July 19 Berry Bulletin
Strawberries: Valley Sunset and other mid-late season varieties continue to be harvested, and the first Malwina are beginning to be harvested in southern Ontario, and there is still bloom present in eastern Ontario.
Renovation is beginning; Assess your fields before renovation for weed pressure to determine if herbicides are needed and if so which herbicides to use. Broadleaf herbicides need to be applied 5-7 days before mowing. Avoid applying herbicides if temperatures are above 25C. After renovation do not apply sinbar in close sequence to grass herbicides (10-14 days). Herbicides such as Sinbar and Devrinol as pre-emerge products require 1-2 cm rain or irrigation following application. Refer to the Publication 75B Guide to Weed Control Hort Crops for herbicide options.
The earlier you can apply the herbicide (if necessary) and mow your strawberries the better for SWD management- don’t wait for the late varieties to be done harvest. Mowing will help fruit dry up and be less attractive to SWD. Renovation is also a good time for cyclamen mite control. See below for more information on products and timing for mite management.
Spring-planted day-neutrals are beginning to bloom and overwintered day-neutrals harvest will begin again soon.
Insects: Monitor for tarnished plant bugs, strawberry aphids, thrips, slugs, cyclamen mites, and two-spotted spider mites. In new fields insecticides may be needed for potato leafhoppers and aphids. After harvest renovate and mow the plants as soon as possible to reduce SWD populations building up if there are other berry crops or later strawberry varieties on the farm.
Strawberry Aphids & Virus: If you have not applied an aphid spray in your new fields it is important to protect those fields now before winged aphids fly in. Bearing fields will need an insecticide after mowing and new growth has emerged.
Cyclamen mites: Before renovating check fields for any mite damage. Flag any areas with damage for management after renovation or next spring. Damage has become more evident in the last couple weeks and management after renovation will be needed at some farms. Renovation is a good time for cyclamen mite control if this is a pest on your farm. Check newly planted fields as well. Mites may be difficult to find where there isn’t much new, succulent growth, but the population will likely build up again in August or September.
If a miticide is needed after renovation:
- 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 Agri-mek before applying sinbar.
- Avoid spreading cyclamen mites to new fields; work in new fields before moving to old, infested fields.
There is limited Agri-mek available so if a spray is needed line up Agri-mek earlier than later. If there is damage the entire field or at least the entire variety should be sprayed.
Potato leafhoppers: In new strawberry plantings choose products that will control aphids and leafhoppers, such as Sivanto Prime, Assail, Admire, Cygon or Lagon.
Disease: Cases of anthracnose have been found in a few June-bearing fields. Fungicides are beginning to be applied to day-neutrals as bloom begins for anthracnose, powdery mildew and botrytis. Anthracnose resistance to group 11s (including Pristine, Cabrio and Quadris Top) has been identified in Ontario. Tank mix these products with a group M for resistance management.
Blueberries: Harvest began this week in southern Ontario, and is a week or more away in eastern Ontario.
Phomopsis Twig Blight has been found this season causing flagging of young twigs and collapse of blossom and fruit clusters. If you are seeing similar symptoms confirm a diagnosis by sending to a lab. Phomopsis twig blight can be managed by pruning out blighted tips now or during dormant pruning.
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 later. Fruit is not susceptible to SWD until it is turning colour.
Raspberries: harvest continues this week and volume is increasing. Raspberries are very attractive to SWD so it is important that you keep your fields as clean as possible and maintain a tight spray schedule if possible.
Spotted Wing Drosophila: SWD has been caught in Chatham- Kent, Essex, Elgin, Norfolk, Hamilton-Wentworth, Niagara, Wellington, Halton, Durham, Northumberland and Ottawa-Carleton county.
Pressure is beginning to increase and if there is ripe fruit present in your area it is at risk for SWD damage. SWD should be managed by harvesting early, thoroughly and often- every 1 to 2 days. Weekly sprays will help keep SWD under control, and in all parts of the province insecticides will likely be needed on late strawberry varieties and late summer-fruiting raspberries. Stay up-to-date on SWD trap catches by following our blog: onfruit.ca.
With rain in the forecast this weekend in some areas, check out this article from John Wise, Michigan State University Extension on Rainfast Characteristics of Insecticides on Fruit: https://www.canr.msu.edu/news/rainfast_characteristics_of_insecticides_on_fruit. This article includes information on how much rain will warrant a re-application. For products like Delegate and Malathion after 0.5 inches of rain there is insufficient coverage for SWD control, based on this article.
Do not count on sprays alone– use as many of these tools as possible through the season to control SWD:
- 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).
- SWD is more active in the early morning and evenings. Spray from 6-10 am or 6-10 pm is possible.
- Research has shown that Assail has some activity on SWD eggs and larvae, but not adults. Assail can be used now to control leafhoppers in day-neutrals.
- 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
- SWD registrations are posted on our blog here: https://onfruit.ca/2019/06/21/registrations-for-spotted-wing-drosophila-june-2019/
- Check our blog for regular SWD updates and counts