A decision-making scheme for managing the risk of damage to succeeding crops from carry-over of pesticide residues in soil

The introduction of highly active herbicides, such as the sulfonylureas, not only led to improved weed control but also to a greater threat to sensitive following crops. A number of methods can be used to investigate the threat posed to following crops by a new herbicide. The paper proposes a decision making scheme to be used to judge the extent of testing required and the most suitable methods to use. It is the result of the work of the Efficacy Evaluation Panels of the European and Mediterranean Plant Protection Organisation (EPPO). A formal EPPO Guideline in this area will be produced at a later date. The decision-making scheme also suggests ways in which any risks to following crops identified can be managed by appropriate label warnings, such as on the intervals needed before a sensitive succeeding crop can be planted.