Experiments planned in Fall-Winter 2018-2019 and initiated this spring at the OARDC in Wooster, OH are now yielding crop-based data. Additional experiments initiated this past week or to be initiated within several weeks will provide additional numbers of potential value to growers. Overall, these experiments are supported by: (a) the USDA-NIFA Specialty Crop Research Initiative (https://nifa.usda.gov/program/specialty-crop-research-initiative-scri), (b) the USDA-NIFA Organic Transitions Program (https://nifa.usda.gov/program/organic-agriculture-program), (c) the USDA-NIFA Potato Breeding Research support program (https://nifa.usda.gov/funding-opportunity/potato-breeding-research), (d) North-central SARE (https://www.northcentralsare.org/), and (e) companies. Along with our collaborators, through these experiments, we look to provide growers and other members of the industry with information they can use beginning immediately, especially when making decisions involving the use of grafted plants, microbe-containing crop biostimulants, reduced-tillage approaches, high tunnels, and/or new potato varieties. Ideally, this information will increase the yield of money on Ohio farms.
Two ongoing experiments will help identify the optimal growing practices when grafted watermelon plants are used. Grafted watermelon plants are showing high potential in- and outside Ohio. However, their wider use has been slowed by their higher cost and the fact that yields from them are not always higher than from standard ungrafted plants. Importantly, an increasing amount of evidence provided by researchers and farmers suggests that growing practices may have to be altered in order to get the best return on investment from grafted watermelon plants. Studies and farmer experience point to changes in plant density, and/or nutrient and/or irrigation management as possibly beneficial. This is reasonable given characteristics of some watermelon rootstocks. So, since 2018, like others, we have been asking if yield can be maintained or increased even as grafted plant density or fertilizer inputs are modified. These two experiments total twelve variety-fertility program and eight variety-plant density treatments. On 8/21/19, the VPSL and OARDC Farm Crew harvested 849 “Jade Star” watermelon fruit from the forty plots spanning roughly 0.7 acre (including pollenizer plants). The 849 fruit totaled 6.2 tons (11 over-filled pallet boxes) and averaged 255 lbs/plot (nine plants). “Fascination” fruit will be taken from the same experiments the week of 8/26, fruit quality will be evaluated in the lab, and the harvest-evaluation process will be repeated for the same experiments to capture total crop yield potential. At the same time, we will continue to focus on: (a) tomato experiments testing grafting, strip-tillage, and/or microbial inoculant effects on fruit yield and quality; (b) butternut squash, carrot (fall high tunnel), and spinach (fall high tunnel) experiments testing microbial inoculant effects on yield and quality; and (c) potato experiments completed in cooperation with breeders at USDA, the University of Maine, Cornell University, and North Carolina State University.