Improve your chestnut IPM program with these easy tips

Scouting and integrated pest management (IPM) resources for chestnut growers are available through Michigan State University.

There are many valuable integrated pest management (IPM) resources and tools available to chestnut producers through Michigan State University. As chestnut production becomes more heavily reliant on real-time information and addresses evolving issues such as potential invasive pests, rising pesticide costs and challenging environmental conditions, Michigan State University Extension is here to assist chestnut producers in maintaining an IPM program that supports economic and environmental sustainability. 

As a relatively new industry, the chestnut industry faces a number of challenges, including developing and implementing standard scouting practices that detect, identify and properly manage for insect and disease pests. This is not a small challenge and protocols will continue to evolve over time as the industry and University learn more about this ever-changing system. Michigan has a long history of horticultural crop production and we have drawn from the pest management experiences of industries like apples and cherries to develop some basic scouting techniques for chestnut producers. 

Growers should be scouting at least weekly during the growing season, noting growth stages, significant weather events, beneficial insects, pest hot spots or any other useful observations in an easily accessible location that they can refer back to in coming years. Growers can start their scouting program with basic visual inspection. To complete a visual inspection, walk a diagonal transect across each contiguous block stopping to inspect the leaves on 10 branches for insects (potato leafhoppers, mites, foliar feeders), phytotoxicity or abnormalities. Growers may need a hand lens or magnifying glass to view mites as they are small and difficult to see with the naked eye at low populations. Growers may also place unbaited, yellow sticky traps at four locations per 5 acre block (two in the interior and two in edge rows). Check and clean or replace these traps as needed weekly. Refer to the Seasonal Pest Occurrence table on the last page of the “Pesticides registered for edible chestnuts, 2015” document to determine the seasonal presence of pests.

As growers walk a transect, they should take the time to inspect the canopy of the trees for rose chafers and Japanese beetles. Also, look for signs of stress or wilt that can be caused by root rot fungi. Growers should visually inspect the trunks as they walk a transect, looking for signs of chestnut blight and sunscald or southwest disease, which are often confusing as they cause similar symptoms. Lastly, growers should be on the lookout for signs of Asian chestnut gall wasps, a potential invasive insect of concern that has not yet been found in Michigan. Asian chestnut gall wasps are easiest to scout for in the fall or winter after the leaves abscise from the tree, but can also be seen during the summer.

When it comes to keeping up with the latest developments that affect chestnut production, MSU Extension is an excellent resource. MSU Extension News for Fruit and Nuts offers the expertise of MSU scientists and educators through online articles addressing pest management in chestnuts and providing weekly scouting reports during the growing season.

Can’t remember to access the page? That’s OK! You can sign up to receive chestnut-related articles via MSU Extension sent out each week by email. You can also opt into other topics or cropping systems of interest to you. To subscribe, simply click the Newsletter Sign-up icon found throughout the MSU Extension website. 

Lastly, MSU offers a number of additional online resources including the MSU IPM Program website, which is devoted to the dissemination of information regarding sustainable pest management practices. For more pest-specific information, visit the insect and disease sections of this page.

This material is based upon work supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under Agreement No. 2013-41534-21068. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

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