Inoculation methods with Azospirillum brasilense in sorghum crop intercropped or not with palisade grass

• Grant number: 23/07020-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2024
• End date: February 28, 2026
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Fernando Shintate Galindo
• Grantee: Thiago de Lima Martins
• Host Institution: Faculdade de Ciências Agrárias e Tecnológicas. Universidade Estadual Paulista (UNESP). Campus de Dracena. Dracena , SP, Brazil

Abstract

The search for strategies to mitigate the negative effects of abiotic stress conditions related to harsh climatic conditions, combined with soils of low fertility and organic matter, common in tropical conditions, such as the West region of São Paulo, has resulted in the development of products that act in the physiological management of plants, increasing the absorption of water and nutrients, in order to promote greater tolerance and plant growth in adverse conditions. Recent research has demonstrated the potential of using the bacteria Azospirillum brasilense with the bias of promoting plant growth, mainly through greater root growth, in addition to a small contribution in the acquisition of nutrients and biological N fixation (BNF), optimizing management of nutrients and plant growth in productive systems. In addition, the sorghum-palisade grass consortium is a technology where the two species are cultivated together, with the objective of producing sorghum grains and straw and brachiaria straw or forage, with undeniable benefits for the sustainability of production, especially if considered the climatic unpredictability, typical of agricultural activity. Although several studies have been conducted in recent years regarding A. brasilense inoculation in several crops, most studies do not focus on the benefits arising from the inoculation forms on sorghum-palisade grass intercropping. Based on the above, the objective of this proposal is to evaluate forms of inoculation with A. brasilense in sorghum intercropped or not with palisade grass, aiming to optimize the growth and development of grain sorghum. The research project will be developed in the municipality of Dracena - SP, in a typical Ultisol with a sandy texture. The experiment will be carried out in an experimental design in randomized blocks with four replications, in a 4 × 2 factorial scheme, containing 8 treatments: 4 forms of inoculation with A. brasilense (control - without inoculation, inoculation in the seeds, in the sowing furrow and in total area at the beginning of the vegetative development of sorghum), with or without consortium with palisade grass (Piatã grass). Leaf chlorophyll index (SPAD), gas exchange parameters, shoot and root dry mass at full flowering and plant height, stem diameter, 100-grain weight, shoot biomass, sorghum grain yield, accumulations of N in shoots and grains at the end of the cycle (harvest time), as well as the agronomic efficiency and apparent N recovery will be evaluated.