1a.Objectives (from AD-416):
Determine the potential for synergistic interactions between multiple ecologically based tactics for weed management. Develop and test a framework for evaluating multi-tactical weed management that integrates cultural, physical, and ecologically-based methods of managing weeds.
1b.Approach (from AD-416):
We will conduct two multi-year, multi-site field experiments at ARS and PSU to evaluate the individual and combined contributions of ecologically based weed management tactics. In the first experiment, the weed suppressive effects of cereal rye mulch and soybean population will be assessed using a factorial design including several rates of each factor. The second experiment will quantify the weed suppressive effects of mixtures of cover crops by varying species composition and their relative proportions in combination with the timing of management operations. An analytical framework will be developed for determining synergistic or antagonistic interactions between multiple weed management tactics. This framework will allow us to quantify the probabilities associated with multiple tactics applied simultaneously and of multiple consecutive tactics applied in a cumulative systems approach.
Field trials were conducted by ARS and Penn State to test the effect of cereal rye mulch rate and soybean population density on weed population, growth rates, and competitive effect. We used gradient design/analysis to define the functional relationship these factors had on weeds both independently and when combined. Field experiments have been completed and a quantitative framework was developed to evaluate the interactions between multiple weed management tactics. A synthesis manuscript is in preparation.