April 3, 2020
Contact Information:
Peter Werts:
John Aue:
Josie Dillon:
AppleTalk call and blog logistics
Thank you for registering for AppleTalk! Your participation makes this program possible. After each AppleTalk, you can expect the call recording and agenda to be posted to the blog following the call. Written summaries will be posted when complete, within 24 to 48 hours, and distributed via email in PDF format. John Aue, Peter Werts and Josie Dillon are available to answer questions as the season begins.
If you still need to register for AppleTalk visit: https://ipminstitute.org/projects/specialty-crop-grower-services/appletalk/register/.
Regional Update
Most locations are between 20 and 40 degree-days base 43°F. We are currently behind Michigan where they are at bud swell with some silver-tip on Ginger Gold. Many Michigan growers will be applying copper within the next week or so. Growers should expect some bud swell by this weekend and copper may need to be applied the week of April 8 if temperatures are consistently warm. Locations that are further north, e.g., Chippewa Falls, Hastings, etc., will likely be further behind.
| Location | Degree Days 4/02/2020 (Base 43°F) | |
| Eau Claire, WI | 22 | |
| Gays Mills, WI | 26 | |
| Hastings, MN | 24 | |
| Harvard, IL | 27 | |
| La Crescent, MN | 30 | |
| Lake City, MN | 20 | |
| Mauston (Northwoods), WI | 22 | |
| Mequon (Barthel), WI | 14 | |
| Preston, MN | 21 | |
| Rochester (Ela), WI | 26 | |
| Trempealeau (Eckers), WI | 30 | |
| Verona, WI | 15 | |
| White Bear Lake, MN | 22 | |
| Woodstock, IL | 38 |
Table 1. Accumulated degree-days base 43°F as of April 2, 2020.
NEWA weather stations
The Network for Environment and Weather Applications (NEWA) weather stations provide forecasts and historical weather data for around 20 weather station across IL, MN and WI. Visit the links below to see if there is a station near you. The NEWA site offers a friendly interface to monitor insect and disease development and access crop management tools. Access to the site is free of charge and you don’t need to have a station to use this resource. This is a resource that we will be using and referencing season long. If you have any questions with accessing a station please contact Peter, Josie or John. Access your local station here:
Wisconsin – http://newa.cornell.edu/index.php?page=station-pages-wi
Minnesota – http://newa.cornell.edu/index.php?page=station-pages-mn
Illinois – http://newa.cornell.edu/index.php?page=station-pages-il
Copper and oil
At bud break, use 2 lb. of actual metallic copper per acre and apply with a high volume of water, e.g., 75 – 125 GPA, depending on tree size. This would equate to seven pints of Badge per acre, four pounds of C-O-C-S per acre or 6.7 pounds of Kocide 3000 per acre. Kocide 3000 and Badge are more expensive products and are a finer ground material which will last longer. A 1% concentration of oil can be used to improve the distribution of the copper within bark and cankers. This helps to distribute the copper to break surface tension. Oil should be applied at temperatures 60°F and above. To reduce risk of bud damage, do not apply oil when temperatures have been, or are forecasted to be, below 32°F within 48 hours of the application. As temperatures increase, overwintering mite and San Jose scale respiration rates increase and the oil application will do a better job at suffocating mite eggs and San Jose scale.
