This project was conducted to test practical methods for extending the production of cool season leafy greens into the hot summer months in Kansas City, where high temperatures normally terminate production of these crops from June through August. We used high tunnels covered with 40% shade cloth, combined with drip irrigation and were able to produce crops of lettuce (10 cultivars) and Asian greens (5 types) throughout the summer. Trials were conducted at three locations, two of them working organic farms, and the other an agricultural experiment station in order to produce statistically valid experimental results. We produced higher yields of marketable quality lettuce and greens over multiple harvests throughout the summer compared to outside plots, which produced lower yields of poorer quality crops. As a result of this project, both growers have continued with summer greens production, recognizing that adapted warm-season vegetables may be more profitable under hot summer conditions. Results of the project have been disseminated through multiple avenues including workshops at the Great Plains Vegetable Growers Conference in January 2002, and a high tunnel construction guide posted on www.hightunnels.org. A video documenting the research project has been developed funded by a subsequent grant from the USDA SARE program (attached) and will also be posted on the high tunnels website. This project contributed significantly to the initiation of a multi-state USDA-funded project on high tunnels for the central Great Plains, which includes a significant component of research and extension related to organic vegetable production and continuing assessment of extension of cool season crop production into to the hot summer months.
