aroma formation. ‘Evercrisp’ aroma formation was much lower than ‘Red Delicious’ and the responses to DCA and 1-MCP differed from that of Red Delicious. Aroma formation remained very low for 3 to 4 weeks at room temperature following CA and DCA storage and never recovered following 1-MCP treatment for the 5-week duration of the study. The data for aroma formation after 9 months was similar to that at the 6-month time point for ‘Red Delicious’ in terms of 1-MCP responses. However, the effect of DCA seemed to be more pronounced, suppressing aroma recovery for an additional week at room temperature. For ‘Evercrisp’, the 9-month data were quite similar to those from 6 months storage.

There has been a surge in demand for organic apples in the U.S. in the last decade. Washington State supplies more than 90% of them because of the ideal climate and soil conditions that favor production. Thermotherapy methods are widely used in Europe to reduce postharvest rots, but they have not been adopted in the U.S. because of their potential detrimental effects on fruit quality. The objective of this research was to evaluate the impact of hot water treatments at harvest on fruit quality during long-term storage. ‘Royal Gala’ and ‘Honeycrisp’ apples were immersed at 49 °C or 52 °C for 2 minutes in a controlled hot water bath immediately after harvest. After fruits were dried at 20 °C, they were placed in controlled atmosphere (CA; 2 kPa O2, 0.5 kPa CO2, 1°C-‘Royal Gala’, 3oC-‘Honeycrisp’) and air (RA; 1°C-‘Royal Gala’, 3oC-‘Honeycrisp’) storage for up to 9 months. Fruit quality (firmness and titratable acidity), defects, and physiological disorders were evaluated 1 and 7 days at 20 °C. In general, ‘Royal Gala’ apples immersed at 49 °C and stored in CA had no decay after 3 and 6 months of storage, but it was the highest (around 9%) in ‘Honeycrisp’ in both CA and RA. Peel damage was less at 49 °C for both ‘Royal Gala’ (RA-1.3%; CA-5%) and ‘Honeycrisp’ (RA-7.4%; CA-2.8%) compared to 52 °C after 3 months. Fruit firmness and titratable acidity were statistically different (p≤0.05) at 49 °C compared to 52 °C after 3 months. Although the hot water treatment in ‘Royal Gala’ apples was effective in reducing decay incidence without compromising fruit quality, the opposite was found in ‘Honeycrisp’; therefore, further research is needed to confirm these results and understand the variety-dependent effect.

Recent studies have shown that the native microbiome plays an important role in biocontrol efficacy, but in comparison less is known about how the microbiome responds to conventional and natural product fungicides. This study investigated the effects of conventional fungicide fludioxonil, natural product fungicide natamycin, and scald inhibitor diphenylamine (DPA) on the microbiomes of ‘Fuji’ apples (Malus x domestica) from 1-28 days of cold storage and 7 days of room temperature after the cold storage. We hypothesized that fludioxonil would have a smaller effect on the microbiome than natamycin due to being more limited in targeting specific pathogens, and that antioxidant activity from DPA would shift the microbiome. DPA showed a strong effect on the fungal microbiome that increased with storage time, while natamycin resulted in modest fungal shifts and fludioxonil resulted in no observed shifts. While chemical treatment was not a predictor of bacterial microbiome variation, bacterial communities shifted throughout storage with many of the trends reversing when samples were removed and left at room temperature. Time in cold storage decreased the relative abundance of Pseudomonas and DPA application reduced the relative abundance of Aureobasidium, both notable biocontrol genera. These results highlight how chemical applications like DPA may have unintended effects on beneficial microbes that protect crops from pathogen infection.

Fruits constitute a critical part of a healthy diet. However, they often perish prior to consumption due to unpredictable ripening. Especially in climacteric fruit, blockage in the perception or synthesis of ethylene has been used to prolong shelf life. European pear (Pyrus communis) are classified as climacteric fruit. However, System 2 ethylene production requires a genetically pre-determined period of cold conditioning, which triggers ripening—in addition, applying 1-MCP, an ethylene perception inhibitor, indefinitely blocks ripening. Using a physiological and developmental transcriptomics approach, we have shown that in 1-MCP fruit stored in a controlled atmosphere, activating alternative respiration via glyoxylic acid stimulation of AOX expression can reverse the effect of 1-MCP. Interestingly, 1-MCP fruit without CA storage responds differently to glyoxylic acid. It shows classic signs of senescence. The underlying processes of ripening and senescence can be discerned by utilizing the fruit that has been treated differently post-1-MCP application. This knowledge is expected to aid in identifying strategies to prolong fruit shelf life.

Phytopathogenic fungi can cause rots during cold storage leading to the loss of pear fruit and significant economic costs. Currently, all commercially available pear varieties are susceptible to postharvest rots. Genetic resistance to fruit rot pathogens including Penicillium expansum and Colletotrichum spp. has been identified in wild apple germplasm. The objective of this study was to evaluate diverse genotypes of European pears (Pyrus communis L.) for disease incidence during cold storage and evaluate susceptibility to prevalent phytopathogenic fungi by directly challenging fruit using a wound inoculation method. Fruit from 38 pear genotypes were harvested at maturity, then evaluated weekly for the presence of postharvest rots during cold storage. If rot was observed, the diseased fruits were removed from cold storage and fungal isolates were collected from fruit with disease symptoms. The identity of fungal isolates was determined based on morphology and genetic sequencing of marker genes including ITS and TEF1. After 12 weeks in cold storage, the incidence of rot ranged from 8.3% to 100%. Colletotrichum was the most prevalent genus isolated from the rotting pears. Twenty pear genotypes were directly challenged with P. expansum or C. fioriniae using a wound inoculation method on fruit that was harvested at commercial maturity. Five genotypes had significantly reduced disease development when challenged with P. expansum compared to susceptible varieties Gem and Bartlett. Four of these five genotypes also had significantly reduced disease development when challenged with C. fioriniae. One additional genotype was found to have significantly reduced disease development when challenged with C. fioriniae but was highly susceptible to P. expansum. These results will be a valuable resource for pear breeders and aid efforts to develop European pear varieties that have genetic resistance to fruit rot pathogens.

Leaf Culture and Regeneration in Two Cultivated Strawberries (Fragaria x ananassa) - Kedong Da
Leaf Culture and Regeneration in Hydrangea Macrophylla - Kedong Da
Immature Embryo Germination of Camellia sinensis (L) O. Kuntze. - Sarita Paudel
Development of an In Vitro Transformation System for Gene Editing Powdery Mildew Resistance in Gerbera jamesonni - Heather Gladfelter
Declining Phosphorus Availability Increases Sucrose Synthase Activity and Storage Root Formation in Sweetpotato cv Beauregard Adventitious Roots - Marissa Barbosa

Strawberry (Fragaria × ananassa) holds significant commercial importance as a fruit crop. Tissue culture regeneration techniques offer a promising avenue for rapid propagation, genomic study, and biotech breeding, including genome editing and genetic transformation. However, literature reports on cultivated variety-based strawberry regeneration and transformation/genome editing is limited. This study aims to investigate the influence of various tissue culture conditions on the regeneration efficiency of two major cultivated strawberry varieties, 'Chandler' and 'Festival', by assessing the impact of different culture conditions and hormonal treatments on the regeneration of selected varieties' in vitro leaf cultures. The first three open leaves from 4-week-old in vitro cultures were collected and cultured on Murashige and Skoog (MS) medium supplemented with varying concentrations of Thidiazuron (TDZ) (0, 0.5, 1, 2, 4 mg/L) combined with 2,4-dichlorophenoxyacetic acid (2,4-D) (0.2 mg/L). The cultures were maintained in a growth chamber with varying light (dark/light) and photoperiod conditions. Regeneration parameters, including regeneration rate, regeneration number, and root development, were recorded over an 8-week period. Preliminary results indicate a significant influence of TDZ concentrations and light conditions on shoot regeneration rate and number. The combination of TDZ at 1 mg/L and 2,4-D at 0.2 mg/L under a 20-day dark pretreatment followed by a light (16/8-hour) condition resulted in the highest regeneration efficiency. Rooting was observed when the cultures were transferred to a hormone-free MS medium.

Hydrangea is a genus of flowering plants that includes a diverse range of species and cultivars. These plants are known for their large, showy flower heads and are commonly grown as ornamental shrubs in gardens and landscapes. Hydrangea macrophylla, commonly known as bigleaf hydrangea, is a popular ornamental shrub in the hydrangeaceae family, well-known for its large, showy flower heads and broad leaves. Tissue culture regeneration techniques offer a promising avenue for rapid propagation, genomic study, and biotech breeding, including genome editing and genetic transformation. However, literature on hydrangea macrophylla regeneration and transformation/genome editing report is limited. This study aims to investigate the influence of various tissue culture conditions on the regeneration efficiency of Hydrangea macrophylla 'Blaumeise,' 'H2020-59,' and 'H15298' by assessing the impact of different culture conditions and hormonal treatments on the regeneration of selected varieties in vitro leaf cultures. The first three open leaves from 4-week-old in vitro cultures were collected and cultured on Murashige and Skoog (MS) medium, supplemented with varying concentrations of 6-Benzylaminopurine (BAP) (0, 0.5, 1, 2 mg/L) combined with 1-Naphthaleneacetic Acid (NAA) (0.01 mg/L). The cultures were maintained in a growth chamber with varying light (dark or light) and photoperiod conditions. Regeneration parameters, including regeneration rate, regeneration number, and root development, were recorded over a 4-week period. Preliminary results indicate a significant influence of BA concentrations and light conditions on shoot regeneration rate and number. The combination of BA at 2 mg/L and NAA at 0.01 mg/L under dark conditions resulted in the highest regeneration efficiency. Rooting was observed when the cultures were transferred to a hormone-free MS medium.

Camellia sinensis (L.) O. Kuntze is a woody perennial, evergreen shrub or small tree native to Southwest China, whose leaves are processed into various types of teas for consumption. Harvesting mature tea seeds typically requires 12 to 14 months, with an additional 2 to 3 months needed for germination using traditional methods. In an effort to expedite this breeding cycle, we conducted aseptic germination experiments on immature embryos of Camellia sinensis fruits collected from different months, spanning from May to September. Visible embryos were observed in immature fruits harvested in late July, exhibiting an average size of 2.17 ± 0.33 cm, and demonstrated germination capabilities only after mid-August. These embryos were excised and cultured on Murashige and Skoog (MS) medium supplemented with 3% sucrose and 0.65% agar. Cultures were maintained in a growth chamber set at 24°C under a 16-hour photoperiod. To enhance the germination process, cultures were kept in darkness for the initial two weeks. Immature embryos initiated germination approximately one to two weeks after the initiation of culture. After two months, plantlets were transplanted into a substrate consisting of peat moss and perlite (1:1 v/v) and acclimatized in a mist system within a greenhouse. Five month post-culture initiation, the average shoot length, root length, and leaf number of transplanted plantlets were recorded as 2.24 ± 0.89 cm, 5.61 ± 4.58 cm, and 8.36 ± 2.84, respectively. Preliminary findings suggest promising outcomes, demonstrating the feasibility of in-vitro embryo germination in tea plants. This methodology holds the potential to mitigate late-term abortion of hybrid embryos and significantly shorten the breeding cycle, critical aspects in breeding triploid tea varieties through crossbreeding diploid and tetraploid tea plants.

Gerbera is among the significant players in the global cut flower market, valued at 30 billion USD in 2023. Gerbera daisies, along with chrysanthemums are the largest segment of the cut flower market with a share of 40%. The quality and quantity of gerbera cut flower production is negatively impacted by the fungal disease powdery mildew causing a significant loss of revenue. Effects from powdery mildew infection include reduced flower quality, stunted growth, decreased flower longevity, and decreased marketability. Powdery mildew is currently controlled using fungicides which increases the cost of cut flower production and has the potential for the fungus to develop resistance to the fungicides. One strategy is to use gene editing and CRISPR technology to produce gerbera plants resistant to powdery mildew. The gene “mlo” which stands for “Mildew Locus O” plays a crucial role in the plant’s defense against powdery mildew infections. Plants with mutations in the “mlo” gene exhibit a type of broad-spectrum resistance providing protection against various strains of powdery mildew. We developed a tissue culture regeneration and transformation system for the Gerbera jamesonii cultivar ‘Flori Line Maxi Yellow’ which is sensitive to powdery mildew. The Agrobacterium tumefaciens strain GV3101 containing a binary plasmid encoding for an enhanced GFP marker gene and hygromycin selection gene was used to develop the transformation system. Young, 10mm sized in vitro leaves with part of the petiole were used as explants. A sensitivity test with the explants showed hygromycin at 7.5 mg/L was optimal for selection of callus with positive GFP expression. The next step is to regenerate GFP plants to confirm successful transformation and design CRISPR constructs to inactivate the “mlo” gene in the powdery mildew sensitive gerbera cultivar via gene editing.

Sucrose Synthase (SuSy) plays a crucial role in sugar metabolism mainly in the sink tissues of plants. In sweetpotato, increased SuSy activity has been associated with increased storage root development and correlated with sink strength. However, little is known about the specific variables associated with increased SuSy activity. Evidence from model systems supports the hypothesis that phosphorus (P) starvation is associated with increased accumulation of carbohydrates in roots. In the first study, we measured SuSy gene expression in ‘Beauregard’ sweetpotato grown in a split root system and subjected to the following P treatments: positive control ( / ), negative control (0/0), declining P (-/-), and split P ( /-). The declining P treatment corresponded to 25, 50, 75 and 0% progressive reduction in P and was imposed on days 6, 9, 12, and 15, respectively. A second study was conducted to measure storage root development at 50 days. The (-/-) treatment was associated with increased SuSy activity in developing adventitious starting at 11 days after planting. Moreover, plants grown with the declining P treatment produced storage roots with larger diameter (>2cm) significantly higher than the positive control. Decreased SuSy activity was associated with reduction in storage root number among P-deficient (0/0) plants. Taken together, these results support the hypothesis that P availability in the root zone is associated with sink strength and storage root formation signaling in adventitious roots. These findings can be used to develop tools and management practices to increase P fertilizer efficiency for consistent storage root yields in sweetpotato.

Exploration of Salt-Tolerant Germplasm to Increase Specialty Rice Production in South Carolina - Gursewak Singh
Independent Domestication of Cucumber (Cucumis sativus L.) Fruit Revealed by Cucurbitacin and Volatile Compound Profiling - Eun Jin Lee
Evaluation of watermelon and Citrullus crop wild relatives for resistance to whiteflies and whitefly transmitted viruses - Alexander Luckew
Development of Specialty Pumpkin Cultivars with Potential to be Released for Organic and Conventional Resilient Cropping - Angela Linares Ramirez
SSR Marker Development and Fine Mapping of Linkage Group 2 Eastern Filbert Blight Resistance from ‘Georgian OSU 759.010’ - Brianna Heilsnis
Enhancing the Fruit Set of NJ BP1-1 Beach Plum (Prunus maritima) - Megan Muehlbauer
The wonderful world of worms: Microbiota of rabbit manure vermicompost at different maturities - Amanda Birnbaum

The significance of Carolina Gold specialty rice in South Carolina's (SC) agricultural history is deeply rooted, dating back to colonial times. Its unique flavor and texture have made it a prized variety among chefs and food enthusiasts. Currently, saltwater intrusion and weed infestation threaten this specialty rice production in SC. Understanding salt tolerance and weed interactions is crucial for ensuring the continued production and quality of this specialty rice. Preliminary experiments assessed the impact of different concentrations of ocean water and native weed pressure on rice plant vigor when cultivated organically under controlled environmental conditions. In brief, we screened rice germplasm under various seawater concentrations (0, 0.375, 0.75, 1.5%, and 3%) in both weed-free and weed competition conditions. In our preliminary greenhouse studies, we observed weed competition reduced the rice plant biomass by 2-3 times and yield up to 5 times at a 3% seawater concentration. M202 and Doble Carolina exhibited the highest salt tolerance and higher photosynthesis rate when compared to local genotypes, Carolina Gold and Santee Gold. The cultivars demonstrating superior performance under these conditions were subsequently subjected to further testing in organic research plots, incorporating supplemental irrigation with tidal ocean water. A field experiment was designed to evaluate and validate the salinity tolerance of six rice genotypes (Carolina Gold, Santee Gold, Doble Carolina, M202, Jupiter, and JN100) under different seawater concentrations (0%, 1.5%, 3%, 6%, and 12%), both in weed-free and weed-competition scenarios. Using a gasoline pump, we collect brackish water from the adjacent marsh in a 4000-gallon-capacity reservoir/pool. The calculated volumes are then pumped into the field plots based on each plot's fresh and seawater volumes. The salinity level of treated plots is monitored by measuring the EC values. The results indicated that M202, Doble Carolina and JN100 showed the highest salt tolerance. Weed competition reduced the rice plant height, number of tillers, panicles, dry root, and shoot weight across the entire salinity gradient. Weed competition led to an approximately 50% reduction in both the aboveground (shoot) and belowground (root) weights of rice plants, as compared to weed-free plots, across the tested salinity levels. Weed biomass, weeding time and regrowth of weeds declined significantly above 3 % seawater concentration when compared to control. Eventually, the most promising cultivars identified are being incorporated into a breeding program to integrate salt-tolerant genes into the Carolina Gold specialty rice.

Cucumber (Cucumis sativus L.) fruit has characteristic taste and aroma, the important organoleptic qualities influencing consumer preference and marketability. Profiling of metabolites conferring bitterness and aroma is required to improve cucumber fruit quality and produce preferred fruit. In this study, we profiled cucurbitacins responsible for bitterness and volatile compounds using fruit of 69 cucumber genotypes with different fruit shape, color, and origin and provided qualitative and quantitative information of metabolites involved in the organoleptic quality. Among six types of cucurbitacis (CuA-E, I), only CuC was detected in six inbreds while most genotypes didn’t contain them. It means bitterness has been lost in modern cucumber cultivars with domestication process. The 69 genotypes were classified into four clusters according to the profiles of cucurbitacins and volatile compounds. Clusters 2 and 3 accumulated the highest and lowest volatile contents, respectively. Clusters 1 and 4 were discriminated by minor volatiles rather than major ones, suggesting they have distinct background flavor. Clusters 1 and 4 also showed different phenotypes such as length and color, implying a relationship between fruit phenotype and background flavor. However, the clustering was inconsistent with cultivar types or origins. It suggests independent domestication for bitterness and flavor has been conducted for cultivars in different origins. We further examined hybridization effect on metabolite compositions using 15 F1 hybrids from selected inbreds. Total volatile compound (TVC) content was reduced in the F1 hybrids, especially due to decrease in total alcohol content affecting increase in ratio of aldehyde to TVC. These findings will contribute to improvements of cucumber organoleptic qualities and will provide useful information for selecting cucumber materials to produce preferred fruit.

In the Southeastern U.S., cucurbit production is vulnerable to the sweetpotato whitefly Bemisia tabaci and the viruses it transmits. There are limited control methods for the whitefly pest, including mulches, row covers, and spray programs. Unfortunately, none of these practices reduce the whitefly populations to zero, leaving whiteflies behind to transmit viruses. Therefore, host resistance is the best management practice, and the identification of resistant genotypes to whitefly transmitted viruses is a top priority. To aid watermelon breeding for resistance, 21 Citrullus genotypes were evaluated over two field seasons in Tifton, GA in 2022 and 2023. The traits evaluated were viral disease severity (AUDPC), Cucurbit leaf crumple virus (CuLCrV), Cucurbit yellow stunting disorder virus (CYSDV), and Cucurbit chlorotic yellows virus (CCYV) viral loads and in 2022 only, whitefly counts were collected to evaluate whitefly preference. Leaf tissue was collected 5 weeks after transplanting (WAT) in 2022 and 7 WAT in 2023. Total nucleic acids were extracted, and qPCR was performed to determine viral loads. Grif 16444 was the only genotype that had lower adult whitefly counts, indicating non-preference of this genotype. Over the two years there were three consistent genotypes with the statistically lowest AUDPC, two C. mucosospermus (PI 595203 and PI 494528) and one C. ecirrhosus (Grif 16444). In 2022, these three genotypes had significantly lower CuLCrV viral loads than the cultivar checks, however, in 2023 due to low CuLCrV presence there were no significant differences. For CYSDV and CCYV, there were no genotypes with significantly lower viral loads than the cultivar checks in both years. These wild crop relatives provide sources of resistance that can be used by breeders to improve cultivated watermelon.

Specialty pumpkins, such as the tropical pumpkin or “calabaza” (Cucurbita moschata Duchesne), are widely grown and consumed in Puerto Rico, ranking second among the most important vegetables on the island. This crop is also increasingly becoming a lucrative emerging market in the United States, particularly in communities with a high density of households of Latino/Hispanic and Caribbean heritage. Yield, fruit quality, and disease resistance of 21 genotypes were evaluated under conventional and certified organic management conditions in Puerto Rico at the University of Puerto Rico Lajas Research Station from January to May 2022, and from November 2022 to March 2023. The genotypes were evaluated using a randomized complete block design with three replications. The number of marketable fruits, total fruits per plot, yield (kg ha-1), and incidence of whiteflies, among other variables, were recorded. Overall, the number of fruits per plot and marketable fruits ranged from 2 and 12, while the yield reached 9,229 kg ha-1 to 65,707 kg ha-1. Under organic certified management, the highest yield was obtained by UFTP42 with 46,567 kg ha-1, while UFTP4 obtained the lowest yield with 5,110 kg ha-1. Under conventional conditions, the UFTP34, UFTP80, and ‘Soler’ lines obtained the highest performance, with 66,677; 63,974, and 75,971 kg ha-1, respectively. On the other hand, the genotypes UFTP4, UFTP10, UFTP22, and UFTP46 obtained lower yields with 9,229; 10,881; 17,635, and 15,408 kg ha-1, respectively. Verde Luz, showed the lowest incidence of whiteflies (< 10%), under both management conditions, while the remaining genotypes showed no significantdifferences between them. In summary, UFTP34, UFTP44, UFTP45, and UFTP80 could be released as prospective cultivars for the southern area of Puerto Rico and could be used as parents for breeding purposes under organic and conventional cropping systems.

Anisogramma anomala, causal agent of Eastern Filbert Blight (EFB), is endemic to eastern North America and was accidentally introduced to the Pacific Northwest hazelnut (Corylus avellana) growing regions around 1960. A single gene conferring resistance was identified in the pollinizer ‘Gasaway’ by the OSU Hazelnut Breeding Program, and deployed across the Willamette Valley in the majority of cultivars released since 2008. In preparation for a mutation or second accidental new introduction, research has focused on discovering, mapping, and developing useful molecular markers for new sources of resistance. In October 2023, a new isolate of A. anomala was detected in a grower’s orchard in Woodburn, OR, growing on the previously resistant ‘Jefferson’. The results of this study focus on linkage group 2 resistance (LG2), conveyed by ‘Georgian OSU 759.010’. Using two populations from a cross between ‘OSU 1477.047’ with Georgian resistance and ‘Sacajawea’ with quantitative resistance, n=272 recombinant offspring were identified using existing SSR markers. Marker development resulted in 40 new SSR markers covering an 8.5Mbp region, and a linkage map of the resistance region was constructed. Characterization of the 40 new SSR markers is in progress.

Vermicompost, derived from the processing of organic waste by earthworms, is a beneficial soil amendment known to improve plant and soil health due to the presence of beneficial microorganisms. Vermicompost microbiome can vary radically depending on the starting substrate, environmental conditions, and earthworm species, making it important to characterize the microbial community over time under a variety of vermicomposting conditions. To characterize the microbial community of vermicompost produced from rabbit manure, four samples were collected from vermicomposting bins (Avery Islands, LA) for Nanopore long-read sequencing: one unprocessed manure samples, and samples which had been composting for 1-, 6-, and 12-months. About 135Gb of sequence data with a median quality of Q19 was produced. Relative taxonomic abundance of the microbial community was assessed using Kraken2 and Braken. Manure samples differed in microbiome composition, but were both much less diverse than vermicomposted samples, which had much greater bacterial diversity and were rich in nitrogen-fixing bacteria such as Mesorhizobium and Bradyrhizobium. 1-month old vermicompost more closely resembled 12-month old vermicompost than unprocessed manure, suggesting that a majority of the benefits of vermicomposting are realized within a relatively short period of time.

First They’re Sweet, Then They’re Sour: The Impact of Cultivar, Berry Maturity, and Phytohormones on Blueberry Quality Uniformity - Michael Gasdick
Phytohormone and Plant Growth Regulator Use in Blueberry Production – A Review - Daniel Dick
Postharvest Quality of ‘Calypso’ Blueberry After Hand and Machine Harvest - Wei Yang
Preliminary Findings from the Evaluation of New Cranberry Cultivars in Massachusetts - Giverson Mupambi

Fruit quality parameters are typically reported by growers and researchers as an average. However, for small fruits such as blueberries, berry-to-berry variability in texture and flavor also impacts the consumer eating experience. The objective of this project was to capture how fruit quality uniformity varies by 1) cultivar, 2) berry maturity, and 3) exogenous phytohormone applications. From 2022-2023, analyses were conducted on individual blueberries from multiple studies carried out in commercial fields in Michigan. First, we compared the uniformity of berry weight, diameter, firmness, and total soluble solids in six northern highbush blueberry cultivars: “Duke,’ ‘Bluecrop,’ ‘Draper,’ ‘Calypso,’ ‘Elliott,’ and ‘Aurora.’ Second, we evaluated how changes in berry maturity due to delayed harvest and sequential harvest dates affected the uniformity of berry weight, diameter, firmness, total soluble solids, pH, total acidity, and aroma volatile concentrations in: ‘Duke,’ ‘Draper,’ ‘Calypso,’ and the uniformity of berry weight, diameter, firmness, and total soluble solids in ‘Bluecrop,’ ‘Elliott,’ and ‘Aurora,’ respectively. The implications of delayed harvest on the uniformity of consumer liking scores will also be discussed. Finally, we tested whether exogenous application of multiple phytohormones impacted the uniformity of berry weight, diameter, firmness, and total soluble solids in ‘Bluecrop,’ ‘Elliott,’ and ‘Aurora’. We conclude that “uniformity” is an important component of fruit quality in blueberry.

Plant growth regulators (PGRs) are natural or synthetically derived plant hormones that play a significant role in shaping plant growth and development. In tree fruit and table grape production, PGRs are commonly employed to address production challenges, including modulating crop load and improving fruit size, coloration, and quality. Meanwhile, their use in berry crops such as blueberry remains limited despite the prevalence of production challenges and the availability of registered PGRs for other fruit crops. This review summarizes the existing literature regarding PGR use in blueberry, as well as the current needs for research on PGRs going forward. First, considering the large increase in U.S. blueberry production over the past decade, we highlight the lack of PGRs registered and utilized in blueberry compared to other fruit crops. Second, we summarize the current literature on the utility of PGRs to mitigate challenges in blueberry production, including cold hardiness and frost protection, dormancy release, fruit size and crop load management, fruit quality improvement, post-harvest shelf-life extension. Finally, this work presents future opportunities for research involving PGRs in blueberry production. As blueberry production continues to increase in the U.S. and globally, the need to mitigate production challenges using PGRs will likely also increase.

The 'Calypso' blueberry has emerged as a popular variety widely planted in the Pacific Northwest. Its reputed storage quality and reasonable firmness suggest its suitability for mechanical harvesting in the fresh market using over-the-row machine harvesters. To explore its postharvest quality after both hand and machine harvest, we conducted a comprehensive study in a commercial, 7-year old 'Calypso' field in Oregon. Additionally, a drop test was employed to simulate machine harvesting for fresh market blueberries. Throughout a 4-week period of cold storage, fruit firmness generally remained stable, with occasional increases noted, while berry size remained consistent, indicating 'Calypso' maintains good storage quality. Examination of fruit internal bruise damage (IBD) by cutting berries along the equator revealed consistent levels of IBD throughout cold storage, elucidating why 'Calypso' enjoys a good shelf life. The drop test demonstrated 'Calypso's' resilience to damage from drops, with a similar pattern of fruit IBD development observed between drop-tested and machine-harvested fruits. This study highlights the slow rate of IBD development in 'Calypso' fruit as a crucial factor contributing to its success in machine harvesting for fresh market operations.

Cranberry growers in Massachusetts still rely primarily on heritage cultivars, such as Howes (1843) and ‘Early Black’ (1852). The research aims to increase the profitability and sustainability of the Massachusetts cranberry industry by evaluating twelve new hybrid cultivars for improved yield, fruit quality, disease resistance, and size. The research project was initiated in March 2021 with the prorogation of the new cultivars in a greenhouse. At the same time, the renovation of a 0.75-acre cranberry bog was initiated. The renovation included stripping off the top 0.25 m of the bog and replacing it with new sand. A new irrigation and drainage system was also installed. The new cultivars were planted in June 2021 at the Cranberry Station in East Wareham, Massachusetts. The new cultivars were planted in a randomized, complete block design with four replications per cultivar and buffer zones between the plots. Standard commercial cultural practices for new plantings regarding irrigation, fertilization, pest control, and canopy management were followed. Fruit was removed from the vines to allow maximum resource allocation for canopy growth in 2022, and the first fruit harvest was in 2023. Yield was measured by picking all fruit within a 0.09 m 2 quadrat. The fruit samples were then sieved through an 8-mm opening to remove undersized berries; the remaining berries represented the yield of marketable berries. Additional samples (≈500 g) were collected from each treatment replication for fruit quality analysis. Fruit color was measured using total anthocyanin content (TAcy). Regarding yield, Haines® (353 barrels/acre), Welker™ (287 barrels/acre), and Crimson King (243 barrels/acre) were the most productive, while Vassana® (112 barrels/acre) and HyRed® (117 barrels/acre) performed poorly, with the other cultivars in the mid-range. Scarlet Knight® (81 TAcy), HyRed® (65 TAcy), and Midnight 8 (58 TAcy) had the best fruit color, while Badger (16 TAcy), Granite Red (22 TAcy), Sundance (24 TAcy), and Pilgrim King (26 TAcy) had poor fruit color. The highest fruit rot incidence was observed in HyRed® (37%), Welker™ (52%), and Vassana® (63%), while Granite Red (11%), Mullica Queen® (13%), Badger (18%), and Sundance® (19%) had the lowest incidence. The fruit size measured as fruit diameter was largest in Badger (20.3 mm), Granite Red (20.3 mm), Crimson King (19.8 mm), and Haines® (19.5 mm). In conclusion, first-year harvest data showed differences in the performance of the cultivars under MA growing conditions. Additional data from multiple years are still needed to provide growers with recommendations.

K-IBA Promotes Adventitious Rooting of Bog Birch Stem Cuttings - Jessica Hutchinson
Propagating Pomegranate Through Hardwood and Softwood Cuttings - PRAKRITI NEPAL
Identifying Patterns of Clone Degeneration to Improve Diagnostics - Thomas Gradziel
Evaluating Leaf Cutting Success for Achimenes Propagation - Chad Miller

Native ornamental plants, which are growing in demand in the U.S. horticulture industry, may promote biodiversity and wildlife habitat, and improve landscape resilience. To succeed in the horticulture industry, novel introductions must be aesthetically pleasing and amenable to commercial propagation and production. Bog birch (Betula pumila) is a shrub native to the United States with pubescent, ovate leaves with rounded margins that have tones of red, orange, and burgundy in autumn. In addition, young pubescent stems are brown to reddish-brown and become deep in color with a glossy finish at maturity. These qualities would make bog birch attractive within managed landscapes. We investigated the effects of auxin concentration and wounding during propagation of bog birch by softwood stem cuttings under intermittent mist. Cuttings collected in late July in northern Maine and treated with the potassium salt of indole-3-butyric acid (K-IBA) in solutions of 1,000 to 5,000 mg⋅L-1 produced greater root counts and root ratings, and longer root lengths, than cuttings treated with water alone. Cambial wounding increased root counts modestly, but was unnecessary to produce quality clones. Nearly 75%  of all cuttings produced roots rated 3 or higher, the threshold at which they are transplantable. Only low concentrations of K-IBA are needed to produce root systems that meet this threshold, as transplantability increased from 55% in cuttings treated with water to 73% when 1000 mg⋅L-1 K-IBA was applied. During one season in #1 nursery containers, bog birch propagated from 5 to 6-inch cuttings grew into upright, well-branched plants that were several feet tall, exceeding the total height of many plants we found in the bog environment from which we collected cuttings. Although we found the small, pubescent leaves with rounded margins on wild plants to be a key aesthetic trait, the same genotypes cultivated in containers produced broader leaves with reduced pubescence. Similarly, although plants in the wild often form small clonal colonies, plants in containers for one season were upright shrubs with no obvious colonizing behavior. Future trials to characterize phenotypic variation of plants cultivated in typical horticultural landscapes would help us understand its aesthetic value as a landscape plant. Bog birch is well-suited to clonal propagation and grows vigorously in nursery containers, indicating that it is amenable to commercial production.

Pomegranate (Punica granatum) is a fruit-bearing deciduous shrub or small tree known for its nutritious and medicinal value. Its global demand is high due to rich antioxidant content, health benefits, and culinary versatility. However, the expansion of pomegranate cultivation face challenges due to the need for efficient propagation techniques that can produce high-quality plant material to meet commercial and agricultural demands. The propagation of pomegranate using cuttings is considered an easy and cost-effective method. Hardwood and softwood cuttings were treated with 3000 mg/ L indole-3-butyric acid (Hormodin® 2) and stuck in a rooting medium consisting of perlite and peat moss (4:1, v:v). Hardwood cuttings of 21 pomegranate cultivars, including ‘Al-Sirin-Nar’, ‘Angel Red’, ‘Apseronski’, ‘Arturo Ivey’, ‘Ben Ivey’, ‘Carolina Vernum’, ‘Chiva’, ‘DeAnda’, ‘Early Wonderful’, ‘Kandahar’, ‘Kazake’, ‘Kunduzski’, ‘Larry Ceballos І’, ‘ML’, ‘Mollar’, ‘Purple Heart’, ‘Russian 8’, ‘Salavatski’, ‘Spanish Sweet’, ‘Surh-Anor’ and ‘Wonderful’ were propagated in 2014, 2016, 2018, and 2023. In addition, softwood cuttings of 23 cultivars, which included ‘Al-Sirin-Nar’, ‘Ambrosia’, ‘Apseronski’, ‘Ariana’, ‘Azadi’, ‘Cranberry’, ‘Desertnyi’, ‘Eversweet’, ‘Golden Globe’, ‘Green Globe’, ‘Haku Batan’, ‘Loffani’, ‘Medovji Vahsha’, ‘Molla Nepes’, ‘Palermo’, ‘Parfianka’, ‘Phoenicia’, ‘Purple Heart’, ‘Salavatski’, ‘Sirenevyi’, ‘Surh-Anor’, ‘Vkusnyi’, and ‘Wonderful’ were propagated in 2022. The rooting percentage of hardwood cuttings was higher in ‘AL-Sirin-Nar’, ‘Salavatski’ and ‘Surh-Anor’, whereas ‘DeAnda’ and ‘Early Wonderful’ showed lower rates compared with other cultivars based on cluster analysis. For softwood cuttings, the rooting percentage did not display significant differences across cultivars, however, the number of roots were significantly higher in ‘Cranberry’, ‘Eversweet’, ‘Surh-Anor’ and ‘Wonderful’ compared with ‘Ambrosia’ and ‘Golden Globe’. Further research is needed to identify the most effective propagation technique for pomegranate production.

Plant clones, because they are the product of asexual reproduction, are populations of genetically identical individuals and are important in agriculture, horticulture, and ecology. Although clones can be maintained for hundreds to thousands of years through repeated cycles of vegetative reproduction, degeneration of plant fitness and/or productivity often occurs with increasing age and/or cycles of propagation. While powerful diagnostics allow increasingly accurate identification of the underlying causes for biotic (diseases, pest, etc., and abiotic (nutrient deficiency, inadequate chill, etc.) breakdowns in normal growth and development, genetic/epigenetic failures remain poorly understood, often being generalized as ‘off-types’. A major impediment to the effective deployment of emerging tools for identifying causes of genetic/epigenetic failures is the uncertainty as to where the failure first occurred, which is necessary to identify the most appropriate tissues for testing. Characteristic patterns of clone degeneration can be used to distinguish among different types of failure as well as recommend appropriate methods and tissues for analysis. Clone degeneration from ‘General-aging’ is due to the accumulation of many small-affect deleterious factors making targeted genetic/epigenetic diagnosis difficult though tracking changes in selected methylation profiles could serve as indicators of ‘clone-age’ particularly when ‘slow-to-age’ epicormic meristems are available for reference. ‘Bud-sports’ results from genetic/epigenetic changes in mitotically active cells resulting in distinct sectoral chimeras in subsequent shoot growth and development that can be targeted for molecular and phenotypic analysis. In contrast, ‘epigenetic-imprinting’ seems to be induced at the tissue rather than single cell level making the determination of initial induction time and site difficult to determine. In addition, because most shoot structure in temperate perennials is largely preformed during the previous growing seasons, the time and location between the initial imprinting and its first phenotypic detection can be months to years. Examples, largely from tree crop production, will be presented showing that expression patterns within these major groups can further delineate the specific nature of clone degeneration including the identification of appropriate tissues for testing.

The hot water plant (Achimenes hybrids) is a colorful gesneriad plant and can be
used as potted decorative plants indoors. These impatiens-like plants can also
be used outdoors in mixed containers and in hanging baskets. Increased
commercial production of Achimenes is limited for a couple of reasons.
Achimenes are typically propagated by rhizomes and rhizome production is
limited due to poorly understood plant responses to environmental conditions to
develop rhizomes and subsequent dormancy release. Moreover, rhizomes also
randomly develop on stolons and enlarged roots in growing media, making
harvesting challenging. One alternative method to asexually propagate
Achimenes would be from stem tip cuttings or leaf cuttings. This study
investigated three different Achimenes selections and the effects of bottom heat
and three different rooting hormone concentrations [0; 1,000; and 8,000 ppm
indole-3-butryic acid (IBA)] on root and shoot development on Achimenes leaf
petiole cuttings. Generally, leaf cuttings for all three selections developed more
shoots without bottom heat, although not always significant. All leaf cuttings, for
all selections propagated with and without bottom heat, developed roots and
shoots. The percent leaves developing adventitious shoots were lowest for
leaves treated with bottom heat for 0 and 8,000 ppm IBA in ‘A16’ at 80% and for
8,000 ppm IBA in ‘A23’ at 60%. Root ratings, based on a scale of 0 (no
adventitious roots) to 5 (significant number and length), were significantly higher
across all auxin levels for leaves grown without bottom heat in ‘A16’ and ‘A23’.
This study demonstrated that leaf petiole cuttings for Achimenes can be
successful and result in rooted cuttings producing adventitious shoots, which
could be potentially further propagated.

 The recent loss of our colleague Marc van Iersel reminds us of the reasons our work in horticulture is so important. Marc's career was devoted to developing processes that judiciously utilized sensors to create efficient strategies to optimize crop quality and production for the grower. By examining the path of van Iersel’s work, we can understand how directed, mindful research can move quickly from the hands of the researcher to the farmer. Marc’s early work centered around developing smart irrigation systems utilizing biofeedback to measure soil moisture, with the goal of reducing water usage. More recently, Marc’s work integrated LED lighting with sensors including light sensors, moisture sensors, and low cost canopy and fluorescence detection to generate strategies for precise, energy efficient control of lighting in greenhouse and vertical growing platforms. Marc frequently consulted with growers to understand their needs and challenges, allowing the grower’s needs to frame his research. Marc also mentored the development of students, fellows, and colleagues in their own research, helping them discover how their programs could unfold in directions which would be most valuable. In this session we will examine the history of Marc’s research and continued work by colleagues, to ensure his lessons in how to provide practical answers for commercial horticulture are not lost. This two-hour session will include presentations from Marc's students and colleagues, and conclude with a 30-minute moderated Q&A/discussion.

Coordinator(s)

• Jennifer Boldt, United States Department of Agriculture, Agricultural Research Service, Toledo, OH, United States
• Neil Mattson, Cornell University, Ithaca, New York, United States
• Melanie Yelton, Grow Big, United States

• Bruce Bugbee, Utah State University, Plants, Soils, and Climate, Logan, Utah, United States
  A Life Filled with People, Plants, Photons, and Perseverance (15 mins)
• Stephanie Burnett, University of Maine, School of Food and Agriculture, Orono, Maine, United States
  Impact on Sensor Automated Irrigation and Student Mentoring (15 mins)
• Rhuanito Ferrarezi, University of Georgia, Horticulture, Athens, Georgia, United States
  The Man Behind the Legend (15 mins)
• Andrew Ogden, University of Georgia, Griffin, Georgia, United States
• Shuyang Zhen, Texas A&M University, United States
  The Light He Shined: Translating Plant Physiology into Smart Lighting Control Strategies (15 mins)
• Leonardo Lombardini, University of Georgia, Horticulture, Athens, Georgia, United States
  Honoring Marc's Legacy (15 mins)