In this bulletin:
- Crop Update
- Spotted wing drosophila monitoring
Strawberries:
Growers continue to harvest Malwina while renovating the earlier varieties. Check out the July 2nd bulletin for more details on renovating. Renovate as soon as possible to help manage SWD. Make sure to look for cyclamen mite injury in the fields you are renovating to determine if Agri-mek is needed after mowing.
Over-wintered day-neutrals are being picked again. Spring-planted day-neutrals are at the bloom-green fruit stage and picking will begin in a couple weeks. As day-neutrals continue to bloom and ripen it is important to maintain fungicide coverage for botrytis, anthracnose and powdery mildew. Now is a good time to apply captan/Maestro on your spring-planted day-neutrals. There is a 6 day REI for captan so use it now before harvest. Once harvest begins rotate between Switch, Diplomat and Quadris Top for anthracnose control.
Tarnished plant bug: Day-neutral growers need to monitor for tarnished plant bugs now.
- Rimon and Beleaf are good options for TPB as they are easy on beneficial insects but they do not provide much, if any, activity on SWD.
- Cormoran is registered for TPB control with a 1 day PHI and will also provide control for SWD, aphids, and leafhoppers.
- Also monitor for two-spotted spider mites and potato leafhoppers in day-neutrals.
Strawberry Aphids & Virus: An insecticide needs to be applied every 2-4 weeks for aphids if you are not monitoring the population. It is very important to control aphids in new plantings as well- there is a low tolerance for aphids in new fields.
- If there are 15 aphids on 60 leaves apply an insecticide.
- Bearing fields will need an insecticide after mowing and new growth has emerged.
- In new fields choose products that will control aphids and leafhoppers, such as Sivanto Prime, Assail, Cygon or Lagon.
Raspberries: harvest continues, and the crop is looking good.
- Growers should be spraying for SWD regularly, which can be challenging to maintain with the regular rains. Choose products with good rainfastness. The most rainfast SWD products for raspberries include Exirel, group 5s (Delegate, Entrust, Success), and group 3s.
- Japanese beetles are also showing up in raspberries- Exirel or Malathion applied for SWD will also help control Japanese beetles.
- Potato leafhoppers are causing leaf yellowing and curling in raspberries. Control may be necessary if there are 1-2 nymphs per leaf.
Blueberries:
With harvest ongoing SWD needs to be managed weekly from this point on. Japanese beetles may also need to be controlled in blueberries- Cormoran, Altacor and Exirel are registered for control. Note that Cormoran has an 8-day PHI. Exirel will be a good choice as it will control SWD as well.
Spotted Wing Drosophila:
SWD has been caught in Essex, Elgin, Norfolk, Haldimand, Middlesex, Oxford, Niagara, Halton, Hamilton, Hastings, Prescott & Russell, and Renfrew county.
Berry crops with ripe fruit are now at risk, and all growers should maintain a regular spray program if there is ripe fruit on your farm, including in day-neutral strawberries, summer-fruiting raspberries, and blueberries.
Use as many of these tools as possible through the season to control SWD:
- Spray every 5-7 days. A list of registered products is attached.
- SWD prefers moderate temperatures and humid conditions. SWD numbers could build up quickly in these conditions and it is very important to maintain insecticide coverage.
- 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. Cormoran is registered for SWD control on blueberries (8 day PHI) and on strawberries for aphids and TPB.
- Reapply after ½ inch of rain. For more information on the rainfastness of insecticides check out this article from 2020: https://onfruit.ca/2020/07/14/rainfastness-of-insecticides-on-fruit-crops-2020-a-reprise/
- 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 (Mako, 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!
- 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 to ensure excellent coverage once you start to spray.
- Renovate June-bearing strawberries as soon as possible. Do not leave overripe strawberries in the field; SWD populations can build up in this leftover fruit.