Sowing Dates for Cowpea Cultivars [Vigna Unguiculata (L.) Walp.] On off-Season.

The cowpea [Vigna unguiculata L. Walp.] is becoming an option for producers in different regions of Brazil, because tolerance to water stress, short cycle and lower production cost. The cowpea has increased expansion in the central region, however, there are not an informations and research on cowpea for the Southeast region. The objective of this study was to evaluate the performance of five cultivars (BRS Guariba, BRS Novaera, Tumucumaque BRS, BRS Cauamé and BRS Itaim), in four sowing dates, during fall-winter (out-of-season).  The experiment was conducted in Botucatu, São Paulo State, Southeastern Brazil. The experimental design was a randomized block in split plot scheme and four replications. Each plot consisted of four sowing dates (second half of February, the first and second half of March and first half of April) and subplots composed by cowpea cultivars. Were evaluated: dry matter of aerial part, nodes  number in the main branch, main branch length, Lateral branches number, height of first pod, pod length, number  pods per plant, number of grains per pod , 100-grain mass and grain yields. The best time for sowing of cowpea is the first the first half of March and in BRS Novaera, BRS Cauamé and BRS Tumucumaque cultivars were observed highest yields.  In all cowpea cultivars evaluated, lower temperatures, from May, as well as lack of rain, promoted delay in flowering and prolongation of cycle.