Notes from the Field: A Grower’s Perspective – Chris McGuire Chat #3
I had my third chat with Chris on May 28…
Recent weather events, including heavy rainfall and a damaging hailstorm, have impacted operations at Blue Roof Orchard. Chris has seen 3.5 inches of rain over 5 days during this last week. Adding to the challenge, is last week’s hailstorm, with golf ball-sized hailstones, caused substantial damage to the orchard. The hail has wounded branches and leaves and pulverized many of the developing fruits. At this early stage, the fruits are still small targets and not all were damaged, so there is an opportunity for selective removal during fruit thinning.
Chris hadn’t done any hand thinning before the hail hit, so they can now remove the unmarketable fruits as part of the thinning process. Given these circumstances, Chris is considering the installation of hail netting. While many growers use a drape net that covers the tree rows, extensive hand work and regular orchard operations make this a challenging option to implement. Some netting options are suspended above the trees and still permit regular orchard operations, however these options come at a greater cost.
A few fire blight strikes have been detected following the hailstorm. Unfortunately, they were not noticed earlier, increasing the risk of potential pathogen spread during the storm.
Typical weekly pesticide applications have faced the challenge of being washed off due to the persistent rain. Chris is using Surround and Grandevo insecticides to manage plum curculio, while scab and cedar apple rust are no longer concerns. The focus is now shifting to managing summer fruit rots and sooty blotch and flyspeck (SBFS). For these diseases, Chris uses Lifegard + Carb-O-Nator.
To prevent bitter pit, Chris applies calcium chloride every ten days. For codling moth Chris uses mating disruption and will spray granulosis virus; no codling moths have been caught yet in monitoring traps. For the first time at Blue Roof Orchard, they have installed mating disruption for the dogwood borer, noting an increasing presence of these insects over the last few years. Unfortunately, there are no effective organic pesticide controls for dogwood borer.
To continue to manage the weeds, Chris has spot-treated the orchard with Homeplate herbicide. This timely application, while the weeds are still relatively small, has been cost-effective and efficient, reducing hand weeding. Chris notes that maintaining a low pH in the tank is important for the efficacy of the herbicide. Previously, they used a backpack sprayer for herbicide applications, but the lack of tank agitation led them to switch to a tractor-mounted sprayer. The mulch they use in the orchard continues to be effective in suppressing weed seeds below the mulch surface, but Chris emphasizes that the mulch does not help suppress any weeds with seeds that land and germinate on top of the mulch, and in this scenario, herbicides are still necessary.
That’s all for now! Check out the notes from my next chat with Chris in two weeks on June 19. If you missed my previous chat with Chris, check it out here.
This article series is NOT intended to be prescriptive for other orchards. It is simply an opportunity for our readership to hear from other growers about their experiences growing fruit crops in Wisconsin.
Growing the same crop does not always justify the same practices. Management decisions at your farm should be tailored to your operation and consider location, regional climate, disease and pest history of your vineyard, and your varieties.
The mention of a product is NOT an endorsement. Always follow the instructions on product labels and consult weather stations (ex. NEWA) in your area for current weather forecast and disease and pest prediction models.
Additional readings for topics discussed in this article:
- https://fruit.wisc.edu/?s=dogwood+borer
- https://fruit.wisc.edu/2021/08/19/apple-summer-rots-and-sooty-blotch-flyspeck/