Agronomic Performance Of Cowpea [Vigna Unguiculata (L.) Walp.] Cultivars In Different Sowing Dates.

In Brazil, the cowpea crop has significant social and economic importance as food supply, in the keeping people in the field and as a component of agricultural production. The cowpea crop it is becoming an option for producers, for more tolerance to hydric stress, short cycle and less production cost, with growing expansion in the Midwest and Southeast regions of Brazil for cultivation in the second season (out-of-season). However, there are a few information about this cowpea crop in the São Paulo state. The objective of this study was to evaluate the performance of five cultivars, at six seeding dates,during second season. The experiment was conducted in Botucatu, São Paulo State, Southeastern Brazil. The experimental design was a randomized block with split plot scheme and four replications. Each plot consisted of six sowing dates (first and second half of February, March, and April) and subplots by cowpea cultivars (BRS Guariba, BRS Novaera, BRS Cauamé, BRS Xiquexique and BRS Potengi). Were evaluated: shoot dry matter; main branch length; number of lateral  branches; pod length, number of pods per plant,number of seeds per pod, 100-grain mass and grain yield. The best time for sowing of cowpea in the second season is the first half of February until the first half of March and the highest yield of grain were observed in BRS Novaera, BRS Cauamé and BRS Potengi cultivars. The delayed sowing, cause delay in flowering and prolonging the cycle, lower plant development and reduction of grain yield in all cowpea cultivars.