Efeito da variação de níveis de água disponível no solo sobre o crescimento e produção de feijão caupi, vagens e grãos verdes

The effect of different levels of available water in the soil was evaluated on the growth and production of green pod and green beans (Vigna unguiculata (L.) Walp) of cowpea, cv. IPA 206. Both forms of commercialization are excellent alternatives for farmers from the Northeast of Brazil. Plants were cultivated in 13 kg soil pots under green house conditions in Areia, Paraiba State, from August to December/2000. The experimental design was a randomized complete block design with six replications and four treatments corresponding to 40; 60; 80 and 100% of available water in the soil, just after irrigations. The production was significantly affected by the deficit of water. Great reduction was observed in the length of the main stem (26 and 48%), in the number of leaves per plant (23 and 35%), in the number of pods per plant (32 and 49%) and in the mass of pods per plant (23 and 30%), respectively, for the levels of 60 and 40% of available water in the soil. The production of green pod and green beans of cowpea cv. IPA 206 is greatly affected by deficit of water of 40 and 60%.