Seletividade de herbicidas em plantas de trevo vesiculoso

Abstract

The vesicular clover (Trifolium vesiculosum S.) is among the forages that have assumed great importance in pasture based production systems due to their quality, being also that the legumes in general assume great importance for the sustainability of productive systems in Consortium with grasses. However, its slow spread in farming systems is due to the lack of information about the crop. The present study aimed to evaluate the selectivity of post emergent herbicides in different phenological stages of the crop, taking into account that there is no indication or registration of herbicides for the control of weeds in the vesicular clover culture in Brazil. The experiment was carried out in a greenhouse at the Federal University of the Southern Frontier, in the municipality of Cerro Largo, RS, Brazil, in a completely randomized design with four replicates (4 × 4): four herbicides (imazethapyr, metsulfuronmethyl, bentazon, chlorimuron) . Seeding was performed in pots where a population of 10 plants per pot was established. The phytotoxicity index, survival index and dry matter production were evaluated. The survival evaluation was done by counting, the evaluation of phytointoxication through the visual analysis and the dry matter production through the drying and weighing of the aerial biomass. It was observed that there was a significant difference between herbicides, where it was verified that the herbicide bentazon was selective for the crop without harming its development in both phases of application and also that the herbicide imazethapyr can be used but can delay the development of the plant.