June 7, 2020
I had a chance to visit some orchards late last week in Southern Vermont. We should remember that the lower Connecticut River Valley has traditionally been a major center of apple and peach production in the state. While there are fewer acres of trees than in the past, that’s true across the state. I am always impressed by the landscape down there, it really feels like another place compared to the Champlain Valley or interior highlands. What I saw is likely pretty indicative of orchards around the state.
Fruit set looks pretty heavy, and I have been seeing evidence of thinners applied early last week working. We are entering another window of good thinning weather, so if your crop id still clustered into doubles and triples per cluster (or worse), plan on another thinner this week before it warms up again. Grower who use Apogee for shoot growth management should keep applying on a 10-14 day schedule until terminal bud set. That’s still a solid month away. Get your nitrogen, potassium, magnesium, and boron fertilizers (plus anything you need if your foliar analysis from last year indicates it) on now. Any time, you can start applying calcium sprays to developing fruitlets, especially Honeycrisp and other large-fruited varieties.
Diseases: scab? What scab? This spring has been easy to manage for apple scab, as rains have bee intermittent, spread out, and fairly short. NEWA suggests that most of the ascospores at our orchard in South Burlington have been ejected, but I don’t really trust that yet. Growers should maintain fungicide coverage ahead of any rain events for the next couple of weeks. Fire blight: I started seeing symptoms on Friday in one of our blocks that was intentionally inoculated as part of Dr. Kerik Cox and Anna Wallis’s fire blight trials I am hosting. So, I know conditions were ripe for infection. Keep an eye out in your orchards and be ready to cut out any strikes as they appear. Haste is good on that front. Sooty botch / flyspeck will be managed with your scab sprays.
Insects: Things are hopping on that front. Plum curculio remains active and I have seen injury. We’re only about halfway through their oviposition period at this point, so keep covered. Organis corchards should plan to keep Surround on for another couple of weeks anyway. Codling moth are active. If you didn’t trap them in your orchard, use the NEWA models to guess, but it’s always best to use an actual catch date from your farm when calculating degree days for managing this pest. I’ve played around with a few capture dates for various orchards in the warmer sites and all are calling for treatment sometime this week. If CM are a problem in your orchard, I would plan on a spray specific to them with a selective and efficacious material like Intrepid, Rimon, Belt, or Madex. As always, see the New England Tree Fruit Management Guide for recommendations.