Evaluation of row covers for yield performance of the leafy green vegetables in organic management system

Row covers are gaining interest in crop production for their potential to protect crops from insect pests, frost, increase soil as well as air temperature, and extend growing season, thus producing higher crop yield. However, research on the performance of green leafy vegetables grown under row cover in organic management system is scarce. This paper reports result of field trials conducted on the growth and yield responses of leafy greens in row covers grown in organic production system at the Tennessee State University organic farm. Performance of three row covers, including insect net, Agribon cloth, and plastic, was evaluated relative to control (without row cover) in four leafy greens; lettuce, kale, swiss chard, and collard in spring 2018 and 2019 seasons and data were collected on soil temperature, insect damage, plant height, leaf number, and fresh weight. Results showed that fresh weight per plant significantly ( P < 0.05) increased under Agribon cloth in kale, swiss chard, and collard, while lettuce produced significantly higher yield under insect net relative to control (open) in 2018 research trial. In 2019, there were significantly ( P < 0.05) higher fresh weight per plant of swiss chard and collard under plastic, while lettuce produced significantly higher under Agribon cloth and kale under insect net compared with control. These results suggested that row covers enhanced crop yields due to increased plant growth associated with reduced insect damage and favorable microclimate. Thus, row covers is a viable option in sustainable production of leafy greens for organic vegetable growers.