As the weather has warmed up, most grape varieties are at or past early bud swell. Juice grapes and early hybrids are at full bud break with first leaves starting to fold out. Other hybrids and early vinifera varieties have opened up, but leaf material is not yet visible. Dormant pruning should be ending.
The disease focus at this time is on phono-sis, black rot, anthracnose and powdery mildew. With the mild winter, expect high levels of surviving inoculum on shoots, dried clusters and canes. A dormant spray in the fall or spring can help manage them before the season starts. Once leaf tissue is visible, contact fungicides that include broad-spectrum or contact fungicides like the EBDCs (FRAC M3) and captan are effective and function similar to dormant applications by sanitizing the vineyard before bloom. Organic growers can use early season oils, which try to suffocate overwintering fungal spores and infected tissues. Be careful of utilizing oil applications within 14 days of any sulfur application due to phytotoxicity issues.
Our regular southwest Monday fruit IPM updates are once again a hybrid format. The meetings are held in-person with virtual attending also available online. Our first meeting was Monday, April 10, at 5:30 p.m. and will continue through the rest of the season. You need to register to receive the Zoom link and password for these meetings. The webinars are free and one pesticide applicator credit is available for each meeting. The same Zoom link will be used with all the Monday meetings—you only need to register once. Before the meetings, Cheyenne Sloan will have Fruit Spray Guides for sale on April 21 and will have forms available for tax-exempt individuals for receiving a reduced price.
Derek Plotkowski, the fruit educator in southeast Michigan, is organizing an Orchard and Fruit Production Classifieds & Exchanges service. Looking for something that you can’t get ahold of in time? Maybe one of your neighbors has some on hand. Have extra of something you’d like to offer? Fill out this form and we’ll add your needed or extra items to the Orchard Classifieds/Exchanges list. The items currently on the exchange can be found here: Orchard Classifieds and Exchanges. — By the Michigan State University Extension