May 17 Berry Bulletin

Strawberries:

Berry crops continued to move quickly this week, and growers are busy planting. There is a lot of bloom in early and mid-season June-bearing strawberries in southern Ontario. Green and ripening berries can be found in early June-bearing fields, and day-neutrals are ripening quickly. Insect pressure continues to increase. Watch for aphids, tarnished plant bug, thrips, potato leafhoppers and mites.

• Aphids:  Many June-bearing fields have had an aphid product applied- if you have not been monitoring for aphids a spray is likely needed at this point. Aphids need to be managed approximately every 3-4 weeks. Beleaf or Sivanto Prime can be applied during bloom if needed.

• Tarnished plant bug: nymphs are easier to find now. The threshold for control is approximately 1 nymph in 4 flower clusters. If an insecticide is needed Beleaf applied at the high rate during bloom will suppress TPB and control aphids.

• Cyclamen mites: As June-bearing fields continue to fill in look for areas with weak, stunted growth and toughened, distorted leaves. Look at the youngest leaves for mites inside the folded leaves. Pay close attention to areas that were row covered and fields with a history of cyclamen mite in both June-bearing and day-neutral fields. If cyclamen mites are identified apply Agri-mek at 225 mL/ha in a high-volume spray (minimum 375 mL/ha), with a non-ionic surfactant at 0.1-0.5%, where permitted. It is very important to get thorough coverage- slow down and use a high volume. Agri-mek can only be used twice a year. Avoid applying Agri-mek during bloom.

• Disease management: Disease prediction models are available this year to help with controlling anthracnose and botrytis. There is a high risk of anthracnose and botrytis infection in some parts of the province this weekend. See the 2024 Strawberry Disease Decision Support System for more details. For June-bearing strawberries spraying for anthracnose after bloom is only needed if warm, wet weather conditions are present.
• For day–neutral fields, use a group M during bloom for broad spectrum disease control, up to 6 days before harvest. Once harvest begins Switch/Button (9+12) and Miravis Prime (7+12) are the most effective products. Keep in mind there is a maximum 3 applications of Switch/Button per year and 2 applications of Miravis Prime per year. Do not make more than 3 applications of fludioxonil-containing products per year (Switch, Button, Miravis Prime, Scholar).
• Angular leaf spot can be found in June-bearing fields. Check the underside of older leaves for angular, dark green lesions. This bacterial disease will spread by rain or irrigation. Use Tivano for leaf spot suppression.  

Blueberries:

Blueberries are in full bloom in southern Ontario and full of bees. If rainy weather occurs during bloom, fungicides will be important for anthracnose and botrytis fruit rot control. This is also a good time to control Phomopsis.

• Cranberry fruitworm and cherry fruitworm: Petal fall applications of an insecticide can be timed by using pheromone traps or degree day models. Otherwise, plan to apply 1-2 insecticides at petal fall.

Raspberries:

Plenty of raspberry fruit buds can be found and primocanes are 10-12” tall. Insect pressure has been low but watch for raspberry fruit worm and clipper weevil.  If there are no signs of beetles or leaf injury an insecticide is not needed until after bloom.

• Protect growing primocanes and developing laterals with fungicides before and during bloom.

Have a great long weekend!