(415) Evaluation of Weed Control Practices in an Organic Bell Pepper Production System

A 2-yearfield study in Lexington, Ky., evaluated the use of mulches in two organic production systems for bell peppers. Two planting strategies, flat ground and plastic-covered raised beds, and five weed control practices, straw mulch, compost mulch, wood chip mulch, corn gluten, and “living mulch” clover were tested. In 2003, the mulches were applied at planting, while in 2004, shallow soil cultivation was used for 6 weeks prior to mulch application. In 2003, the experimental field had been under a winter wheat cover crop; in 2004, the field had been cover cropped for more than a year prior to planting with sudex/cowpea (Summer 2003) and rye/hairy vetch (Winter/Spring 2004). Bell pepper yields in both bed treatments were very low in 2003 due to extensive weed competition. In 2004, plastic-covered raised beds coupled with mulching in-between beds resulted in significantly higher yields than the peppers grown on flat ground. These yields were as high as yields from a conventional pepper trial conducted on the same farm. Compost mulch, continuous cultivation, and wood chip mulch provided excellent weed control in 2004. Straw mulch was variable in its weed control efficacy; corn gluten and “living mulch” clover were ineffective.