Submitted to: University of Missouri Agricultural Chemicals Short Course
Publication Type: Proceedings
Publication Acceptance Date: December 13, 1995
Publication Date: N/A
Technical Abstract: Weed management involves systems in which all available strategies are used to minimize the impact of weeds on crop production. Biological control is one method available for weed management. Most successful biological control programs have been with classical tactics in which natural enemies of weeds are introduced and allowed to develop populations for control over rtime. This tactic is effective in pasture and range ecosystems. The inundative tactic 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 adapted for row cropping systems. However, difficulty in culturing many of the effective agents in addition to specific environmental requirements for efficacy in the field has limited progress in widespread use of biological control in these agroecosystems. Short term success of biological control systems may first be realized in special lsituations 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 reduced applications of herbicides, cultural practices such as tillage and planting dates, and with highly competitive crop varieties. These types of integration of biological control into current systems offer augmentative weed control options as herbicide use becomes more restricted.