Mechanical weed management

Some current imperfections of mechanical weed management are examined. It is shown that quantitative knowledge on weed seedbank ecology is important to forecast whether pre-emergence soil cultivation can be expected to reduce weed density, weed dry matter or the effectiveness of subsequent cultivations. Post-emergence soil cultivation is limited for control of weeds in narrow-row crops and the weeds within the rows of row crops by low selectivity between crops and weeds. There is an urgent need for further work on timing and intensity of post-emergence soil cultivation. Knowledge on phenological development dynamics of weeds is also lacking and data on crop yield responses to damages associated with post-emergence weed control are extremely rare. Methods of assessing crop damages immediately after post-emergence soil cultivation are weak. in conclusion, the disciplines of weed ecology and mechanical weed management should cooperate in future to create improvements of weed management strategies with major reductions in herbicide usage.