Vegetable Yields and Nutritional Contents In Season Extension Systems

Funded by a Wyoming Department of Agriculture Specialty Crops Program Block Grant, this project’s objective was to evaluate three production methods, including two season-extension systems, for yield and nutritional content using peppers, tomatoes, and eggplants. Crops were grown during the 2009 and 2010 growing seasons at the University of Wyoming’s Sheridan Research and Extension Center. In 2009, ‘King of the North’ and ‘Purple Beauty’ peppers, ‘Rutgers’ and ‘Cosmonaut’ tomatoes, and ‘Black’ and ‘Turkish Orange’ eggplants were grown in the field, under row covers, and in a high tunnel. In 2010, the same cultivars of tomatoes and eggplants were grown, but peppers were ‘King Crimson’ and ‘California Wonder Orange’. Yield data included total weight of fruit produced in each growing situation per five plants. Fruits were sent to the Small Molecules Analysis Laboratory at the University of Nebraska – Lincoln. They were analyzed for total phenols, total flavonoids, and oxygen radical absorbance capacity (ORDC, a measure of antioxidant activity). In 2009, pepper yields were highest under row cover, tomato yields were highest in the field, and eggplant yields were highest in the high tunnel. In 2010, highest yields of both peppers and tomatoes occurred in the high tunnel. Yields of eggplants varied with location and cultivar. Levels of total phenols and flavonoids both years varied depending on cultivar and growing situation. In 2009, ‘Purple Beauty’ peppers showed generally higher phenols, flavonoids, and ORDC than ‘King of the North’ in all three growing conditions, with the exception of field-grown ‘King of the North’ which showed higher ORDC levels. Both tomatoes and eggplants grown in 2009 showed highest phenols and flavonoids when grown in the field but ORDC levels were highest under row covers. In 2010, all pepper nutritional data were inconsistent as were tomato and eggplants phenols and flavonoids contents. Tomato ORDC levels were highest in the field. Eggplant ORDC levels were highest in field-grown fruit in 2010.