Yield of maize hybrids: Is there any association among nitrogen rate, Azospirillum inoculation and fungicide treatment?

Optimization of land use can be attained by incorporating technologies to crop production, such as the use of diazotrophic bacteria, fertilizers, and pesticides. Seed inoculation with Azospirillum is an alternative that favors the incorporation of green agriculture in regions of conventional farming, such as the Brazilian savannah (Cerrado). However, limited information is available about this bacterium’s contribution to agriculture when other technologies are also incorporated. This study evaluated the performance of maize hybrids inoculated, or not, with Azospirillum brasilense, with or without fungicide applications, and subjected to different nitrogen rates under Cerrado field conditions. Each factor analyzed contributes to the increased maize grain yield. The use of inoculants containing plant growth promoting bacteria is a good option to ensure high yield of maize. Still, nitrogen should not be replaced, neither totally nor partially, by seed inoculation with Azospirillum. Fungicide applications should be done, as required, during maize cycle. Moreover, specific maize breeding programs should consider the affinity between Azospirillum strains and maize hybrids, mainly for regions with nitrogen deficient soils, like Cerrado. Thus, by incorporating additional technologies, maize crop farmers can optimize land use and, consequently, reduce the expansion into new agricultural areas. Key words: Foliar protection, nitrogen use, plant growth promoting bacteria, sustainability, Zea mays L.