|Vol. 3, No. 7||July 1, 1998|
Inside this issue:
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.
Yakima Valley Orchard Pest Management Tour
Temperatures and Pest Models for Orchard IPM
Another "old, reliable" device used by several consultants is the recording hygro-thermograph. The most common one is manufactured by Belfort, Inc. (available from Robert E. White Instruments, Boston , MA, 800/992-3045, $1800 to $2000). This battery- or mechanically-powered device continuously records on a chart for one week the temperature, relative humidity and, with an attachment, leaf wetness.
There is an increasing number of electronic devices being used by consultants and growers around the state. These record daily high and low temperatures and/or calculate degree day accumulations for pest development models. Perhaps the most widely used is the Datascribe Jr®. (Avatel, Inc., Fort Bragg, CA, <email@example.com>, $129). A weather shelter is available ($100) and software is also needed ($60). This battery powered device records temperatures at selected intervals. Data must be downloaded into a computer, laptop in the field or desktop in the office, or into the pocket sized data shuttle (Transporter®) that Avatel sells ($249). Avatel also sells HarvestGuard® ($179), a degree-day accumulator. A radiation shield/weather shelter is available ($69). Upper and lower temperature thresholds are entered, and degree days are calculated using the daily aver-age, single sine or hourly methods. The device is read in the field, with no software or downloading required, but high and low temperatures are only shown for the previous 48 hours.
Another device being used is the Leaf Wetness/Air Temperature recorder from Spectrum Technologies (Plainfield IL, <firstname.lastname@example.org>, $395). Software is needed ($59) for this device which is mounted in the tree canopy. One consultant is using the HOBO temperature recorder (Onset Computer Corp., available from Gempler's, Belleville, WI, <www.gemplers.com>, or Radio Shack). This small device ($49) requires software ($19) and the data must be down-loaded into a computer or data shuttle ($159). They also sell a weather shield for the device ($49).Weather Stations: Many growers and consultants use weather information available electronically from weather stations, either using it alone or in conjunction with site specific orchard data. The most widely used system is PAWS (Public Agricultural Weather System), operated by Washington State University. PAWS maintains a network of over 40 agricultural weather stations in Central Washington, heavily concentrated in the Yakima Valley, Lower Columbia Basin and Okanogan County. Annual subscription rate is $130 (contact <email@example.com>). Weather data includes high and low temperatures, precipitation and hours of leaf wetness. Pest model summaries are available for many sites. There is also an increasing number of private systems of weather stations that growers and consultants are using in different regions. One example is the Adcon system operated by Trout-Blue Chelan in the Chelan Valley. Pest Model Information: Phenological models are now used to track development of many orchard pests and to aid in determining the risk of damage and the timing of sprays. Models for codling moth, leafrollers (both pandemis and obliquebanded), cherry fruit fly, apple scab and fireblight are being used throughout the state. Most of these models can be obtained from WSU Cooperative Extension offices in Central Washington. Models for codling moth and pandemis leafroller can be downloaded from the WSU-Tree Fruit Research and Extension Center in Wenatchee at <www.tfrec.wsu.edu/entom.html>. The obliquebanded leafroller model developed by Dr. Jay Brunner is found at <www.tfrec.wsu.edu/IPMnews/IPM060197.html>. Tim Smith, tree fruit agent for north central Washington, calculates and distributes weekly model information on key pests; this information is available through PAWS and at the home page for WSU Cooperative Extension for Chelan, Douglas and Okanogan Counties (www.ncw.wsu.edu/). Oregon State University provides online information on the development of a number of pests of tree fruits and other crops. The online models use information from weather stations across Oregon and from a number of Washington sites. Users can also use their own weather data. Find it at <osu.orst.edu/Dept/IPPC/wea/>.
Five sites received one year of funding for 1997: Ukiah, in California, and Progressive Flat, Brewster, Manson and West Wapato in Washington. The Ukiah site continues as a coordinated, areawide project this year and has grown to involve 900 acres, up from 550 in 1997. Dr. Lucia Varela, of UC Cooperative Extension, continues as the site coordinator. CAMP funding was replaced, in part, with money from the California Department of Pesticide Regulation. The growers intend to assume the management of the site in 1999 and continue as an areawide program.
The experiences in the Washington sites, with no outside funding sources or state employees, are somewhat different. Only the Brewster site has continued with a coordinated areawide program. Almost 1000 acres make up BAM (Brewster Areawide Management) this year, down from the over 2000 acres involved in 1997. However, monitoring data is being pooled with the pest information coming from the over 2000 acres of mating disruption being monitored on the adjacent P&G and Gebbers Farms orchards. BAM growers are paying $7.50/acre for monitoring of codling moth and leafrollers this year. Many Brewster growers have stopped using codling moth mating disruption in 1998; due to low codling moth pressure and high leafroller populations many orchardists decided it was not cost effective. Many of those still using mating disruption are using the recently registered Isomate CM/LR, or "dual," dispenser that contains both codling moth and leafroller phero-mones. The BAM group applied for and recently received two grants, from the USDA-CSREES and SARE program, totaling over $35,000, to be available in 1999 for research work and further areawide pest management implementation.
At the other three Washington sites there are no continuing coordinated areawide control programs, yet most growers have continued to use mating disruption. In Manson, codling moth mating disruption use has expanded further, as the positive experiences of 1997 convinced many growers of its value in this relatively high pressure area. All of the 30 growers surveyed said they were continuing mating disruption use, with nearly a third of them expanding its use to new blocks. The largest fruit packer in the area, Trout-Blue Chelan, is doing extensive monitoring with pheromone traps, but only for its member growers. At Progressive Flat nearly all growers are continuing to use mating disruption, despite the relatively low codling moth pressure there. Most West Wapato growers are also continuing use of mating disruption.
1997 saw the first mating disruption use for 80 to 90% of the growers at each site. Few growers at these latter three sites have discontinued its use despite no further support from CAMP, an indication that they have found it to be economical and effective. When asked why they continued to use mating disruption the most common reply was smply, "It works!" In addition to saving money, reducing damage or both, many growers said they have continued using the technique to prepare for anticipated changes in pest control programs. "It's the way of the future," said one, while another said he used it "to pacify the anti-pesticide idiots!"
Mating disruption acreage in Washington has been increasing nearly 40% per year for several years, yet true areawide control efforts are relatively few. With an areawide approach adjacent orchards not only use codling moth mating disruption but also share many of the costs for monitoring programs and the information derived from them. This is important for more rapid, thorough and cost-effective control of codling moth, and for helping growers readily adapt to further pest and pest management developments.
Leadership from within the site, often from a participating grower or consultant, may be the most important factor in creating a lasting organization. Effective leadership can work with growers to cajole, convince, educate, encourage, or even bully them to participate! Experience and information from other areawide efforts regarding organization, communication and monitoring is of great value. An outside source of supporting funds, for one or more years, has been helpful in creating a site, providing initial incentive to participate for some growers. A common barrier to forming an areawide site is often posed by the competing fruit packers and agrochemical suppliers who work with growers in an area, for whom sharing information and resources can be difficult. It may be necessary to create an organization independent of these other companies, as in Brewster with the formation of BAM by that area's growers and consultants in early 1997.
The Environment Program of the Pew Charitable Trusts looks for opportunities to assist growers in developing and adopting more stable, biologically-based pest management systems, and Washington pears met their criteria. The Washington State Horticultural Association is managing this project, for which nearly $500,000 (about 50% each from the EPA and Pew) has been allocated over three years. Brooke Peterson has been hired as the Project Coordinator.
The goal of the PIPMP is to develop the safest, lowest risk pest management program for Washington pears that "can keep a pear grower in business," providing for both good pest control and good crop marketing. The emphasis is on applied technology, not research, and developing a program that will endure and be of lasting benefit to pear growers long after the three years of the project have passed.
Specific goals include reducing the use of organophosphate insecticides within the participating blocks by 60% and implementing programs to lessen the development of pesticide resistance on 100% of the acreage. Acreage goals have also been established for 500 acres in 1998, 2,000 in 1999 and 4,500 in 2000.
For 1998, the PIPMP already has close to 640 acres in the Yakima Valley, involving over 40 growers. In the Yakima Valley, pear production is dominated by Bartlett pears, most grown for canning. Most of the PIPMP acreage this year is in Bartletts, often with Anjou pear pollenizers. At present there are 62 separate pear blocks, ranging in size from 1 to 42 acres. All growers are using codling moth mating disruption, primarily with the Isomate C+ dispenser at rates of from 200 to 400 per acre. Using mating disruption allows them to reduce or eliminate codling moth cover sprays, the principal use of organo-phosphate insecticides in Yakima Valley pears. Although many of the pear blocks are small, they are often part of a larger area, including apples, that is treated with pheromone dispensers.
Mating disruption is used on a far smaller proportion of Washington pears than apples. This is due largely to the lower susceptibility of pears to codling moth, resulting in fewer cover sprays being applied and therefore less opportunity to save money by reducing spray costs. Pear growers have other reasons for using mating disruption. Its use can improve biological control of some secondary pests, including pear psylla and spider mites, and using mating disruption may become part of the most economical pest management program, if organophosphates are no longer available.The PIPMP is monitoring codling moth and leafrollers throughout the program acreage with pheromone traps and is using leaf samples to count pear psylla and mites. Fruit will be monitored for pest damage, both on the tree and in bins at harvest. The PIPMP will develop standardized monitoring protocols for pear pests that can be used by consultants and growers in the industry as they implement a more biologically-intensive pear IPM system.
The PIPMP will increase the acreage involved next year and, based on this year's response, will probably find many willing participants in the Yakima Valley. The program could also extend to the pear growing districts of North Central Washington, where the bulk of Washington's fresh market pears are grown. Many growers in this region must contend with the grape mealybug in their pear blocks, for which organophosphates remain the principal control method; growers are anxious to develop control methods that don't rely upon these insecticides before their use in cancelled.We may have only a few years to adjust to the pest control changes that will result from implementing the FQPA. Growers and consultants are increasingly looking to programs like PIPMP and CAMP (Codling Moth Areawide Management Program) for information to help guide their transition to an uncertain pest control future. The PIPMP has ambitious goals that, for the sake of our pear industry, we hope it attains.
Ted Alway, Editor
Phone: (509) 664-5540
Fax: (509) 664-5561
Partial Funding provided by: Washington State Tree Fruit Research Commission, U.S. Department of Agriculture-Agricultural Research Service.
WSU Cooperative Extension, Chelan County
400 Washington St.
Wenatchee, WA 98801
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