High-density fruiting walls will facilitate better spray coverage.
The future of integrated pest management will be determined by new knowledge and technology generated by sound science that leads to changes in practices. The support of research by Washington State tree fruit growers provides them with ready access to relevant new knowledge and technology that keeps them competitive in a global marketplace. There will be pressures that drive the needs for new knowledge and technology. Among these are regulatory actions that impact existing practices and technologies, consumer expectations of safe food, and concerns about the impacts of agricultural practices on farmworker health and the environment.
The U.S. Environmental Protection Agency decision to phase out the use of azinphos-methyl (Guthion) in tree fruit crops marks the end of an era where this product formed the foundation of chemical control for the key pest of apple, the codling moth. The future of chemical pest control lies in several new classes of insecticides that hold new challenges and opportunities for growers. The challenges are present because the new insecticides are more expensive, often target different life stages, are less persistent, and require better coverage than the products they are designed to replace. The sheer complexity of having so many more choices for controlling pests is daunting, and Washington State University’s Pest Management Transition Project was designed to assist growers in developing best practices for using new insecticide technologies (see "Learning new tactics" on page 18). The development of the WSU Decision Aid System is a tremendous advancement in assisting growers and crop consultants to deal with the increased complexity of tree fruit IPM (see "WSU Decision Aid System updated" on page 20). The benefits of new insecticides reside in their safety relative to products they are replacing. The easiest benchmark of this safety is the worker reentry intervals of new products that are in hours instead of days.
Chemicals that modify insect behavior like pheromones or kairomones will continue to play an important role in IPM programs of the future. The hand-applied dispenser remains the primary way pheromones are delivered in the field, but the future will provide new delivery mechanisms that hold promise for reducing the cost of mating disruption while increasing efficacy. One such technology would be robotic platforms that can be adapted to multiple tasks from pruning or thinning fruit to placing pheromone dispensers. It will also be possible for these robotic platforms to simultaneously deposit pheromone and a toxicant in a manner that would optimize attraction of a pest to a site where it would become intoxicated but without applying the toxicant to the fruit surface. This could be important if consumers domestically, or in export markets, decide they want fruit with zero pesticide residues. Such a movement is finding more and more popularity in Europe, and it is therefore possible that the demand for fruit with no pesticide residues could eventually impact IPM practices.
Tree architecture, rootstocks, and new varieties will have a significant impact on IPM in the future. The new, high-density fruiting-wall-type apple orchards make it possible to get better pesticide coverage with sprayers that reduce drift. New designs of spray equipment, including unmanned platforms, will optimize the placement of pesticides on the plant surface, improving coverage and providing pest control with reduced rates. Research has already developed rootstocks for apple that are resistant to the woolly apple aphid. There are known genes in apple for resistance to powdery mildew.
There are also likely many other opportunities to explore the insect and disease resistance that naturally occurs in the apple and pear genomes. The excellent young team of scientists, hired by WSU, make up a genetics, genomics, and breeding team for horticultural crops that will eventually identify and incorporate pest resistance into new varieties, in addition to characteristics that provide the enhanced fruit quality desired by consumers. Even a low level of insect or disease resistance in new fruit varieties could tip the balance in the orchard in favor of natural controls, thus enhancing the impact of biological control in IPM.
There is a push to develop new technology for specialty crops with the new farm bill funding of the Specialty Crop Research Initiative. Monitoring has always been a barrier to the full implementation of IPM. Two technologies that could help change IPM through better monitoring are the development of automated traps and scouting. Such traps would count insects and transmit results in a wireless mode to computers, allowing consultants and growers to see results daily without visiting the trapping stations. An automated "scout," also under development, could have the capability of assessing the presence of pests or injury caused by pests. Information provided by any of these technologies could assist consultants or growers in targeting pest control resources in areas where problems occur and avoid overtreating in other areas.
The future holds new advances in knowledge and technology that will result in new IPM practices and create a safer orchard environment for farmers, workers, and beneficial insects, resulting in a sustainable production system that will retain Washington as the premier producer of fresh fruit.