Washington State University Cooperative Extension

Areawide IPM Update

The Newsletter of Pheromone-based Orchard Pest Management


Vol. 3, No. 2   February 1, 1998

Inside this issue:

REVIEW OF 1997 CAMP SITES

Web links:

...Ted Alway's Areawide IPM page

...USDA Yakima Areawide IPM page (with CAMP site descriptions)

...WSU-TFREC Entomology home page

...Index to Areawide IPM Update newsletters

Cooperating agencies: Washington State University, Oregon State University, University of California, U.S. Department of Agriculture, and Chelan County.

Cooperative Extension programs and employment are available to all without discrimination.


 

Review of 1997 CAMP sites

I n 1997 there were five CAMP sites that received funding from the USDA Agricultural Research Service for the first time. This money was used for the monitoring supplies and labor needed to monitor for pests across the site, organize this information and distribute it to participants. In contrast with the initial five CAMP sites (Randall Island, Medford, West Parker Heights, Howard Flat and Lake Osoyoos), these 1997 sites received no partial subsidy for the cost of pheromone dispensers, and were funded for only the one year. LetĖs review what happened at each of the sites in their first year of areawide codling moth control.

Progressive Flat:

This site of close to 600 acres is located on a bench above the city of Okanogan, WA. Twenty-five growers participated, and the monitoring and coordination was provided by Ron Moon, himself a grower within the site. Codling moth (CM) pressure has historically been light to moderate here, with two cover sprays providing adequate control for most growers. Leafrollers, although present, have not been regarded as a pest by most growers and no treatments have been targeted for them.

Isomate C+ pheromone dispensers were applied prior to full bloom at the reduced rate of 200 to 250 per acre, and most growers supplemented the pheromone with up to two cover sprays for the first generation of CM. The second generation saw only limited border sprays in high pressure areas. The low CM pressure is reflected in the catch in pheromone traps (one trap per ca. 2.5 acres) of but 2.1 moths/trap/season (1.8/trap first generation, 0.3/trap 2nd generation).

Fruit damage from CM was practically non-existent, with harvest samples revealing less than 0.01% damage. The little damage that was found occurred on orchard borders.

Three species of leafrollers were caught in pheromone traps (obliquebanded, pandemis and fruittree) with obliquebanded leafrollers representing the majority of those caught. No sprays were applied specifically for leafroller control, and fruit damage from these pests was as low as that from codling moth. A few blocks were identified as having higher populations, and some treatments in the year ahead may be needed to keep the populations from increasing to damaging levels. Limited fruit damage from other pests was found at harvest, principally campylomma and cutworms.

In a post-harvest survey, 100% of the growers responding said they had equal or even less fruit damage than in previous years and plan to continue the use of codling moth mating disruption. Several commented on the advantage they see in beginning use of mating disruption while CM populations are low to keep them low, particularly with the anticipated losses in the near future of most of the insecticides presently used for CM control. Ron Moon has taken a job with Northwest Wholesale, an agricultural chemical distributor, and will not be coordinating the siteĖs activities in 1998, but plans to provide training for area growers and encourage a coordinated areawide control effort.

Brewster:

The Brewster Areawide Management project ("BAM") was by far the largest of the 1997 sites at 2400 acres (and had the catchiest acronym!). It created, when combined with close to 2300 acres under CM mating disruption on the adjacent P & G orchards, some 4700 contiguous acres of mating disruption, one of the largest such areas in the world. Forty-one growers participated in BAM in 1997. Coordination was provided by the non-profit, limited liability corporation they formed, managed by a board of area growers and consultants.

Historically, CM pressure has been low to moderate, but populations of obliquebanded leafrollers (OBLR) have been high and can cause considerable fruit damage for many growers. CM traps were installed at one per 5 acres, and OBLR traps were placed at one per 15 acres. Isomate C+ was used at about 200 dispensers/acre, with some higher rates used on orchard borders and in historical "hot spots." Most growers applied one cover spray of Guthion for the first generation. For leafrollers, Bt sprays were applied around bloom time, targeting overwintering larvae, and more Bts were applied in July for summer generation larvae.

Codling moth were generally well controlled in 1997. Catch in traps was very low in most areas (2.5 per trap for the year), with second-generation catch only 10% of first-generation catch. Fruit samples from bins at harvest showed an average of 0.2% CM damage, with 55% of the blocks having no damage at all. Leafrollers were another matter. Fruit damage was just as bad as in previous years, with harvest samples revealing an average fruit damage of 1.7%. Leafroller damage was found at some level in 85% of the blocks, with 30% of the blocks sampled having over 2% of the fruit damaged. Leafroller catch in pheromone traps averaged 46 per trap for the season, no higher than or even below the numbers found in previous years in the area. There appeared to be little correlation of leafroller catch in traps with the orchard blocks having the most fruit damage.

Grower attitudes at year end were "mixed." Cover sprays were reduced from over two on average in 1996 to about one in 1997. The cost of the CM and leafroller monitoring here, for traps and labor, was about $12/acre for the season. However, the extent of leafroller damage was disappointing. In addition, many growers had to apply unexpected treatments for apple scab due to the wet spring, and many experienced high leafminer populations, for which treatments were applied in some cases. This leafminer problem was apparently unrelated to the use of mating disruption, as it occurred in other blocks in the region with all types of pest control programs. Nonetheless, BAM will continue in 1998, with the full extent of grower participation to be determined by the spring. They hope to incorporate extensive use of the "dual" pheromone dispenser (Isomate CM/LR) that contains both CM and leafroller pheromones, if it is priced competitively. Large trials with this dispenser in the Brewster area in 1997 showed big reductions in leafroller-caused fruit damage, where its use was combined with other leafroller management tools.

Manson:

This site along the north shore of Lake Chelan involved 68 growers and 1014 acres of orchard, including 96 different blocks. Coordination for this site was provided by the team of Wally Penhallegon, of Trout-Blue Chelan (a fruit packer) and Marty Robinson, of Northwest Wholesale (an agricultural chemical distributor). Codling moth pressure had been moderate to high in the area, with growers applying typically 3 to 5 or more covers each year, and still having unac-ceptable damage in areas. Leafrollers were not considered a problem. The use of mating disruption was complicated in the area by the many small blocks, the many interspersed residences and roads, the hilly topography and the frequent downlake winds.

Nonetheless, almost all growers within the chosen area elected to participate. Isomate C+ dispensers were installed at 200 per acre in most blocks, with a few growers opting for rates of 300-400/acre. CM traps were used at an average 3.0 acres per trap, and both pandemis and obliquebanded leafroller traps were installed. Two to three cover sprays were applied for first-generation CM, with limited sprays applied to some borders and hot spots later in the summer. CM catch in pheromone traps declined sharply through the year, from 5.3/trap in the first generation to 0.9/trap in the second generation. Leafroller catches remained low throughout the site, and no damage to fruit was found at harvest.

Growers were generally quite pleased with the results at harvest, with many stating that fruit damage from CM was the lowest they had seen in many years. There were pockets of damage from both campylomma and stinkbug, both pests causing some problems throughout the region in 1997. No extensive bin sampling for fruit damage was done here. This project employed three different scouts through the course of the season, and eventually lost them all, either because they found more attractive work elsewhere or could not do the job adequately. The need for reliable and competent individuals to do this monitoring work can be a limitation for these information-intensive pest management projects, as the work is important and exacting but also often tedious and physically demanding.

In 1998, mating disruption will likely expand in the Manson area and elsewhere in the Chelan Valley, as more and more growers and consultants have successful experiences with its use. Mating disruption use is being promoted by several of the fruit packers in the area, who see its inclusion in a pest managment program as a means to reduce, or keep low, the damage from codling moth and to help address the concerns posed by the FQPA for themselves and their growers.

West Wapato:

This CAMP site involved 18 growers and nearly 900 acres of apples and pears in the Lower Yakima Valley. Coordination was provided by Brad Higbee, of the USDA-ARS lab near Wapato. It was a fairly flat site and representative of many orchards in the area, being surrounded by pome and stone fruit orchards, hop yards, grapes and other crops. Codling moth pressure had been moderate to high, with typically 3 to 5 covers being applied.

Codling moth traps were hung throughout the area at about one per 2.5 acres, and both pandemis and obliquebanded leafrollers were monitored with pheromone traps. The growers installed the pheromone dispensers by bloom; about 45% of the acreage was treated with Isomate C+ at the full rate of 400/acre, close to 30% was treated with this dispenser at a reduced rate of 200/acre, and approximately 25% was hung with the Checkmate CM dispenser. Most growers applied two cover sprays for the first generation, with some higher-pressure sites getting one or more covers aimed at the second CM generation.

CM catch in pheromone traps confirmed the high pressure in the area. First generation catch averaged nearly 8 moths per trap; in the second generation this was reduced below 4 per trap. Most growers had minimal fruit damage at harvest, with a few exceptions where CM populations were not controlled. One of the problem sites was a block with rows of large Golden Delicious trees interspersed with many rows of small, non-bearing trees, difficult conditions in which to maintain good pheromone levels for mating disruption. High numbers of pandemis leafrollers were caught, with a mean seasonal catch of over 500 per trap, but leafroller larvae were rarely found and damage to fruit was minimal.

In a post-harvest survey, 11 of the 14 growers responding said they had less CM damage than the year before, and one said it was the same. Most of those responding said they planned to use mating disruption in 1998. It appears that there will not be a coordinated areawide program here, however.

Mendocino:

This CAMP site is near the city of Ukiah, CA, and in 1997 included 550 acres and 10 growers. Coordination was provided by Dr. Lucia Varela, Area IPM Advisor with University of California Cooperative Extension. She began working with the site in 1996 when mating disruption was first used here on 400 acres. The site is all pears, 80% of the acreage being the Bartlett variety. Isomate C+ pheromone dispensers were applied twice, 400 per acre being installed in late March (bloom time), followed by 200 per acre in early June (ca. 900ƒD after biofix). In 1997, the second year of mating disruption use here, 66% of the acreage applied no cover sprays; the remaining acreage applied one or two covers, most of this to blocks in their first year of mating disruption. The use of organophosphate insecticides was reduced in 1997 by 85% from 1996 levels, following a 65% reduction from 1995 to 1996.

CM populations, as measured by catch in pheromone traps, were reduced 35% on average across the entire project from 1996 levels, and up to 75% in blocks that had the highest populations. Fruit damage from CM was also down, with nearly 90% of the acreage having 0% damage, and the remainder having only 0.1-0.3% damage. Two adjacent sites not using mating disruption applied two or three covers and at harvest had between 1 and 2% damage, indicating that there is significant CM pressure in the area.

The population of obliquebanded leafrollers increased, as did fruit damage from this pest. In 14 of the 36 sites monitored damage was detected in the range of 0.1 to 0.4%; the one site that did not apply Lorsban in the delayed dormant spray had damage from leafroller of close to 1.0%. Fruit damage from true bugs, either boxelder or stink bugs, also increased in 1997. Eighty percent of the blocks had some detectable level, with damage being concentrated in blocks close to the Russian River. Weeds and shrubs growing outside the affected blocks are the suspected source of these true bugs, and more attention will be paid to monitoring and possibly reducing these sources. A problem with true bugs has appeared in other areas as well, including CAMP sites in Medford, OR, and in the Lake Chelan Valley of Washington.

This site will continue in 1998 without CAMP funding, with Lucia Varela continuing as coordinator. They may add several growers and will likely use only one application of Isomate C+, to improve the economics of this pest control system.

The year ahead

Although there will be no CAMP funds for any of these sites in 1998, I expect that mating disruption will continue to be used by the majority of the growers. I will follow up with these growers to determine if and how it is used. To what extent the growers are involved in a coordinated areawide control program, in which intensive monitoring of pests is done and information and costs are shared, is yet to be determined. Areawide control programs offer advantages to participants by reducing some costs and more easily reducing and maintaining low populations of key pests like codling moth. Their importance has increased with the changes in pesticide use that will probably result from the Food Quality Protection Act of 1996.

However, there often are barriers to areawide programs to overcome, including growersĖ associating with competing suppliers and fruit packers, resistance to cooperating with a large number of neighbors, and having to pay for a new service or one that was apparently "free" before. Six new CAMP sites are being funded in 1998 for one year only, including an estimated 5200 acres in Washington and 600 acres in Colorado. A key measure of the success of the CAMP will be in how these sites continue after the "seed" money is gone, and the extent to which the CAMP has helped to demonstrate the successful integration of codling moth mating disruption into effective and economical orchard pest management programs.


Ted Alway, Editor
Phone: (509) 664-5540
Fax: (509) 664-5561
e-mail: alway@coopext.cahe.wsu.edu

Partial Funding provided by: Washington State Tree Fruit Research Commission, U.S. Department of Agriculture-Agricultural Research Service.

AREAWIDE IPM UPDATE
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