Atributos fisiológicos na cultura da soja e controle de plantas daninhas em função da aplicação de herbicidas

Abstract

Weeds interfere in crop development due competition by environment resources, may results in high losses on yield cultivated species. To reduce the weeds infestation in crop lands, it is necessary adoption of control measurements, like chemical method. The herbicides application, although selectives to the crop, may cause high levels of phytotoxicity to the plants, and high levels to oxidative stress reducing yield and physiological seed quality. The objectives of this research were: evaluate the control of three weed species to phytointoxication and the effects of productivities compounds of two soybean cultivars, caused by pre and post emergence herbicide spraying; quantify physiological seed quality due the application of these herbicides; and determine oxidative stress level caused to soybean plants due weed competition or herbicide application. So, two experiments were conducted on field, Centro Agropecuário da Palma/UFPel, 2013/2014 season, and two experiments in greenhouse, Campus Capão do Leão/UFPel, 2014/2015 season. In general, it observe that all the evaluated herbicides caused injury to soybean plants, wherein, between pre-emergents, sulfentrazone caused higher injury, while, between post-emergents, carfentrazone-ethyl was the most phytotoxical. Metribuzin spraying in pre-emergence and the interference imposed by the weeds, affect negatively soybean physiological seed quality, being variable due the cultivar. Higher oxidative stress level between pre-emergents herbicides was observed in plants treated with diclosulan, while to the post-emergents, carfentrazone-ethyl spraying caused higher stress.