UMass twilight meeting 5/19/21 and codling moth management

The UMass Extension Fruit Team will be holding its first-in-a-while IN PERSON Twilight Meeting, May 19, 2021 at the UMass Cold Spring Orchard, 4:00pm-5:30pm. Since this is the first in-person meeting in a while, please bear in mind there will be some new protocols in place. For example, there will be no food available, the University will require masks and social distancing, pre-registration is required and we will be requiring symptom screening. We will be doing our best to make this as smooth a process as possible and are looking forward to seeing you all!

Please use this link to pre-register: https://docs.google.com/forms/inpersontwilight

This warm weather is perfect for plum curculio egg laying activity. Hopefully all RI fruit growers have been able to apply a petal fall insecticide within the last few days to control European apple sawfly and plum curculio.

Codling moth management – Adult codling moths start emerging between McIntosh bloom and petal fall and continue emerging for about 40 days. Peak emergence is usually in late May and female moths start depositing eggs on leaves soon after emerging. Eggs hatch in 7-8 days.

Most insecticides used to manage codling moth are aimed at newly hatched larvae before they enter fruit. The timing for this insecticide application is generally around 2nd cover spray, or 220 degree days (base 50) after McIntosh petal fall. According to NEWA (http://newa.cornell.edu/) we are at about 120 DD in Providence County. Trees in Newport County are a few days behind those in Providence County. This time of year we usually accumulate 10-18 DD each day, depending on temperature.

Insecticides to choose from include Imidan, Assail, Altacore, and Delegate. Codling moths might have some resistance to Imidan, but this has not been documented in our area. A complete list of insecticides for codling moth management can be found on the New England Tree Fruit Management Guide at https://netreefruit.org/apples/spray-table/8-fruit-set-7-14-days-after-petal-fall-apple

Around mid-July, codling moth larvae leave fruit and pupate. Second generation adult moths start emerging in late July and continue emerging through August. Eggs laid by this generation tend to cause more damage than the first generation.

Winter moth caterpillars have been a problem in some Washington County orchards. Winter moths are full grown caterpillars and should be dropping to the ground to pupate in about a week.

We are nearly at the end of primary apple scab season. Apple trees should continue to be protected with a fungicide for another week to protect through the end of primary scab season.

If you need my assistance, please call or email and don’t hesitate to send me pictures.

Heather