Evaluation of Summer Cover Crops Sorghum [Sudangrass Sorghum Bicolor L. (Moench) x Sorghum Sudanense)] and Pigeon Pea (Cajanus cajan L.) Management on Fall Cabbage (Brassica oleracea L. ‘Capitata')

In Haiti and other tropical systems, pigeon pea is a valuable rotational crop. As a first step to evaluate the potential for pigeon pea to be used for multiple purposes in low-external input vegetable systems, this study was conducted to identify the cover crop planting scheme and termination management strategy associated with the greatest cabbage yield and quality when as a rotational cover crop prior to cabbage. The experiment was conducted in Live Oak, Florida at the UF-IFAS North Florida Research and Education Center-Suwannee Valley in 2011 and 2012. Treatments were arranged in a split split-plot design and replicated four times. Main effects included four cover crop (CC) treatments: pigeon pea, (PP); sorghum Sudangrass, (SS); PP and SS biculture (SP); and no cover crop (control). Cover crop plots were equally split in week four after CC emergence with two levels of nitrogen (N): 57 kg ha^-1 or 0 kg ha^-1 (subplots). Each subplot was equally split again prior to cabbage transplanting. Cover crops were mowed and soil-incorporated (CT) or rolled (NT) with a roller-crimper (sub-subplots). Data from cover crop biomass, weed biomass, cabbage yield and yield parameters were analyzed using repeated measures analysis (PROC GLIMMIX, SAS V. 9.3, SAS Institute Inc., Cary, NC) in order to determine main effects of cover crops planting, fertilizer, and tillage management as well as their possible interactions. Tillage approach, rather than cover crop planting scheme was more important to cabbage yield. The greatest cabbage yield and marketable yield were 54 and 38 ton.ha^-1, respectively in fall 2011 and 38 and 17 ton.ha^-1, respectively in fall 2012. Yields obtained in general from CT plots were greater (P≤ 0.05) than NT plots in both years likely due to a greater occurrence of broadleaf weeds in NT treatments.