Tuesday, May 7: Another Chance For Thinning Applications

If you are not done yet with your thinning sprays and feel that another application is needed, tomorrow, Tuesday-May 7, is another good chance for thinning. Fruit sizes for Gala, Pink Lady and Honeycrisp in Winchester are 12, 12.5 and 10.5 mm which are still within the recommended range for thinning with 6-BA/carbaryl or NAA/carbaryl mixes. Temperatures will drop to 65F this Wednesday making thinning with 6-BA and NAA a bit challenging. The addition of 1 pt/100 gal of oil (e.g. 70-sec superior, JMS Stylet oil) can help increase the response to thinning sprays. However, the addition of oil may cause russeting on some cultivars. Also, Captan should be avoided within 7 days of oil applications, as it may lead to sever russeting. As per the carbohydrate thinning model, the rates of chemical thinners should be increased by 15% for Wednesday applications to compensate for the potential increment in the tree carbohydrate level.

Leave a Reply

Your email address will not be published. Required fields are marked *