Crop Update

Strawberries

Growers were frost protecting again on the morning of the 20th, followed by a cool and very wet week this week. There is a lot of bloom in early and mid-season June-bearing strawberries in southern Ontario. Green fruit and bloom can be found in early, row-covered June-bearing and day-neutrals fields.

Disease

• Bloom is an important time for disease control. Use broad spectrum fungicides (group M) during bloom as much as possible for botrytis control (June-bearing and day-neutrals). Reapply if needed after an inch of rain.
• Our Suggestions for Anthracnose Management have been updated for the 2025 season.
• Additionally, the Strawberry Disease Decision Support System is now running for the 2025 season. Use the disease prediction models to time fungicide applications for anthracnose and botrytis.
• Angular leaf spot can be found in some June-bearing fields. Check the underside of older leaves for angular, dark green lesions. This bacterial disease will spread by rain or irrigation. Tivano can be used for angular leaf spot suppression. Do not use a surfactant with Tivano when angular leaf spot is present.

Insects

• Small tarnished plant bug(TPB) nymphs are easier to find this week- the threshold for TPB is roughly 1 nymph in 4 flower clusters. If an insecticide is needed Beleaf applied at the high rate (200 g/ha) during bloom will suppress TPB and control aphids.
• Aphid pressure is variable depending on where insecticides have been applied. Consider applying an insecticide for aphids where nothing has been applied yet.  Aphids need to be managed approximately every 3-4 weeks. Beleaf or Sivanto Prime can be applied during bloom if needed.
• Low numbers of thrips are beginning to show up in strawberry fields. Thrips can cause bronzing under the calyx and on the fruit, and can cause the entire berry to become bronzed and cracked. To check for thrips blow gently on strawberry blossoms to encourage thrips to move out of the bloom (Fig.1). Thrips are small, thin, thread-like insects. Exirel, Delegate, Harvanta and Beleaf are registered for thrips control or suppression. The Beleaf rate for thrips is 200-300 g/ha, with a maximum 600 g/ha of Beleaf per season.

• Where cyclamen mite has been found it is a good time to apply a miticide in mid- and late- season June-bearing varieties before bloom is present and damage to blooms can occur. Cyclamen mite can damage blooms and result in small, cracked and seedy berries. Agri-mek and Magister are both options for cyclamen mite control this year. It is very important to get thorough coverage for both products- slow down and use a high volume. Avoid applying either product during bloom. See last week’s bulletin for more details on miticide applications.  

Blueberries

Blueberries are in bloom across the province. If applying nitrogen in split applications, plan another application of 12-18 g of N per bush at petal fall. A total of 36-48 g N/bush should be applied each year to established plants.  

• Disease: With the rainy weather this week fungicides are important during bloom for anthracnose and botrytis fruit rot control. This is also a good time for Phomopsis control. Fungicide options are listed on the Ontario Crop Protection Hub. Rotate with different fungicide groups.
• 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

Raspberries are beginning to bloom in the earliest areas with plenty of fruit buds present in the rest of the province, and new primocanes are 8-10” tall.

• Insect pressure has been low but watch for clipper weevil and raspberry fruitworm.
• Protect growing primocanes and developing laterals with fungicides before and during bloom. Tanos is registered for cane diseases, but Pristine and Switch also do a great job on cane diseases when they are used to control Botrytis grey mould. Good coverage is important.