SELETIVIDADE DE HERBICIDAS PRÉ-EMERGENTE EM SOJA CULTIVADA EM SOLOS COM CARACTERÍSTICAS FÍSICO-QUÍMICAS DISTINTAS

Abstract

The use of pre-emergent herbicides in soybean cultivation is an important tool in the management of weeds, reducing the initial competition with the crop. However, these herbicides can cause injury to soybean plants and interfere with productivity. The objective of this work was to evaluate the selectivity of residual herbicides applied in the pre-emergence of soybean crops, in soils with different textural class. For this, two experiments were conducted under field conditions, using a randomized block design, with four replications, containing the herbicides trifluralin (1200 g i.a ha-1), s-metolachlor (960 g i.a ha-1), diclosulam (29,4 g i.a ha-1), imazethapyr + flumioxazin (100 + 50 g i.a ha-1), sulfentrazone (150 g i.a ha-1), sulfentrazone + diuron (140 + 280 g i.a ha-1), clomazone (800 g i.a ha-1) e chlorimuron-ethyl (20 g i.a ha-1), in addition to control (without herbicide). The selectivity of herbicides was determined through visual evalution of phytotoxicity at 07, 14, 21 and 28 days after application, as well as the agronomic and production components of the culture. Through the obtained results it was possible to observe that the soil texture interfered in the selectivity of herbicides, mainly for the herbicides diclosulam, imazethapyr + flumioxazin, sulfentrazone + diuron and chlorimuron-ethyl, which in the sandy texture reduced the soybean productivity.