Seasonal weed response to integrated crop management systems
Weed plant density was monitored to determine the effect of various integrated crop management systems on weed population levels and evaluate the efficacy of the various management practices. The management systems studied primarily varied tillage and herbicide inputs. Weed plant density was determined in spring, prior to in-crop management and after in-crop management in each year of the study. Also, weeds were counted after in-crop management prior to the establishment of the management systems. Multivariate analyses were used to determine the response of the weed communities to the management systems. Principal response curves were used to illustrate seasonal fluctuations and trends in weed densities. Stinkweed, lamb’s-quarters, wild buckwheat, redroot pigweed, wild mustard and Russian thistle are best controlled with in-crop herbicide applications. These species increased over time in the no herbicide high tillage system and low herbicide systems. Winter annuals, perennials and early spring annuals were found to increase in the lower herbicide zero-tillage systems. These species tended to be found in high densities in the spring and not effectively controlled in-crop.
tillage, herbicide, cropping systems
Soils and Crops Workshop