Rowcover Modifies Microclimatic Conditions and Increased Cilantro Yield in Virginia

Cilantro is grown in Virginia by small farmers for its value as a fresh herb in local markets and is part of their diversified production system. To extend production into the winter, cilantro was grown under rowcover at the Eastern Shore Agricultural Research and Extension Center, Painter, VA, to associate growth with modified microclimatic conditions. Cultivars ‘Calypso’, ‘Leisure’, ‘Marino’, ‘Santo’, and ‘Turbo’ were sown in 19 Sept. 2014. After emergence and weeding, spun-bonded rowcover was installed as a low tunnel over metal hoops in 25 Oct. 2014. Rowcover was not removed until harvest in 19 Dec. 2014, after light freezing events had occurred in the area. Plants that were under the rowcover were still green without symptoms of cold stress in contrast to the uncovered plots that showed leaf reddening in response to freezing temperatures and wind. Differences in temperature, wind chill, evapotranspiration, and soil moisture were recorded between plots with rowcover and without. Yield of harvested foliage under the rowcover averaged 12 ton/acre, 56% higher than without cover. Yield of ‘Calypso’ was less than all other cultivars when grown without rowcover. There were no differences among ‘Leisure’, ‘Marino’, ‘Santo’, and ‘Turbo’. Under rowcover, yield of ‘Marino’ was larger than the other cultivars which were no different among them. In conclusion, spun-bonded rowcover modifies microclimatic conditions and protect against wind and light freezes resulting in improved growing conditions. Therefore, it can increase production and extend the harvest season of cilantro with acceptable quality well into the winter. Among cultivars, ‘Calypso’ underperformed without rowcover in this study. In contrast, ‘Marino’ performed better than the other cultivars under the rowcover, but not without rowcover.