Evaluation of Cornell Cultivar Performance in Kentucky

Evaluation of Cornell cultivar performance in Kentucky The University of Kentucky is participating as a regional location for the evaluation of new hemp cultivars developed at Cornell University. This project is part of a long-term effort to develop regionally adapted hemp cultivars for growers in the U.S. Small plot trials – repeated in all three years Seed will be provided by Cornell for two experimental hemp cultivars: GVA-H-21-1135, a grain/dual purpose type and GVA-H-22-1061, a fiber type. Seeds will be planted at 15 seeds per square foot for GVA-H-21-1135 and at 30 seeds per square foot for GVA-H-22-1061. Planting de doen with a Great plains 3P0606NT cone drill at 0.5-0.8 inch depth into a chemically killed wheat cover crop at 7.5 inch row spacing. Irrigation will be available if needed for plot establishment and growth under excessive dry conditions. Conventional best management practices will be utilized, including weed control using compatible herbicides such as Sonalan 10G, optimum fertilizer amendment (150 lbs N per acre and P & K according to soil test recommendations (utilizing recommendations for corn). P and K will be applied preplant and N will be applied 10 to 14 days after seeding. Measurements will include stand counts after establishment (14 days), and then growth measurements that can be used in variety description for AOSCA Variety Review, Plant Variety Protection, and/or plant patent applications. Those will include the following vegetative measurements: leaf dimensions, internode length, stem color, leaf color, days to male and female flowering, biweekly height measurements, proportion of branching, stem grooves, male flower color, calyx hairs, and proportion of off-types in the population. Regulatory sampling for THC content will be conducted no more than 30 days before harvest in each replicated plot at each site. Incidence of disease will be surveyed multiple times during the season in the KY. Cannabinoid analysis will be conducted at Cornell in the lab of co-PI Rose. For GVA-H-22-1061, retted straw weight will be the primary yield measurement – no grain yield will be determined. When male plants have flowered and female flowers are just emerging (no senescence of male plants yet), the stalks should be cut just above ground level from the entire plot (5.6’ x 15’) using handheld hedge trimmer. Plant population, stalk heights, and stalk diameters at the base of the stem are additional data that should be collected. Cut stems can be loosely bundled and field retted for 3 to 4 weeks depending on conditions. They should be rotated at least once to encourage proper retting of the entire stem. Once retted to brown/dark brown, but not black color, the retted straw from the entire plot should be weighed. A ~1 kg subsample of the retted stems from each plot should be oven dried to determine retted straw dry weight. The retted stems will be decorticated to determine the bast:hurd ratio. Ground stem material will be submitted for elemental analysis, including heavy metals. For GVA-H-21-1135, grain will be hand harvested and stems will be cut and retted to determine retted straw yield. Grain will be harvested when the seed heads contain ~75% brown mature seed. For grain harvest, stalks will be cut at the base of the flower using pruners from the entire (5.6’ x 15’) plots. Harvested grain heads will be placed in paper bags and air-dried in a protected shed/barn or room with fans and dehumidifiers. After grain heads have been removed, the stems will be cut just above ground level from the entire plot (5.6’ x 15’) using handheld hedge trimmer. Plant population, stalk heights, and stalk diameters at the base of the stem are additional data that will be collected. Cut stems will be loosely bundled and field retted for 3 to 4 weeks, weighed and subsamples collected from each plot and oven dried to determine straw moisture content as described above. Once heads have air dried, grain can be threshed from harvested flowers by hand or small bundle thresher and subsequently cleaned by manual screening or seed blower to obtain grain yields. Moisture content should be determined and yield standardized to 8% moisture content. Dried grain samples will be sent to Cornell to collect additional grain quality assessments, including seed size and shape, seed color, protein content, oil content, and thousand kernel weight. Stems will be cut and retted, then retted straw weight will be determined for each plot. The retted stems will be decorticated to determine the bast:hurd ratio. Strip trials or additional sites – years 2 and 3 It is expected that additional seed will be available for trials in years two and three, which can include seed drilled and mechanically harvested strip trials and/or small plot trials on additional sites in Kentucky to evaluate genotype-by-environment interactions on different soil types. If sufficient seed is available, we would include these cultivars in trials to determine the seedling vigor and root development characteristics relative to other hemp grain and fiber cultivars.