Crescimento e fisiologia do milho (Zea mays) inoculado com Azospirillum brasiliense irrigado com água salina. com água salina

Abstract

Due to the diverse climatic changes and, mainly of the region in which the culture is submitted, salinity has been an increasingly common problem in world agriculture, thus limiting agricultural production. To deal with such problems, many studies on products to reduce the harmful effect of salinity are being carried out, as well as the alternative of inoculants, which today, has been essential in the fight against this problem. The objective of this work was to observe and evaluate the growth and physiology of corn when inoculated with the bacterium Azospirillum brasilense and irrigated with saline water, thus, correlating the activity of this inoculant to the increase of the plant's capacity to tolerate saline stresses. The experiment was carried out in a greenhouse located on campus I of the Federal University of Campina Grande - UFCG. The corn cultivar used in the experiment was NS-92 VT PRO, being inoculated and sown on the same day. The experimental design used was the DIC in a 2x5 factorial scheme, with 5 repetitions, totaling 50 experimental units. Composed of 2 treatments, presence and absence of inoculant combined with five saline levels of irrigation CEa (0.4; 1.1; 1.8; 2.5; 3.2 dS m-1). Growth evaluations were carried out at 31 DAS, including: Plant height (AP); Stem Diameter (DC); Number of sheets (NF); Leaf area (AF). The physiological evaluations were made at 69 DAS, in which the following were evaluated: Internal CO2 concentration (Ci); CO2 assimilation rate (A); Sweating (E); Stomatal conductance (gs). The data obtained were evaluated by analysis of variance and regression, and the means compared by the Tukey test at 5% significance. The effect of salinity resulted in a decrease in growth and physiological variables. The inoculant, on the other hand, showed significant results in relation to plant height, internal CO2 concentration and transpiration.