July 6, 2018
This week’s update:
-Spotted wing drosophila
Strawberries: After a hot long weekend harvest continues but is slowing down for June bearing strawberries. Valley sunset continues to be harvested, and the first Malwina are being harvested in southern Ontario and are ripening in other areas. Growers are beginning to renovate their early varieties. It is a good idea to mow your early varieties as soon as harvest is done. As we begin to manage for SWD in late varieties and other berry crops don’t forget about cyclamen mites. If you had damage from these mites this season you will need to manage for them shortly after renovation.
Mites: cyclamen mites were a challenging pest this year for many strawberry growers across the province. Renovation is the time to manage for this pest. We saw cyclamen mite damage in older fields as well as first-year bearing fields, so check all fields before renovation for cyclamen mite damage (Figure 1.). Check out previous berry bulletins to find more pictures of cyclamen mite damage (June 8th). If you have damage the entire field or at least the entire variety should be sprayed.
- After renovation Vegol crop oil can be applied in a high water volume to ensure thorough coverage.
- Agri-mek is registered for Two-spotted spider mite (TSSM) post-harvest. If you are applying agri-mek for TSSM you will achieve some efficacy on cyclamen mite.
- Apply Agri-mek once there is new growth after mowing, which could be approximately 5 days after mowing. Apply Agri-mek at 225 mL/ha in 750-1000L water /ha, with a non-ionic surfactant at .1-.5%
- Slow down and get thorough coverage of the plants and crowns.
- Apply Agri-mek under slow-drying conditions to improve uptake into the leaves.
- Do not apply sinbar after applying Agri-mek. Wait 5-7 days after Agir-mek before applying sinbar.
- Avoid spreading cyclamen mites to new fields; work in new fields before moving to old, infested fields.
- Check new fields for signs of cyclamen mites. The earlier we identify hot spots the better we can manage mite outbreaks.
Figure 1. Cyclamen mite damage at harvest.
- We have also seen two-spotted spider mites in strawberries (day-neutrals and June bearing) and raspberries.
- TSSM will cause plants to appear dry and scorched, and can build up rapidly hot weather. Check the lower leaf surface of middle-aged leaves for mites.
Strawberry Aphids: We have found winged aphids in new and bearing fields. It is very important to control this stage to stop them from flying and spreading virus to new fields.
- If there are more than 15 aphids on 60 leaves apply an insecticide.
- Beleaf, and Sivanto Prime are good products for aphid control and are not hard on beneficial insects. Cygon, Lagon, Admire and Assail also work well for aphid control but are hard on bees; do not apply these when bees are active.
- Exirel is also registered for aphid control. Exirel will also provide control of SWD if you have late-fruiting varieties.
- An aphid spray is likely needed every 2-3 weeks.
- Bearing fields will need an insecticide after mowing and new growth has emerged.
Tarnished plant bugs (TPB): Continue to monitor day-neutrals for TPB. If more than 25% of clusters have TPB nymphs an insecticide is needed. Rimon and Beleaf are friendly to beneficial insects but work best when applied to small TPB nymphs.
Blueberries: Early blueberries are being harvested in southern Ontario, and they are turning colour in eastern and central Ontario. Growers will need to begin managing for spotted wing drosophila. See the spotted wing update below for more management steps. Malathion and Exirel will control SWD and Japanese beetle.
Raspberries: The first raspberries are being picked from the south-west to the east. Harvest raspberries every 1-2 days if possible to keep the fields clean and SWD populations low.
Weeds: The OMAFRA Guide to Weed Control Hort Crops (Publication 75B) is now available. Go to http://www.blurb.ca/b/8811220 to order the english print version, or go to English Pub 75B (http://www.omafra.gov.on.ca/english/crops/pub75/pub75toc.htm) to download a free pdf copy.
Raspberry Crop IPM: now available! Check out http://www.omafra.gov.on.ca/IPM/english/raspberries/index.html for information on raspberry integrated pest management, including main raspberry pests. This IPM tool includes information on identification, biology, scouting, and management of raspberry insect, disease and disorders.
Spotted Wing Drosophila (SWD):
- SWD numbers have increased slightly this week.
- Stay up to date with SWD catches by following the ONfruit blog for weekly updates: https://onfruit.ca/
- Michigan and New York are also catching low levels of SWD
- SWD could be building up in overripe strawberries and wild hosts (wild raspberries, honeysuckle, mulberries).
- Do not leave overripe strawberries in the field; SWD populations can build up in this leftover fruit.
- Renovate strawberries as soon as possible after harvest to protect late varieties, raspberries and blueberries. Renovate early strawberry varieties before others if you are still harvesting late varieties.
- Ripening fruit needs to be protected in areas where SWD has been caught.
- Plan to apply an insecticide on raspberries and blueberries before harvest begins, and maintain coverage every 5-7 days.
- Pick early, clean and often. If possible, do not spray late blueberry varieties until they are close to harvest. There are limited options for blueberry growers so if you can leave blocks unsprayed until necessary the more options you will have. Fruit is not susceptible to SWD until it is turning colour.
- Use all forms of management- weekly sprays, regular, thorough harvest (every 2 days or less) and immediate post-harvest cooling to less than 5°C (preferably cooler).
- Don’t spray in temperatures above 27C.
- SWD is more active in the evening and early mornings. Spray from 6-10 am or 6-10 pm if possible.
- Pyrethroid insecticides (MAKO) will not work well in hot weather and will cause an increase in mites. Save the use of this product for later – when weather cools off and mite pressure is low
- This link will take you to an infosheet with the 2018 SWD registrations: https://onfruit.ca/wp-content/uploads/2018/06/registration-for-swd-june-2018.pdf , or check out Ontario.ca/spottedwing, including two emergency use registrations (Mako & Malathion 85 E).
- It is important for growers to do their own on-farm monitoring to evaluate the SWD status on their farm and their spray program.