ASHS 2015 Annual Conference

In 2012, 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 among farmers in the tropics and subtropics. At the University of Florida/IFAS Suwannee Valley Agricultural Education Center in Live Oak, the first year of a two-year trial was conducted on certified organic land to evaluate the weed suppressive ability of cover crop residue compared to plastic mulch. A cover crop of sunn hemp (Crotalaria juncea L.) was seeded 85 days prior to pepper on the entire experimental area and terminated July 12, 2013. Treatments were arranged in a randomized complete block design split with two weed removal frequencies, and replicated four times. Treatments included: sunn hemp terminated with a roller-crimper (RC), sunn hemp mowed and incorporated followed by an application of rye straw residue (MI+straw), sunn hemp MI followed by the application of white on black plastic mulch (MI+plastic) and sunn hemp MI and left without mulch to serve as a check plot (MI+none). Dry granular fertilizer (3-2-2) was applied by hand at a rate of 125 lb/acre (63.5 kg/ha) nitrogen (7.25 lb per bed) in two bands, and except for RC plots, was lightly incorporated with a roto tiller. The balance of recommended nitrogen was applied weekly via fertigation using an organic-compliant fertilizer (4-1-1) following transplant establishment. Drip tape was installed in all plots. Peppers were transplanted July 27. Weed frequency split (every week or every third week) was initiated six weeks after transplanting so that sufficient data could be obtained on the weed suppressive capabilities of the treatments during the critical weed-free period.