In this bulletin:
- Crop Update
- Spotted wing drosophila
- Strawberry Disease Decision Support System
Strawberries: After a wet weekend and week in some parts of the province growers are moving on to late varieties including Valley Sunset and Malwina. Pick-your-own is slowing down and wrapped up in some areas. Botrytis, anthracnose, and sunscald can be found from the recent wet and hot weather.
Renovate as soon as harvest is over to help manage SWD- do not wait for late varieties to be harvested to renovate earlier blocks. See below for SWD update.
Renovation includes applying fertilizers, narrowing rows, mowing, and herbicide applications. After mowing apply 50 kg of N per hectare along with other nutrients if needed. The earlier renovation can be completed the better. Broadleaf herbicide options include 2,4-D amine or Lontrel XC/Pyralid. 2,4-D amine should be used to control broadleaf weeds including dandelion, daisy fleabane, and annual seedlings. Wait 2-3 days after applying 2,4-D amine to mow the strawberries. Lontrel XC or Pyralid can be used to control broadleaf weeds including wild buckwheat, daisies, nightshades, Canada thistle, and vetch. Wait 7-10 days after applying Lontrel or Pyralid before mowing. Grass herbicides should be applied separately from these herbicides.
If Agri-mek is needed after renovation for mite control:
- Apply Agri-mek at 225 mL/ha in 750-1000L water /ha, with a non-ionic surfactant at .1-.5%
- Watch the pH of your spray tank.
- Slow down and get thorough coverage of the plants and crowns- this is very important!
- Apply Agri-mek under slow-drying conditions to improve uptake into the leaves.
- Agri-mek can only be used twice a year.
- Do not apply sinbar after applying Agri-mek. Wait 5-7 days after Agri-mek before applying sinbar.
New fields: are looking good. Check for aphids and leafhoppers in new fields. Cygon, Lagon, Cormoran, and Assail applied for aphids will provide some control of leafhoppers as well, so these could be a good choice if both pests are present
Day-Neutrals: If harvest hasn’t started yet now is a good time to get a group M fungicide (6 day REI) on for disease control and resistance management. The Strawberry anthracnose management suggestions have been updated. Note that there should only be 3 uses of fludioxonil-containing products (eg. Switch, Button, Miravis Prime, Scholar).
Day-neutral growers should also check out the strawberry disease models that are now available. See more information below.
Raspberries: Raspberries are being harvested across the province, and the crop is looking good. Watch for potato leafhopper in new fields and fall-bearing raspberries. Japanese beetles also started to show up this week. Growers should start planning to control for SWD. Keep your fields picked clean and cool fruit after harvest.
Spotted wing drosophila monitoring: Spotted wing drosophila traps have been set up in Norfolk, Elgin, Middlesex, Chatham-Kent, Oxford, Niagara, Waterloo, Wellington, Dundas, and Renfrew. It is important for growers to monitor on your own farm ; to monitor you can use sticky cards to identify adults, or salt water tests or plastic baggie tests to monitor for larvae. The first SWD were found this week; 1 SWD was caught in four counties.
Summary of SWD trap catches:
Week traps collected
County/region where SWD was found
Crops where SWD was trapped
Elgin, Oxford, Waterloo, Middlesex
Wild hosts, currants
This monitoring is funded by the Berry Growers of Ontario. Thanks to the growers, consultants and OMAFRA staff helping with this monitoring!
Once SWD is active in your area and ripe fruit is present regular sprays are needed, depending on crop stage. Do not count on sprays alone– use as many of these tools as possible through the season to control SWD:
- Spray every 5-7 days.
- Using the best products first will help knock the population back down at the beginning of the season. The most efficacious products include Exirel, Delegate, Success, Harvanta and Cormoran.
- Reapply after ½ inch of rain.
- Use products from different groups.
- Spray in the morning (6-10am) or in the evening (6-10 pm) when SWD is active.
- Do not spray in temperatures above 25C.
- Pyrethroid insecticides (Up-Cyde) will not work well in hot weather and will cause an increase in mites. Save these products for later when weather cools off and mite pressure is low.
- Keep your fruit picked regularly and clean- this can be very effective!
- Cool fruit immediately after harvest.
- Keep alleys clean- either remove unmarketable fruit or crush it in the alley
- After unmarketable fruit is removed it should be destroyed (disposed of, or leave in plastic bags in the sun).
- Make the environment less favourable to SWD- prune the canopy and manage water to reduce humidity (repair leaking drop lines).
- Calibrate your sprayers now to ensure excellent coverage once you start to spray.
- Renovate June-bearing strawberries as soon as possible.
Strawberry Disease Decision Support System now available
This season strawberry disease prediction models are available for Ontario growers to access to help assess the risk of anthracnose and botrytis from bloom to harvest.
OMAFRA has partnered with Weather Source to provide OnPoint Weather. The locations on the map are based on agricultural production and use all nearby weather data and geography to provide accurate forecasting data. At the end of the season, OnPoint Weather data will be compared to on-farm weather station data to assess predictive accuracy.
The Strawberry Diseases Decision Support System can be found on the ONfruit blog under the ‘Berries’ tab, or you can bookmark this page: 2023 Strawberry Disease Decision Support System. The Strawberry Diseases Decision Support System includes a map indicating fruit infection risk across the province and a graph tracking risk through the season.