Persistência do picloram em Latossolo Vermelho sob cultivo em curto prazo de variedades de Panicum maximum

Abstract

The agrochemicals market has grown year after year, however, the constant use of these products and the incorrect handling in the application represent environmental risks causing contamination and pollution of soil and water. The objective of this study was to evaluate the persistence of picloram in Red Latosol under short-term cultivation of varieties of Panicum maximum aiming at efficiency in phytoremediation processes. The experiment was carried out in a greenhouse, the design was in randomized blocks, factorial 4 x 3, being four substrates (without cultivation, cv. Mombaça, cv. Quenia, cv. Massai), three doses of picloram (triethanolamine salt) in doses 0, 2, 4 L. ha-1, with four replications, using soybeans (Glycine max cultivar TMG 4182) as bioindicator. The P. maximum cultivars were sown in sand trays and 10 days after emergence the transplant was carried out, leaving three plants per pot, kept for 50 days. After this stage, the soybean transplant was carried out, when they were in stage V1, leaving nine plants per pot. The variables evaluated in soybean plants were visual phytointoxication (SBCPD, 1995), average plant height (cm), the Soil Plant Analysis Development (SPAD) index, fresh biomass - BMF (g) of the aerial part, fresh biomass - BFS (g) from the root, dry biomass - BMS (g) from the aerial part and dry biomass - BMS (g) from the root. The varieties of Panicum maximum were not able to remedy the herbicide in the soil in the short period studied, as soybean plants did not survive contact with the herbicide. The presence of the herbicide was indicated by soybeans even after 90 days of spraying.