Scouting Tips for Onion Thrips in Onions
Christy Hoepting, Extension Vegetable Specialist
Cornell Vegetable Program
To find the first thrips of the season, look deep into the leaf axils. Inspect 20 to 30 plants and count the total number of onion thrips (OT) per plant and divide by the average number of leaves per plant to get the number of OT per leaf. Thrips feeding causes silvery streaking along the leaves. If you can already see thrips feeding damage that is also a good indication that it is time to spray. If there is a lot of feeding damage, than you likely missed a timely first spray.
![Close-up of the leaf axil of a 5-leaf onion plant that is spread open. Five tiny brown Close-up of the leaf axil of a 5-leaf onion plant that is spread open. Five tiny brown](https://rvpadmin.cce.cornell.edu/images/submission/e43f10ac883390d96422d4979b429722.jpeg)
![Close-up of onion leaf axil zooming in on about 30 tiny 0.5 to 1.2 mm in length light yellow slender thrips in a cluster. Close-up of onion leaf axil zooming in on about 30 tiny 0.5 to 1.2 mm in length light yellow slender thrips in a cluster.](https://rvpadmin.cce.cornell.edu/images/submission/9948264d6581fd1495dcdeaf18d0979c.jpeg)
![Side view of an onion plant. Pale green dashes from thrips feeding creates a streaked look to the leaves. Side view of an onion plant. Pale green dashes from thrips feeding creates a streaked look to the leaves.](https://rvpadmin.cce.cornell.edu/images/submission/20bc42bd312137f0cf02e0dafa8fc212.jpeg)
Scouting Tips for Onion Thrips in Onions (pdf; 239KB)
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Upcoming Events
Niagara Region Vegetable Meeting
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August 14, 2024
Clarence Center, NY
We'll start this meeting off at Root Down Farm to hear late season disease management updates in peppers and cole crops, plus current best management practices to limit fungicide resistance. Potato variety recommendations and disease control questions in potatoes will be addressed.
Then we'll head to Kreher's beet field to view and discuss alternative weed control technologies. The beet field is an on-farm demonstration of various flame weeding protocols in comparison with stacked tool cultivation equipment. One or two weeding robots will be on-hand for live demonstrations and discussion of the technology's current abilities and future potential. We'll also cover industry updates and a review of late summer disease management in squash.
2.0 DEC credits will be available in categories 23, 1a, and 10.
2024 Chipping Potato Twilight Meeting
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August 20, 2024
Dansville, NY
Join us for a brief, on-farm meeting including insect pest updates and viewing of the chipping potato variety trial. 1.0 DEC credits in categories 10, 1a, and 23 will be offered. Dinner follows!