Efeitos de doses crescentes de níquel (Ni²+) sobre a inoculação de Azospirillum brasilense na cultura do milho (Zea mays L.)

Abstract

Rhizobacteria are plant growth promoters. Inoculation of plant seeds cultivated with rhizobacteria can become an excellent alternative to reduce the environmental risks caused by inadequate use of agricultural inputs and even increase crop productivity. Micronutrients are used by plants in small quantities. Their lack, however, can lead to large losses in productivity. The objective of this work was to evaluate the effect of the inoculation of Azospirillum brasilense associated to the application of increasing doses of Nickel (Ni2+) in corn (Pionner 30F53YH variety). The experiment was carried out in a greenhouse at the Federal University of Southern Border - UFFS, Laranjeiras do Sul-Pr Campus. The soil used as substrate was a DISTROFIC RED LATOSOLO and the experimental design adopted was a 2 x 4 factorial scheme in the form of Fully Dilated Design (DIC), being 2 forms of inoculation of corn seeds with Azopirillum brasilense (with and without inoculation) combined with 4 increasing doses of Nickel (Ni2 +) in the form of Nickel Sulphate (NiSO4) incorporated into the soil, totaling 8 treatments. Three treatment-1 replicates were used, totaling 24 experimental units (vessels). Each experimental unit was represented by a polyethylene plastic vessel with capacity of 20 liters, filled with soil. At 55 days after emergence (DAE), 6 maize plants (3 treatment-1 pots) were collected from each treatment tested, which represent the mean of the treatment, to determine the following variables: plant height (AP), diameter leaf dry mass (MSF), stem dry mass (MSC), total aerial dry mass (MSTA) and leaf chlorophyll (CLOR). The data were submitted to analysis of variance (ANOVA) and the means were compared by the Scott-Knott test at the 5% level of significance. Statistically there was no significant difference between the treatments tested for the variables: AP, DC, MSF, MSC, MSTA and CLOR. No interaction or synergism was observed between the rhizobacterium Azospirillum brasilense and the Ni micronutrient for the different variables considered, in relation to the maize crop.