Submitted to: University of Missouri Agricultural Chemicals Short Course
Publication Type: Proceedings
Publication Acceptance Date: 2/10/1997
Publication Date: N/A
Technical Abstract: Biological control is a nonchemical approach available for weed management in crop production and in pasture and rangeland situations. Most successful biological control programs have been associated with classical strategies in which natural enemies of weeds were introduced and allowed to develop populations for control over time. This tactic is effective in pasture and rangeland ecosystems. The inundative strategy in which weed infestations are overwhelmed with massive numbers of natural enemies in order to attain control in the year of release may be best suited for row cropping situations. However, difficulty in culturing many of the effective agents in addition to providing specific environmental requirements for efficacy in the field has limited the widespread adaptation of biological control. Short term success of biological control may first be realized in special situations where conventional herbicides are restricted and where preservation of environmental quality is a major concern. These include natural ecosystem restoration, wetlands, wildlife refuges, and waterways. For biological control to become a practical management option, its effectiveness as a component in an overall weed management program should be demonstrated first prior to devising systems based entirely on biological control. Such options include integrating biological control agents with cultural practices such as tillage and planting dates, crop rotations, cover crops, and using highly competitive crop varieties. Integration provides the opportunity for biological control to be successful as a component of a weed management program as herbicide options become more restricted.