ASHS 2015 Annual Conference

Under sub-tropical climate, Miami–Dade County is an ideal place in the United States to produce winter fresh market vegetables in open field. For instance, with more than 11,000 acres a year, it is ranked as No. 1 County in the United States for producing snap beans. However, the major challenge for local growers is pest control because of the favorable weather that makes all pests live year round and creates a lot of pressure for producers. Appropriate cropping system, including growing cover crops and implementing crop rotation, plays a critical role that can break up the food chain and life cycles of pests. Field trials have demonstrated that among all tested summer cover crops, sunn hemp (Crotalaria juncea L. cv. Tropic sun) can grow vigorously during the rainy summer, cover the land quickly and perfectly, and produce a large amount of biomass in two or three months. More important, sunn hemp can suppress soil root-knot nematodes via secreting some nematicides through its roots and decomposition of residues. Therefore, growing cover crop—sunn hemp during the summer season and rotating with valuable vegetable crops in the winter has become a promising cropping system.