Nutrition and grain yield of common bean as affected by co-inoculation of Rhizobium tropici and Azospirillum brasilense and application of nitrogen at sowing

• Grant number: 17/04387-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2017
• End date: April 30, 2018
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Adalton Mazetti Fernandes
• Grantee: Rodrigo Alves de Paula
• Host Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Nitrogen (N) is the nutrient required in greatest quantity by the common bean (Phaseolus vulgaris L.). Nitrogen fertilizers used have a high economic and energy costs, and the low efficiency of use by plants, resulting in heavy losses and risk to the environment. Co-inoculation of bacteria of Azospirillum genus with the Rhizobium can be an alternative for the supply of N to the crop because it can stimulate root growth and enhance the nodulation of bean, reducing the need for nitrogen fertilizers. The aim of this study is to evaluate the effect of co-inoculation of Rhizobium tropici and Azospirillum brasilense and N application at sowing on growth, N accumulation and the grain yield of common bean. The research will be conducted in field conditions, in Experimental Farm Lageado, in College of Agricultural Sciences - UNESP, in Botucatu - SP. The design will be in randomized block in a factorial 5 x 2, with four repetitions. Five treatments of co-inoculation and sidedressing N application will be studied [absolute control (without inoculation and without N fertilization); application of 60 kg ha-1 of sidedressing N at V4; inoculation with R. tropici 2.5 x 106 cells seed-1; inoculation with A. brasilense 2.5 x 105 cells seed-1; co-inoculation with R. tropici 2.5 x 106 cells seed-1 + A. brasilense 2.5 x 105 cells seed-1], combined or not with the N application at sowing (20 kg ha-1). In the R6 stage, the bean plants will be assessed for relative chlorophyll index, leaf nutrient concentration, shoot dry matter, and concentration and cumulative amount of N in the shoot. On the occasion of the plant cycle closure will be evaluated yield components, grain yield and protein content in grain. The data will be submitted to analysis of variance. The treatment means are compared by Tukey test at 5% probability. (AU)