Hoop House and Open Field Organic Tomato Trials for Production and Quality Characteristics in the Upper Midwest

Tomato (Solanum lycopersicum) is a key crop for diversified organic vegetable growers. Farmers selling in local markets can often charge a premium for high quality organic tomatoes. Heirloom tomatoes are prized for their flavor, but may be low-yielding and susceptible to splitting and disease. Tomatoes bred for high yield, disease resistance, and uniform ripening often lack fresh-eating quality. Combining superior quality with productivity and regional adaptation are important priorities. In addition, hoop houses have gained popularity in recent years as tools for extending the tomato season by as much as two months, and potentially obtaining higher yields and higher quality than from field-grown tomatoes. In 2014 and 2015, a total of 60 tomato varieties (40 per year with 20 varieties trialled in both years), were grown in a hoop house and an adjacent field, all under organic management, at the West Madison Agricultural Research Station in Wisconsin. Varieties were chosen for evaluation based on private and public-sector tomato breeder recommendations for good performance in organic systems and good fresh eating quality. Heirlooms, modern open pollinated varieties and modern heirlooms and new breeding populations were included. Varieties were evaluated for total marketable yield by weight and fruit number, average fruit weight, unmarketable yield by weight, percent unmarketable yield, disease resistance, earliness, and sugar and acid content. Marketable yield in the hoop house was 20% higher than the field in 2014, and 45% higher in 2015. Heirloom yield did not differ from modern varieties in the hoop house in 2014 but was significantly lower in the field both years and slightly lower in the hoop house in 2015. Management system (hoop house vs. field) had a larger contribution than variety to the variation for marketable yield. The percent unmarketable fruit was not different between field and hoop house, although there were different principle causes between management systems. Foliar disease was much more severe in the field than in the hoop house. The Brix was higher in the hoop house than in the field, and titrateable acidity was the same between the two management systems. For these two traits, variety had a greater contribution to the variation than management system. Flavor evaluations by local chefs have helped characterize promising varieties for culinary quality. Based on these results, we have identified productive and high quality varieties and breeding lines for further selection in the upper Midwest.