VT Apple IPM: NEWA is down temporarily

Good morning:

The NEWA system that most of us rely on for pest models and forecasting is not importing data from any stations right now because the data centers at the National Weather Service that process the data are experiencing outages. Until it is back up, we’ll need to rely on some rules of thumb to manage apple scab, which is the only real IPM issue of immediate concern right now. We can assume that all orchards except maybe those in the coolest inland/upland sites are in the accelerated scab phase. That means keeping covered with a protectant fungicide (mancozeb for most, sulfur for those managing organically) before every rain, and adding a material with postinfection activity if you think that coverage was questionable going into a wetting event. As they work better in cooler weather and have little activity against fruit scab so are of less use postbloom, Vangard or Scala (FRAC class 9 Anilinopyrimidine fungicides) are good choices.

I just posted a video yesterday on hanging tarnished bug traps to start the monitoring season. For most orchards that sell fruit direct to consumers I don’t worry too much about this pest, but they can cause substantial damage to wholesale-marketed fruit and to peaches. The trap is the same as that used for European apple sawfly, which we’ll hang in a couple of weeks and can be more damaging. Many here know that I am generally not a fan of prebloom insecticides for most Vermont orchards, but they can be an important tool in some situations. I’ll be including regular monitoring updates this season to help you to implement scouting on your farm.

On a similar note, a grower sent me pictures of aphids in their apple buds the other day. It is a bit early to see them, but I advised to wait and watch before taking action. Strating off with insecticide treatments this early in the season is a sure way to throw orchard ecology out of balance and favor secondary pests like mites and aphids that would be controlled by predator insects and allow them to become season-long pests.

More to come, and please keep and eye on https://newa.cornell.edu/, as I am sure it will be back in operation soon.



Terence Bradshaw (he/him)
Associate Professor, Specialty Crops
Interim Chair

Department of Plant and Soil Science
College of Agriculture and Life Sciences

University of Vermont
117/210 – Jeffords Hall | 63 Carrigan Dr
Burlington, VT 05405

(802) 922-2591 | tbradsha

Information for commercial orchard and vineyard managers in Vermont and beyond:

UVM Fruit Website | UVM Fruit Blog
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