Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 23, 2002
Publication Date: N/A
Interpretive Summary: Fresh market vegetable producers account for a significant proportion of the U.S. consumption of methyl bromide and employ production systems designed to use a single application of a broad spectrum biocide to disinfest soils prior to planting. While nonchemical methods including host resistance, crop rotation, organic amendments, soil solarization, and cultural practices have been used to control soilborne pests in vegetable production systems, they do not offer the same broad spectrum of control, consistency between sites and crops, and logistical compatibility as methyl bromide. Thus, it is highly unlikely the growers relying on a single tactic to manage soilborne pests will find a suitable nonchemical alternative to replace methyl bromide, although some nonchemical methods may be used to support less effective chemicals. Nonchemical methods are ideally suited for an integrated approach to the management of soilborne pests. However, many of the components of IPM systems including sampling programs and economic thresholds are not available or economically feasible for many soilborne pests. In addition, growers who have relied on a single tactic approach for 30 years or more are hesitant to assume the additional responsibilities of managing biological information. Proactive pest management programs are based on the use of nonchemical methods and the biological information of soilborne pests and offer potential for the development of biologically sustainable pest management systems. Successful application will require redesigning crop production systems to minimize pest outbreaks. It is highly unlikely that growers will undertake that task without additional support from industry.
Technical Abstract: Nonchemical methods including host resistance, organic amendments, crop rotation, soil solarization, and cultural practices have been used successfully to control soilborne pests in fresh market vegetable production systems. Their suitability as alternatives to methyl bromide will depend on the approach to pest management adopted by the grower. Traditionally, methyl bromide has been used in production systems that rely on a single application of a broad-spectrum biocide to disinfest soils prior to planting. Nonchemical methods are not suitable for this single tactic approach to pest management because they do not provide the same broad spectrum of activity or consistency as fumigation with methyl bromide. Nonchemical methods are compatible with an integrated pest management (IPM) approach, where multiple tactics are used to maintain damage from pests below an economic threshold while minimizing the impact to beneficial organisms. However, adoption of IPM is hindered by the paucity of economically feasible sampling programs and thresholds for soilborne pests and by a reluctance of growers to commit additional resources to the collection and management of biological information. A novel approach to the management of soilborne pests is to design the crop production system to avoid pest outbreaks. Using this `proactive' approach a tomato production system was developed using strip-tillage into existing bahiagrass pasture. By minimizing inputs and disruption to the pasture, growers were able to reap the rotational benefits of bahiagrass without waiting extended periods of time to cultivate the rotational crop.