NASCIMENTO, E. C. S.; http://lattes.cnpq.br/5025191724626004; NASCIMENTO, Elka Costa Santos.
Resumo:
The cowpea crop has great socioeconomic importance for the Brazilian Northeast, but in this
region, its production is reduced by water scarcity and, whwn irrigated, by the salinity of the
water, and availability of nitrogen to the plant, making it necessary to use of cultivation
strategies, such as the co-inoculation of diazotrophic bacteria and growth-promoting bacteria
in plants, favoring na increase in biological nitrogen fixation (BNF). Thus, the objective of
this work was to evaluate the efficiency of inoculation ans co-inoculation with
Bradyrhizobium ssp. and Azospirillum brasilense in cowpea under salinity. The experiment
was carried out in a greenhouse on campus I of the Federal University of Campina Grande.
The treatments consisted of T1 (without mineral N fertilizer and without inoculant); T2
(fertilized with mineral N and without inoculant); T3 (Bradyrhizobium ssp. inoculation) and
T4 (Bradyrhizobium ssp. and Azospirillum brasilense co-inoculation) submitted to saline
levels of 0.4; 1.9; 3.4; 4.9 and 6.4 dS.m-1. The experimental arrangement was in randomized
blocks, in a 4x5 factorial scheme with five replications, totaling 100 experimental units.
Aspects of growth, production, physiology and nodulation were evaluated. The variables were
submitted to analysis of variance through the statistical software SISVAR and the level of
significance by the Tukey test of means (p < 0.05) for the data obtained in the different
treatments of qualitative nature, while the data of a quantitative nature were submitted to the
regression study. At the threshold salinity level of cowpea, 3.4 dS.m-1, inoculation resulted in
higher production. The increase in the electrical conductivity of irrigation water negatively
affected the nodulation, growth, physiology and production of cowpea of the <corujinha=
variety.