2019 Fruit Pest Update
July 8, 2019
7/10/19 Update: SWD ALERT!!
One spotted wing drosophila female was caught in three different traps in different orchards in Southern Door this week. Cherries are susceptible to damage starting at straw color.
Growers are advised to begin 7 day full cover control applications through harvest.
7/12/19 Update– a total of 20 SWD were caught this week, all in Southern Door. Still 0 caught in Northern Door.
Things are definitely moving along. Early sweet cherry harvest will start next week. Most tart cherries are at the straw colored stage and grapes are at late bloom to buckshot stage.
NOTE: The Enviroweather Stations are going through an upgrade, so you might see some temporary outages over the next week or two. We are working to get them back online as quickly as possible.
Below is a degree day comparison of the last five years.
|Date 7/8||2015||2016||2017||2018||2019||5 yr avg|
INSECT & DISEASE CONTROL
Disease Pressure – It is safe to say that primary apple scab season is over. Continue to monitor blocks, but if control was good so far, sprays can be stretched to 2-3 week intervals. Apple growers who have scab lesions present in their orchards should continue to apply protectant fungicides on a shorter interval of 10-14 days. Powdery mildew pressure is increasing, especially with dry, humid weather and warmer temperatures. It hasn’t been detected yet, but scout for dusky-looking, stunted terminal leaves. Fireblight strikes still haven’t been detected, but there is still the potential for infection, especially with warm temperatures and if there is hail or damaging winds. Sooty blotch and flyspeck is starting to show up (see article from the Wisconsin Fruit News at the end of this report).
Insect Pressure – First generation codling moth is at peak flight. We are past the 250 GDD window since biofix (June 29) when the first spray should have gone out. A follow-up application should go out 10-14 days after the first spray. Adult plum curculio activity is primarily over. Apple maggot traps will be set this coming week. Rosy apple aphid and woolly apple aphid may be showing up in the lower, interior, part of the canopy. The best time to control these pests is at pink, because it is nearly impossible to get good coverage at this time.
Disease Pressure – – Cherry leaf spot pressure remains very high and it is important to stay on a tight spray schedule. Secondary infections are going to continue to be a threat especially in blocks that did not have good early control. Some powdery mildew is showing up in more sheltered blocks, with less airflow. If present, make sure to use products labeled for powdery mildew control, rather than relying only on Captan or a protectant-only spray program.
Insect Pressure – No SWD has been caught in any of our traps yet, but numbers are starting to slowly increase around the state. Based on what we’ve seen in the past few years, we are expecting a drastic increase in numbers in the next couple weeks, which could mean high numbers at cherry harvest. Tart cherries in most blocks are straw colored, so they are susceptible to SWD damage once they begin to emerge. No cherry fruit fly have been caught. Once cherry fruit fly become active, an insecticide should be applied within one week of a catch on yellow sticky traps. Continue to scout for European red mites, especially in blocks where there has been a lot of use of pyrethroids for SWD control in the past few years.
Celebrate the first Wisconsin Vineyard Week by coming to the Peninsular Agricultural Research Station Vineyard Walk! Please RSVP to Anna Maenner with the WGGA (firstname.lastname@example.org) or to the Door County Extension Office, 920-746-2260.
Disease Pressure – Disease pressure is high and will remain high with humid weather. Many foliar diseases are present and fungicide programs should continue. If bunch rot has been an issue in the past, an early fungicide now, while fruit clusters are still open, can help combat this disease. When scouting for diseases, former UW graduate student, Dave Jones, made an excellent photo disease guide per variety that can be found here: https://fruit.wisc.edu/wp-content/uploads/sites/36/2017/04/Photo-guide-diseases-cold-climate-grape.pdf.
Insect Pressure – Continue to prune out grape tumid gallmaker galls if found. Rose chafer are showing up in the vineyard block at the Peninsular Station. These beetles are most common in sites with sandy soil and the adults will remain active for three to four weeks. Here is a link to an article from Michigan State about controlling rose chafer: https://www.canr.msu.edu/news/rose_chafer_management_for_vineyards
Wisconsin Fruit News: **New Issue this Week**
Wisconsin Fruit News Vol. 4 Issue 7 (July 5, 2019)
Plant Disease Diagnostic Update
Insect Diagnostic Lab Update
Apple Sooty Blotch and Flyspeck
Black Stem Borer
Strawberries Post-Harvest: Renovation or Rotation?
Grape Variety Developmental Stages
Grape Scouting Report: Grape Phylloxera or Grape Scale?
Door County Report
WFN- Vol. 4, Issue 6 (June 21, 2019)
- Governor Evers Declares Wisconsin Vineyard Week, July 14-20
- Grape Scouting Report: Low Insect Pressure
- Grapevine Phenology for Mid-June
- Promoting Return Bloom in Apples
- Some Cold, Hard Facts about Winter Injury on the First Day of Summer
- Door County Report
WFN-Vol. 4, Issue 5 (June 7, 2019)
- Strawberry angular leaf spot
- Grape downy mildew
- Chlorpyrifos update
- Apple thinning update
- Door County Report
WFN-Vol 4, Issue 4 (May 24, 2019)
- Risks and benefits of reducing herbicide rates
- Winter damaged blueberries
- Eastern berry thrips
- Bitter pit management
- Door County Report
Links to individual Enviro-Weather stations: