Accelerating Adoption of Biopesticide-Based Controls in Michigan Apple Production With Areawide Management of Codling Moth
We are leveraging funds from several sources to continue, and expand, an areawide codling moth (CM) control program for apple producers centered on the use of pheromone mating disruption, CM Granulosis virus, reduced-risk insecticides, and intensive monitoring. Areawide CM management involves the cooperative efforts of adjacent growers to deploy strategies aimed at reducing CM population densities. The best successes with mating disruption, worldwide, have been achieved where large, contiguous areas have been treated with pheromone. The first Michigan areawide project started in 2004 in the Fruit Ridge region of Sparta, MI, with funding from the USDA Sustainable Agriculture Program. The Sparta region is representative of regions around the state where OP-based management programs are failing to control CM, and growers are experiencing unacceptable levels of worm-infested fruit at harvest. The 2004 Michigan areawide project directly included eight farms comprising approximately 800 acres of apple. With funds from EPA Region 5, project acreage nearly tripled to 20 farms on 2100 acres in 2005. Grower interest in areawide management has been stimulated, and grower groups from different apple producing regions of the state have appealed to the project team to help establish this management approach in their regions. We are documenting the effectiveness of this approach through direct comparisons with conventional programs outside the project area, using the project as a platform from which to educate growers that a biopesticide-based control program can be efficacious and economical, and to facilitate greater adoption of mating disruption, CM Granulosis virus, and reduced-risk insecticides.
Project goals and objectives
To expand and conduct an areawide approach for control of codling moth, combining mating disruption, granulosis virus, judicious use of insecticides, and intensive monitoring practices, from the current 5% (2100 acres) to 13% (5000 acres) of the Michigan apple acreage in 2007. Also, 80% of cooperating growers will realize a 50% reduction in the use of OP insecticides as compared to farms outside of the areawide project.
The project expanded from 8 growers on 800 acres in 2004 to 20 growers on ca. 2100 acres in 2005 on apple farms located in Kent and Ottawa counties, MI. In 2006, efforts were focused on expanding the project to 2 new regions of the State, Southwest, MI and Northwest, MI, resulting in an increase in project participation of 30 growers on 2800 acres in 2006. Further expansion was realized in 2007 with the addition of 120 acres in Monroe County in Southeast MI, and again in 2008 with the addition of 3 farms in the SW region. Performance target one for this grant was an increase in MI apple acreage implementing AW management to 5000 acres. Overall, the project realized a 3.75 fold expansion to ca. 3000 acres, and an increase from 8 growers to 33 growers from 2004 to 2008 using funds from EPA Region 5/American Farmland Trust. While not attaining the goal of project expansion to 5,000 acres, the project has served as a catalyst to promote the adoption of pheromone mating disruption in the wider Michigan apple industry. Over 8,000 acres of MI apple were treated with mating disruption in 2007, up from ca. 4000 treated acres prior to the start of the project.
Blocks deploying pheromone disruption for four years reduced the overall number of companion insecticide applications from 10.1 to 5.2 applications (includes CM virus) during the time span of 2004 to 2007. The average application of organophosphorous insecticides targeting CM dropped from 5.8 pounds in year one to ca. 2.2 pounds in 2007, a 65% reduction, exceeding the 50% goal of objective 2. Fruit injury from CM was 0.7% in the AW in 2007, and 5.5% in neighboring non-disrupted farms outside the project.
In blocks deploying pheromone disruption for four years, captures of male CM in pheromone-baited traps were reduced 82%. Fruit injury attributed to CM was 30% lower in AW blocks than in blocks using MD on individual blocks outside the AW. Moreover, fruit injury was 95% lower in AW blocks than in non-mating disrupted blocks located outside of this program.
This project has had a major impact in advancing the adoption of pheromone mating disruption by apple producers in the state of Michigan. Cost of MD deployment and biological monitoring ranged from $125-$170/acre, depending on number of dispensers per acre and type of dispenser chosen. The four-year mean returns for reduced insecticide use and increased pack-out of non-damaged fruit ranged from $210-$305/acre. The net returns exceeded net costs at about a 1.75:1 ratio for the 20 farms studied in this analysis, strongly indicating that AW deployment of MD for CM is a cost effective management approach. Areawide mating disruption of CM has been demonstrated as an efficacious and economical management strategy, and is being readily adopted by growers.