Productive components of ‘Vera’ lettuce grown in soil with application of rhizobacteria and nitrogen

Abstract

In the cultivation of leafy vegetables, alternative inputs are required to reduce the application or enhance the plant uptake of industrial fertilizers used in conventional agricultural production. This work aimed to evaluate the effect of Azospirillum brasilense, Bacillus subtilis, Bradyrhizobium japonicum, and nitrogen applied to the soil in an isolated and combined way on the production components of lettuce cultivar Vera. The experiment was carried out in a greenhouse using a completely randomized design, in a 2 x 2 x 2 x 2 factorial scheme, with five repetitions. The evaluated variables were number of leaves, fresh weight of shoots and dry weight of shoots, root and total as well as nitrogen accumulated in the shoot. The isolated and combined effects produced by Bacillus subtilis were negative for all variables. Conversely, Azospirillum brasilense enhance the fresh weight of the shoot and the number of commercial leaves, and when nitrogen fertilization was carried out in the soil, its combined application with Bradyrhizobium japonicum resulted in a greater accumulation of nitrogen in the shoot, making this rhizobacteria more suitable for both increasing plant growth and enhancing nitrogen uptake by the lettuce.