The continuing evolution of herbicide resistance in major crop weeds is a driving force to develop new weed control strategies. The use of chaff carts and direct bale systems are two sustainable practices that have not been adequately
evaluated.

The objectives of this study were:

• 1) Evaluation of seed retention of important weed species at harvest.
• 2) Evaluation of chaff collection and chaff plus straw collection at harvest to reduce weed infestations.

Preliminary results show that the efficacy of control, among other factors, will depend on the species characteristics and harvest time. The average percentage of relative weed reduction (for only one year of study) was 15% for the chaff collection and 22% for the chaff plus straw collection compared to harvest with the combine alone.