Efeitos fisiológicos e metabólicos de subdoses de glyphosate e da adubação fosfatada em eucalipto

• Autor(a) principal: Oliveira, Artur Rodrigues
• Data de Publicação: 2021
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/213777
• topic: Glyphosate; Eucalipto; Fósforo

Eucalyptus is the main forest crop grown in Brazil. Chemical control, using glyphosate herbicide, is one of the main ways used in the management of weeds. Glyphosate is absorbed through phosphate carriers and, therefore, competes with phosphate ions at the time of active absorption. The objective was to evaluate the effect of phosphate fertilization and glyphosate application on young eucalyptus plants. The experiment was carried out in a completely randomized design, with five replications. The 2x2 factorial scheme was adopted, being: two types of fertilization (planting fertilization with 1.5 g of formulation 20-0-20 plus 0.7 g of triple superphosphate) and planting fertilization enriched with phosphorus (1.5 g formulation 20-0-20 plus 5.0 g triple superphosphate); and two doses of glyphosate (0 and 72 g a.a. ha-1). Fertilization was carried out with the transplant of the seedlings. The herbicide was applied 30 days after transplanting the seedlings, with a CO2 sprayer pressurized with CO2, with a pressure of 200 Kpa, equipped with a spray bar with four nozzles with tips like TeeJet 110.02 and calibrated for a 200 L há-1 spray volume. Plant height, stem diameter, dry matter and leaf phosphorus contente, were determined at 0, 2, 4, 7 and 192 (except phosphorus content) days after application (DAA). There was no interaction between phosphate fertilization and glyphosate application. The application of the herbicide did not influence plant growth, stem diameter and dry matter accumulation in the aerial part of the eucalyptus. The application of triple superphosphate influenced the phosphorus content in the leaves at 4 and 7 DAA, with a higher phosphorus content in the leaves in eucalyptus plants submitted to complementary phosphorus fertilization. Therefore, there was no interactive effect between phosphate fertilization and application of glyphosate (simulating drift) on growth and phosphorus content in eucalyptus plants. Plants subjected to glyphosate application showed a higher concentration of shikimic acid at 4 and 7 DAA, regardless of the type of fertilization. In all analyzed cases, AMPA was not detected; in the conditions of fertilization and application of glyphosate there was no influence on the concentrations of phenylalanine, tyrosine and tryptophan in the leaves of eucalyptus, except at 2 DAA where there was an influence of glyphosate on the concentration of these amino acids.