Submitted to: Weed Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/24/1997
Publication Date: N/A
Interpretive Summary: Computer simulation tools provide useful means to predict the impacts of various management strategies on crop yields. ALMANAC is a simulation model which predicts the impact of various weed infestations on crop yields. In this study, the model was found to accurately predict the impact of weeds on wheat yields in France. This model shows promise as a tool to effectively evaluate the impact of various weed control strategies on crop yields.
Technical Abstract: ALMANAC is a dynamic model for plant growth, water balance and soil nitrogen dynamics that can simulate two or more competing species. The simulation of competition for light is based on Beer's law, allowing for different extinction coefficients for each species. Light is partitioned between species based on k-values, leaf area index and plant heights. The model simulated competition for water and nutrients. The model was evaluated in Dijon, France using four years of experimental data on wheat:oat mixtures. Wheat grain yield was reasonably simulated with a root mean square of 0.10 to 0.35 t per ha. Competitiveness of oats was corrected simulated. The model appears to be a reasonable tool for estimating damage thresholds for weed control programs.