Weed flora in rice areas under distinct cropping systems, herbicide and irrigation managements
Year: 2018
Type: article
Abstract: We aimed to evaluate the incidence of weeds in the pre-planting of the summer crop as a function of planting system, herbicide use and irrigation management.The experiment was installed in field conditions, in RBD and 3 x 2 factorial scheme with eight replications.Treatments consisted in submitting rice to three management factors: water managementcontinuously flooded or intermittend irrigation (Factor A), coupled to the application (traditional control) or not (semi-ecological system) of herbicides (Factor B), and planting systemconventional soil tillage, minimum tillage and no-till systems (Factor C).One year after rice cultivation, preceding the planting of the next cropping season, phytosociological evaluations of the weed communities were carried out.We assessed the overall infestation and weed species composition, which were classified by their respective density, frequency and dominance.We also estimated the diversity coefficients of Simpson and Shannon-Weiner, and the sustainability coefficient of Shannon; treatments were also grouped by similarity in weed composition.In flood-irrigated rice, no-till provides the lowest levels of weed infestation and, together with the conventional cropping system, results in values closer to the ecological sustainability; The application of herbicides in flooded rice crops reduces weed infestation, increases diversity and equalizes the ecological sustainability, compared to areas without the application of weed management methods.However, chemical control leads to the selection of resistant or tolerant species to herbicides, such as Polypogon sp.;Both continuous and intermittent water management systems did not cause changes in the level of infestation, composition or diversity coefficients.
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDGs: Zero hunger, Life on land
Open Access status: diamond
OpenAlex ID: W2887325482