Processing tomato (Lycopersicon esculentum Mill.) producers in the Great Lakes region have expressed interest in cutting crop establishment costs and improving profitability by reducing plant populations. This study compared plant development, fruit set, fruit size and yields using a range of single and twin-row plant populations (14,800 to 44,500 plants/ha) and four commercially important processing tomato cultivars (`OH8245', `H9036', `PS696', and `H7135') with differing vine types and maturities. The 3-year study was conducted at Fremont, Ohio, on a Colwood fine sandy loam, using raised beds and other standard cultural practices. Six- to seven-week-old transplants (288 cell size) were mechanically planted in middle to late May. Once-over harvest was timed to achieve 80%–90% red fruit, using a Johnson tomato harvester. Plant population had a significant effect on 1995 fruit yields for all cultivars tested. Optimum red fruit yields were observed at 37,100 plants/ha in twin-rows for `OH8245', which was similar to 1994 results. Optimum fruit yields for `PS696' were obtained at twin-row populations of 29,600-44,500 plants/ha in 1995. Three year results for `OH8245' (medium-sized vine) indicate no significant differences due to plant population or arrangement. Mean red fruit yields varied considerably by year in this field research (62.7, 95.2, and 44.8 MT/ha in 1993, 1994, 1995 respectively), but twin-row spacing of `OH8245' provided significant yield gains in 2 of 3 years for populations of 29,600 plants/ha or greater.
Mark A. Bennett and Elaine M. Grassbaugh
Mark A. Bennett, David M. Francis, and Elaine M. Grassbaugh
Ethephon (2-chloroethyl phosphonic acid) has been widely used under field conditions as a growth regulator to trigger the ripening of processing tomatoes prior to mechanical harvesting. Recent interest in whole-peeled and diced tomato products has raised questions about ethephon rates, and possible split applications for top quality. This 3-year field study tested two commercial cultivars of processing tomatoes (`OH8245' and `P696') and the effect of various ethephon applications on fruit firmness, color uniformity, and peeling variables. Transplants were established in mid to late May of 1996–1998 on raised beds in single rows at the OSU/OARDC Veg. Crops Branch in Fremont, Ohio. Ethrel applications for each cultivar were: 0, 0.58, 0.58 × 2 applications, 1.17, 1.17 × 2 applications, 1.75, 2.34, 4.68, and 7.02 L·ha–1. Fruit were tested for firmness, color uniformity, pH, titratable acids, and soluble solids. Samples from ethephon treatments of 0, 1.17 × 2 applications, 2.34, 4.68, and 7.02 L·ha–1 were peeled and canned for color inspection and firmness after 18 months storage. Three-year data for red fruit yield showed a typical response to increasing amounts (0 to 7.0 L·ha–1) of applied ethephon. While high rates (4.7 or 7.0 L·ha–1) gave some of the highest red fruit yields, and the greatest percent red fruit values, high rates were also linked with among the lowest fruit solids values. Split application comparisons showed little influence on quality variables examined in this study. However, chroma values were improved (more vivid color) when 2.3 L·ha–1 was applied vs. 1.17 L·ha–1 applied twice. Split applications also tended to produce softer fruit. Our results suggest that single ethephon applications of 1.17 to 2.34 L·ha–1 provide optimal fruit ripening and quality under midwestern U.S. conditions.
Elaine M. Grassbaugh, Mark A. Bennett, Mark Schmittgen, and Brad Bergefurd
Specialty vegetables are defined as crops that are different in color, size, shape or nutrient content for that particular crop, those not normally grown in a specific area, or crops grown out of season. Knowing the clientele and what they demand is the first step in successfully marketing these less common crops. Due to market demand, “uncommon” crops are more frequently requested by produce buyers and the public. What is in demand one year may not be marketable the next. Our attempts to produce >25 specialty crops under Ohio growing conditions over the past 3 years resulted in successes and failures. Regardless of the outcome, our findings were important to vegetable growers who are interested in producing these crops. Crops tested from 1994 to 1996 included globe artichokes, luffa gourds, chili peppers, habanero peppers, okra, tomatillos, baby corn, and several specialty tomato varieties. Crops produced successfully in Ohio were marketed through several farm markets, food terminals, and produce brokers. A summary of cultural practices, production tips, and marketing opportunities on these less common vegetable crops based on our research in Ohio will be presented.
Elaine M. Grassbaugh, Mark A. Bennett, Thom Harker, and Mark Schmittgen
The specialty vegetable market is a rapidly expanding niche in the produce industry. One popular sector of this market is focused on heirloom tomatoes. Heirloom varieties, mostly open-pollinated, are often favored for their taste and unique shapes and colors. Older, traditional varieties have been maintained mostly by home gardeners, seed saver organizations, and government germplasm centers, but are becoming increasingly popular with commercial growers, consumers, and seed companies. Special growing techniques and attention to postharvest handling is also necessary with heirloom tomatoes because most do not have an extended shelf life. For growers willing to develop special harvesting and handling techniques, specialty tomatoes offer colors, shapes, and flavors that are an important part of today's cuisine. Performance of a given cultivar will vary from year to year depending on several factors: planting date, irrigation, disease pressure, staking practices, and climatic conditions during the growing season. Fourteen heirloom tomato cultivars have been researched at Ohio State Univ. (OSU) since 1995. Data collected on yield, fruit characteristics, market outlets, cultural information, special harvesting and handling requirements, and disease pressure for heirloom cultivars will be presented.
Elaine M. Grassbaugh, Mark A. Bennett, and Andrew F. Evans
Successful crop production and optimum yields, regardless of the species, can be accomplished only when maximum stand establishment is achieved. Stand reduction after planting typically results in reduced yields and lower crop quality. Several classes of factors (environmental, edaphic, biotic) contribute to successful stand establishment in crop production and should be considered in growing medicinal plants. Environmental factors (e.g., temperature and moisture extremes) as well as pathogens and insect pests that attack seeds and seedlings may contribute to reduced stands. Soil related factors such as pH, nutrient availability, and crusting may also restrict seedling growth. Understanding the requirements for optimum seed germination and the environmental conditions into which the seed is sown is essential for uniform crop establishment. Vigor tests can aid growers in determining the optimum temperature range for seed germination. Many cultural practices may also influence soil related factors and contribute to successful stand establishment in the field. Seed vigor tests (SSAA, thermogradient results) along with seed treatments and enhancements can assess seed vigor, improve germination and lead to more reliable stands of medicinal species.