Identificação taxonômica de espécies de capim-colchão infestantes da cultura da cana-de-açúcar no Estado de São Paulo e eficácia de herbicidas no controle de Digitaria nuda

摘要: The continuous use of herbicides from the chemical groups triazines and substituted ureas has imposed a selection pression upon tolerant species crabgrass (Digitaria spp), in sugarcane plantations, causing phenomenon weed shift, by reducing populations susceptible increasing proportion this genus. In order to scientifically elucidate phenomenon, research was developed, under field conditions, with following objectives: a) evaluate agronomic efficacy used crops control D. nuda b) taxonomic identification Digitaria selected areas that received repetitive applications. Eight herbicide treatments (ametryne, diuron, tebuthiuron, diuron + hexazinone, imazapyr, isoxaflutole, metribuzin e imazapic), applied during pre-emergence were used, percentage evaluated at 15, 30 60 days after application (DAA). population carried out analytical key, through observation plant morphologic characteristics. specie controlled lower level imazapyr imazapic. However, ametryne, isoxaflutole showed good until DAA.