Eficiência agronômica de inoculantes em feijão-caupi no município de Pombal – PB.

Abstract

Cowpea bean [v[0na uniu/cu/afa (L.) Wa]p.] is an exce]lent source of protein, constituting the staple food for low-income populations in the Brazilian northeastern. The interaction of cowpea bean with the fixing bacteria N2 atmospheric, can allow the increase of income of the culture and to supply it with the N needed for its growth and development. In this way, was aimed with this study to evaluate the efflciency of inoculation on cowpea bean in the municipal of Pombal- PB, compared to the utilization of nitrogen fertilizers and the efficiency of populations of bacteria that are able to modulate the cowpea bean, native from the region. For this, the experiment was conducted from September to November of 2009 in the Monte Alegre property, at a distante of about 4 km from the city center of Pombas. It was accomplished in soil that had not been cultivated with cowpea bean yet, and without the utilization of any other inoculants before. Using the cultivar of cowpea bean "New Age", whose seeds were obtained from the EMATER -- Pombal. The experiment was a randomized block design with four repetitions and six treatments, namely: Four treatments with inoculated seeds with strains UFLA 03-84, INPA 1 1 B-03, BR3267 and UFLA 03-154 (42c8), and two not inoculated, one with mineral nitrogen at a dose of 70 kg ha of N (ammonium sulfate) and another without mineral nitrogen. Variables were evaluated for nodulation and agronomia traits of cowpea beans. All tested inoculants had the number and fresh weight of nodules, and the productions of the fitomassa matched to the treatment that received nitrogenous fertilizer, with focus on the strain inoculate UFLA 03-154 (42c8). Thus, the strains have the potential to be used as inoculants in cowpea bean. The populations of bacteria that are able to modulate cowpea bean, native from the área of the experiment, measured values of the number and fresh weight of nodules equal to other treatments, di#ering only with lower values of the inoculant strain, UFLA 03-154 (42c8 ), but in relation to fitomassa production was lower than all other treatments, which highlights its inefficiency.