My longtime colleague and predecessor in this Extension role, Lorraine Berkett, always used to stress that “the growing season starts April 1”. By that she didn’t mean that we should be firing up sprayers by April Fools’ Day— although in one year I did make my first copper application to the orchard on March 30— but rather that we should have our ducks in a row and be ready for active management by the beginning of the month. The Second False Spring of last week has led to Fourth Winter this week, but the trend is looking like we’re heading for a ‘normal’ spring wakeup, so a ‘ready by April’ warning is still in-play.
I am writing a joint orchard-vineyard bulletin today because the things we need to consider are largely the same at this time of year. Pruning should be wrapping up in apples, and it’s time to push out or better yet flail mow prunings to facilitate sprayer and other equipment access. There’s still time to prune grapes, and peaches should be pruned during bloom so you’re looking at May for those if you have them. Where possible, I prefer to flail mow prunings and leave the debris in the orchard, as that is organic matter that is valuable for soil health and I am not convinced that, as long as debris is sufficiently shredded, that it contributes to disease inoculum. One exception may be in orchards that have more than incidental fire blight. If you don’t have a flail mower, the brush is too big to go through the mower, or you are concerned about disease inoculum, then you may push brush into the burn pile and deal with it that way. Whatever you do, it needs to get out of the way soon.
Once the brush is out of the way, or even with it on the ground if it’s small stuff, it is good to make a final pass with the flails set real low to shred leaf and other debris to reduce disease inoculum and overwintering insect pests. This can produce measurable decreases in apple scab and grape black rot inoculum that can make you early season disease management much more effective. Another option is to apply a urea solution (UMASS recommends 44 lb urea in 100 gal of water) at a rate of 100 gallons per acre to the orchard floor, being sure to spray into the tree row where it can be hard to mow the leaves. Good orchard sanitation and a scab-free season the year before can allow growers to delay the first one or two scab sprays.
Sprayers should be brought out tested, calibrated, then re-winterized to be ready for first applications of the season. In apples, we’ll be putting on oil and copper in the next couple of weeks. In grapes, growers may consider applying lime sulfur to pruned dormant vines to reduce overwintering disease inoculum. I’ll have details on both of those practices as the need gets closer.
In the Champlain Valley, fields can be prepared for planting this spring. We are installing a new orchard at UVM HREC later in April, and have a field that we plowed and harrowed last fall to incorporate cover crop, and are in the process of liming and discing to adjust soil pH and build up calcium levels that will be necessary for optimal (and bitter pit free) fruit production.
Scouting season is almost here in Vermont orchards. We have some funds available to distribute traps to growers around the state to help track pest incidence and better guide our recommendations to growers. If you are interested in contributing to the scouting program, fill out this interest form at here: https://forms.office.com/r/7QRfXfHqsd
I look forward to working together for another season.
-Terry
The UVM Tree Fruit and Viticulture Program is supported by the University of Vermont Agriculture Experiment Station, UVM Extension, USDA NIFA E-IPM Program, and USDA Risk Management Agency.
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