Effect of tillage on recruitment depth of five weed species measured in situ in zero and conventional tillage fields in Manitoba
Du Croix Sissons, Michelle J.
Knowing the depth of weed seedling recruitment and how tillage affects the depth of recruitment can help in the development of improved weed control methods. Weed seedling recruitment depth is a better measure of seed placement than weed seedbank counts. Depth of recruitment of wild oats (Avena fatua L.), volunteer wheat (Triticum aestivum L.), green foxtail (Setaria viridis L. Beauv), wild buckwheat (Polygonum convolvulus L.) and barnyard grass (Echinochloa crus-galli L. Beauv) seedlings were measured in 1997 and 1998. The survey included 44 zero tillage and 44 conventional tillage fields over the two field seasons. Detailed information for each field was collected from farmers involved in the survey, to allow for the development of a tillage index. A morphological marker was identified on wild buckwheat so recruitment depth of this weed could be measured in the field. Determining the depth of weed seedling recruitment in zero and conventional tillage fields is the first step in the development of predictive recruitment models. Before the models are developed, farmers can determine the depth of weed seedling recruitment in their own fields and concentrate weed control at that depth. (Abstract shortened by UMI.)