Written by Chris Adams, Oregon State University, June 4, 2021. Survey authors include Elizabeth Beers, Louis Nottingham, Washington State University; Michael Doerr, Wilbur Ellis); David Epstein, Northwest Horticultural Council
In 2020 a Codling Moth Task Force was founded keep up with the evolving challenges to the industry, to evaluate past and current management recommendations, and to provide up-to-date information on codling moth management. One of the first projects was an industry survey which yielded a lot of interesting data. Here are some of the survey results along with some interpretation of what we think it all means.
Organic Fruit Production
More and more growers are responding to market demands for organic apples and pears. Transitioning acres from conventional management into organic production can be challenging, as organic production has a limited set of approved tools for controlling codling moth. In the past, growers might have been classified as just organic or just conventional, today that is no longer the case. Many growers are trying their hand at organic fruit production, with more and more acres in transition every year. For example when asked “what type of orchard management do you use?”, 30% said the where organic, but of those only 14% said 100% of their acres were managed in this way. Similarly, of the 50% who identified as conventional growers, less than half had 100% of their acres managed conventionally. This graph illustrates how dynamic the pome fruit industry is, and highlights the complexity of IPM management decisions. This complex mix of conventional, transitional, and organic pome fruit production may be responsible for reports of increased codling moth damage.
Over the past 20 years, the industry has gone through some amazing changes. Thanks to the efforts of a team of tree fruit researchers here in the PNW, and collaborators from around the world, the industry now has an extensive list of IPM tools for managing pests. The current pheromone-based IPM programs and decision support tools have allowed growers to successfully manage codling moth (and many other pests) without broad-spectrum organophosphates. While successful, these new tools do require proper timing, spray rate, and coverage in order to be effective. When pest pressure is low, small changes to water volume or tractor speed can save labor costs. However, when pest pressure is high, “cost saving” changes in management programs can leave growers vulnerable to fruit injury. Half of growers reported being organic growers, or in transition to organic (Figure 1), yet when asked “what is an acceptable amount of damage?” more than 75% said that fruit injury should be at 0 or 1% (Figure 2) As we try to understand the cause of recent reports of rising codling moth pressure, we will need to ask if expectations are in alignment with current management practices.
Glass half full
When we asked people to describe codling moth injury over the past 3 years, 36% said that damage was unchanged and 28% said that damage had decreased! With expectations of damage at < 1% and so many growers transitioning acres into organic, it is encouraging to see that only 25% said that codling moth damage had increased over the last three years. While we would like to see that number be zero, we think that we are actually in good shape. By focusing on current researched based management recommendations and established fundamentals of IPM we believe that we have the tools to address codling moth challenges.
The Codling Moth Task Force is encouraged by the number of responses we received to the survey and the level of engagement from stakeholders across the PNW. This task force aims to promote training on basic biology, monitoring and management techniques; identify challenges to control; and encourage new research and extension initiatives that will move the industry forward. The 29 member Task Force will resume regular meetings this fall. Updates to our progress will be communicated through WTFRC and at events such as field days and winter meetings.
The Task Force would like to thank Ines Hanrahan for her leadership in this initiative.
Recent article in Good Fruit Grower about Codling Moth Task Force https://www.goodfruit.com/new-task-force-tackles-codling-moth/
Christopher Adams, PhD.
Tree Fruit Entomology
Oregon State University, MCAREC
Chair of Codling Moth Task Force Executive Committee
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