A Comparison of Tillage and Mulching Strategies for Weed Management in Organic Pepper (Capsicum annum L. ‘Tormenta').

In 2012-2015, teams from the Universities of Virgin Islands, Puerto Rico, and Florida initiated field trails to facilitate the adoption of cover crops and soil conservation practices in cropping systems among farmers in the tropics and subtropics. At the University of Florida/IFAS Suwannee Valley Agricultural Extension Center in Live Oak, a two-year trial was conducted on certified organic land to evaluate the weed suppressive ability of cover crop residue compared to plastic mulch in jalapeno pepper (Capsicum annum L. ‘Tormenta’). A cover crop of sunn hemp (Crotalaria juncea L.) was seeded 85 days prior to pepper on the entire experimental area and terminated late July and early August in 2013 and 2014, respectively. Four treatments were arranged in a randomized complete block design split with two weed removal frequencies, and replicated four times. Treatments included: 1) sunn hemp terminated with a roller-crimper (RC), 2) sunn hemp mowed and incorporated followed by an application of rye straw residue (MI+straw), 3) sunn hemp MI followed by the application of white on black plastic mulch (MI+plastic) and 4) sunn hemp mowed and incorporated without surface mulch  served as a check plot (MI+none). Above-ground dry weight of sunn hemp at termination was 8,960 kg ha^-1 in 2013 and 6,704 kg ha^-1 in 2014.  Above ground dry weed biomass sampled prior to cover crop termination was negligible in 2013, but in 2014, monocot weed dry weight biomass was 346 kg ha^-1 and dicot biomass was 62 kg ha^-1. Following treatment establishment, standard fertilizer and irrigation practices were used in accordance with UF/IFAS recommendations. Weed suppression six weeks after transplanting was similar among MI+plastic, MI+straw and RC, and more effective than MI+none. Seasonal low frequency weeding was frequently as effective as weekly weed removal events, and may be economically beneficial. Pepper yield was greatest in the MI+straw system in 2013.