Abstract
Japanese feed corn production must be more efficient and less reliant on herbicidal weed control to both reduce environmental concerns and remain economically viable. As an alternative to herbicide, we tested the effects on crop yield of differing tillage systems (normal and intensive) for control of C. japonica in annual corn fields in Japan. Normal fall tillage, with or without intertillage, significantly reduced fresh weight C. japonica at harvest and maintained corn yield. Intensive fall tillage further reduced fresh weight C. japonica at harvest while maintaining corn yield. Fall tillage decreased C. japonica density, above-ground biomass, individual top weight, and individual rhizome weight at the end of the weed control period. Our data indicate that conventional procedures plus normal fall tillage in C. japonica infested fields maintained corn yield equivalent to weed free fields but did not reduce infestation. To control C. japonica more effectively, we recommend conventional procedures plus intensive fall tillage to minimize C. japonica density while maintaining corn yield. Suggested tillage systems do not require additional herbicide or machinery investment to control C. japonica.
