Apples Diseases Insects Pest Management

Apple Update: April 27, 2016

The OMAFRA Apple Team will be providing weekly crop updates reported from across the province, including growth stages, production, weather-related impacts, pest status and other issues affecting Ontario growers at the time. Continue following ONfruit for up-to-date crop information.

Growth Stages

Apple buds are at tight cluster in Essex County; half inch green to tight cluster along the rest of the north shore of Lake Erie in Chatham-Kent, Elgin and Norfolk County and in the Niagara Region; green tip to ¼” green in Grey and Northumberland County and Durham Region.


Pruning has been ongoing over the last two months; some growers are already finished. Tree planting began last week and will continue for the next two weeks or so.


Dormant copper has been applied in many orchards for fire blight to reduce overwintering bacteria that ooze out of cankers. Rains occurring after application may have partially washed off the copper, reducing the effect of this treatment.

Most areas have at least one scab protectant spray applied. Earlier regions of the province have experienced a few potential infection periods already this season. The cooler weather during the recent rains may have decreased the likelihood of a scab infection due to prolonged leaf wetness requirements. During breaks in prolonged wetting events, many growers are opting to re-apply fungicides to replace residues washed off. Others are choosing to apply a product with good post-infection activity when conditions dry.

High powdery mildew pressure last year followed by a mild winter has some growers concerned about management this season. A low rate of sulfur is being incorporated into a protectant scab program in orchards with a history of powdery mildew. Some orchards with historically low powdery mildew pressure are using dormant and summer oil sprays to help with suppression.


European red mite eggs are quite prevalent on fruit spurs in many orchards. With the warmer weather, growers have been applying dormant oil for scale and mites.

Traps for oriental fruit moth, apple leafcurling midge and European apple sawfly will be going up in many regions over the next week or so to monitor adult flight.


Herbicides are being applied over the next few weeks during the critical weed-free period.


2 comments on “Apple Update: April 27, 2016

  1. Terry Wright

    Kristy: I like the foremat and items. The EaSTERN mICH. REPORT LAST NITE REPORTED ACTIVITY WITH c.m.,o.f.m.,s.p.l. AND LEAF ROLLER [RED].ANY ACTIVITY REPORTED IN Essex cOUNTY BY SCOUTS. oUR SCOUT AROUND TODAY 1ST TIME . Still cold 3 this a.m. Terry

    • Kristy Grigg-McGuffin

      Hi Terry: Glad to hear you found the update worthwhile!

      Most areas are just putting up OFM traps this week, so we will have a better idea about flight in the next week or so. Generally, the Essex area is just shortly behind Michigan in terms of pest activity.

      Codling moth traps don’t usually go up until pink/bloom. Catch is rare at this time. There may be sporadic catches of adults that survived the mild winter, but likely not the start of the first generation for this season. At any rate, unlike OFM which can damage growing shoots early season, codling moth damages the fruit only.

      In Ontario, traps for leafminer and early season leafroller (exception OBLR) are not commonly used to monitor adult flight. Instead, visual assessments of presence of eggs and/or larval feeding on terminals and leaves are typically used for thresholds.

      All of that being said, the temperatures are still quite cold this week. I imagine this will slow any insect activity that may have started.

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