May 18, 2018
Strawberries: Crops have advanced quickly this week. Day-neutral strawberries are in bloom and green fruit is present. Bloom has begun in June bearing fields in southern Ontario, both in fields that were row covered this spring and fields that were not. Expect June bearing harvest to begin in a month, day neutral berries in a couple weeks. Bloom is just beginning in eastern Ontario. Row covered fields look good with vigorous growth. Remove row covers soon after flowers appear. Non-row covered fields are slower to get going than we usually see this time of year. Hopefully these fields will catch up with the warm weather this week and next week.
Spring planted day neutrals are beginning to leaf out. Remove the first couple flower clusters until there are 5-6 leaves, to allow the plant to establish before fruit production.
Clipper weevil: clipper weevil can become more active with the warm weather and damage has been seen at a couple farms. You are more likely to see the damage than the actual adult weevil. Look for clipped buds or small round holes in buds or bloom (Figure 1). Continue to monitor throughout bloom. If control is needed, spraying the border rows may provide enough control.
Figure 1. Strawberry clipper weevil damage.
Tarnished plant bugs (TPB): a few adult tarnished plant bugs have been found in strawberry fields. Begin to monitor for TPB using paper plates and tapping the flower clusters onto the plates. Click this link for a video providing more information on TPB scouting. If the threshold (approximately 1 nymph in 4 flower clusters) is reached during bloom or green fruit control is needed. Some group 3 insecticides provide control of TPB and clipper weevil, but can be toxic to beneficial insects. Do not spray when bees are active.
Strawberry Aphids: Aphids are hatching now and populations will begin to increase. Prepare to manage for aphids before and during bloom. Aphid management is important for virus control and we have seen healthier strawberry fields in the last couple years where effective aphid management is in place. Before bloom your options include Cygon, Lagon, group 4s (Admire, Assail), Exirel, Beleaf, and Sivanto Prime. Beleaf can be used once bloom has started. In newly planted fields control aphids with a soil drench of Assail. Check table 3-12, Activity of Insecticides and Miticides on strawberry pests in Pub 360, Guide to fruit protection, to see what activity these products have on other pests. Weekly scouting is important at this time for both TPB and strawberry aphids.
Mites: cyclamen mites can be identified based on the damage. Look for distorted, shrunken leaves and stunted growth. If cyclamen mite has been a problem in the past or you find them in your field, your options for control at this time are Vegol Crop Oil and Agri-Mek SC. Cyclamen mites can be protected in the crown so a high volume spray is necessary to ensure thorough coverage.
Natural predators can be effective at controlling two spotted spider mite and cyclamen mite. Avoid using pyrethroid insecticides (group 3), such as Mako and Matador for TPB and clipper weevil, where cyclamen mite is a problem, as these products are hard on natural predators that help manage cyclamen mite.
Anthracnose and botrytis: It is important to think about disease control during bloom, especially if you are expecting rain this weekend. Disease pressure is highest during warn, rainy weather during bloom, similar to the forecast. Pristine (7+11), Cabrio (11), and Switch (9+12) are registered for control of anthracnose. Anthracnose resistance to group 11s has been identified in Ontario. Tank mix Pristine and Cabrio with a group M for botrytis control to avoid developing resistance. Avoid working in fields when they are wet.
Blueberries: are at flower cluster and quickly approaching bloom in southern Ontario, bud swell in eastern Ontario. The crop is looking promising. Evaluate your plants now and your pruning practices for next year; a balance between vegetative growth and fruit production is important.
Disease: bloom is an important time for disease control.
- Mummy berry: Blueberries can be infected with mummy berry shoot blight at the bud burst stage. Control for mummy berry beginning at bud swell through early bloom if there is a history of mummy berry on your farm. Mummy berry infections occur after 6 hours of rain or more depending on temperature.
- Use fungicides from different groups to control cane diseases such as phomopsis and anthracnose twig blight. Bravo can be used until petal fall.
- Use fungicides that control both botrytis and anthracnose fruit rots during bloom
Insects: Check for scale insects on branches. Use black sticky tape to identify when crawlers are active. Cranberry fruitworm and cherry fruitworm begin to fly at bloom. Wait to apply insecticides until petal fall.
Raspberries: are leafing out and flower buds can be found on overwintering canes. Primocanes are emerging in southern Ontario.
Disease: It is important to protect growing primocanes and developing laterals from cane diseases with fungicide applications before and during bloom. Ferbam (before bloom only) and Tanos are 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. Apply Ferbam and Tanos when there is 25-30 cm of new growth. Good coverage is important.
Insects: Begin to monitor for raspberry fruitworm and strawberry clipper weevil once fruit buds are present.
Diazinon 500 E is registered for control of Raspberry crown borer for one application only, when new canes reach 10 cm.
Haskaps: haskaps are in full bloom
- Blueberry IPM workshop. Wednesday, May 30th. 1283 Blueline Rd, Simcoe, Ontario. Minimum ten participants.
These workshops are free. Handouts are provided. Bring your own lunch. To register contact OMAFRA’s Agricultural Information Contact Centre at 1-877-424-1300.