Edaphic and Environmental Factors Influencing the Initial Establishment of Sporobolus indicus (Smutgrass).

• Grant number: 25/17640-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2025
• End date: November 30, 2026
• Field of knowledge: Agronomical Sciences - Agronomy
• Principal Investigator: Pedro Luis da Costa Aguiar Alves
• Grantee: João Victor Baptista Lara
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

Sporobolus indicus (capim-capeta) is a weed of high agricultural importance due to its persistence in the soil seed bank, rapid dispersal, and strong competition with commercial crops. Its presence compromises the establishment of cultivated plants, reduces productivity, and increases management costs. However, there are still gaps in our knowledge about the environmental factors that influence the germination and emergence of this species, hindering the development of more efficient control practices. This project aims to investigate the dynamics of germination and emergence of S. indicus under different environmental conditions, considering light, temperature, sowing depth, soil cover, and the effect of water and salt stress. The effects of pH and nutrient availability will also be evaluated. The proposal seeks to generate fundamental knowledge to support integrated management strategies, with a focus on agricultural sustainability. The experiments will be conducted in the laboratory and greenhouse. Germination tests will use light regimes (0 to 24 hours), different temperatures (constant and alternating), as well as polyethylene glycol (PEG 6000) and sodium chloride (NaCl) solutions at osmotic potentials of 0 to -0.8 MPa. For emergence, PVC columns filled with dystrophic Red Latosol soil will be used, evaluating effects at depths of 0 to 10 cm, with and without Marandu grass straw cover.The percentage and rate of germination and emergence will be measured, as well as the visual characterization of non-emerged seedlings. It is expected to identify the optimal and limiting conditions for the establishment of S. indicus, contributing to the formulation of more effective control strategies. The project also includes collaboration with researchers from the University of Georgia (USA), aiming to broaden understanding of the species in different production systems and strengthen internationalization through sandwich internships. (AU)