Production and pest update brought to you by the OMAFA Apple Team: 

Erika DeBrouwer, Tree Fruit Specialist and Kristy Grigg-McGuffin, IPM Specialist

Grower Grind

The time of year we have all been working towards. Apple harvest is underway in most regions for early timed cultivars! Yay! Many regions are hoping for a little bit of rain given the past few weeks of dry weather. Cool nights seem to be in the forecast, so we are hoping the weather forecast stays true. We are wishing you all the best over the harvest season!

Growth Stages

Regions in southern Ontario are harvesting early cultivars like Sunrise, Zestar!, Gingergold and Paulared, where some are on their second pick. Other apple cultivars and regions continue to size with colour developing the closer we get to harvest timing. Generally, growers are stating good size with lower yields in comparison to normal.

Concerns on Colour

Early regions are noting warm nights (with cool nights forecasted), and therefore are thinking about colour improvement strategies. Check out the resource below covering the following:

• Reflective ground cover (A quick reference guide found here)
• Leaf removal
• Plant growth regulators
• Nutrients

Rouge Regime

Regarding reflective ground cover, a study out of New York State showed that reflective covers vary in efficacy based on material and placement “with the highest percentage of reflection from Extenday 90%, followed by Mylar in the herbicide strip and Extenday 80% and, finally, Mylar between the tree rows.”

Harvest Homework

For those wanting more information on testing apple maturity check out the resources below:

• What the Crop?! Apple Update: August 22, 2025 – ONfruit
• ONcore Newsletter Vol.28 Summer 2024
• Orchard Network Newsletter Vol.26 August Issue 2022

A Core-dinated Record

Be sure to keep track of harvest details for future reference. Looking back to help determine the do’s and don’ts will pay off in the long-term. Remember to include:

• calendar date of harvest
• yield and other quality parameters (size, firmness, colour, weight)
• length of time stored/when apples were removed from storage (if you have access to this)
• pay out for crop
• it would be good to write down GDD and night-time temperatures for reference for the week(s) prior to harvest

Remember that record keeping and harvest maturity assessment strategies should be used in collaboration with one another to give you a better idea of when to harvest.

The PHI Files – Revisited

As harvest approaches, preharvest intervals (PHIs) need to be part of every spray decision, especially in early cultivars where the harvest window can close quickly. Before making a late-season application, double check the label and any information from your packer for the PHI, maximum number of applications or seasonal use rate, and any market/export restrictions.

For more on late-season pest considerations, check out What the Crop?! Apple Update: August 7, 2026.

All PHI are listed on the product label and can be found under ‘View Details’ for each product on the Ontario Crop Protection Hub.

What the Crop?! Apple Update: August 7, 2026

Black Rot & Ready to Hang

Black rot continues to be noted across the province, particularly in blocks and cultivars that tend to hold fruit. These fruit mummies are likely from last season’s thinning that held on over the winter and harboured the pathogen.

Infection will continue on susceptible fruit under warm, wet conditions, while symptoms may become more apparent as fruit matures. Black rot does need an entry point for infection, which is often why it can be found around lenticels/pores and the calyx.

At this point, management should focus on protecting marketable fruit that is still some distance from harvest, while factoring in disease pressure, weather (rain is in the forecast!), and PHI. Make a mental note to return to problem blocks during dormant pruning to clean out any dead or cankered wood – and maybe even fruit mummies if labour allows – to reduce inoculum for next season.

For more information on registered products or those with efficacy against black rot, see Black rot on Ontario Crop Protection Hub.

The table below summarizes activity of fungicides that could be used for summer disease control. Residual protection will vary depending on the product used. For example, Pristine can provide reasonable residual control of summer disease up to 3 weeks at the labelled rate in ideal conditions; however, captan should not be pushed further than 14-days between sprays particularly since it is not as strong on fly speck and sooty blotch as other control products. In all cases, reduce interval to 7 days during times of hot, wet weather.

Activity of registered fungicides on fly speck/sooty blotch, black rot and bitter rot

Product	Group	PHI	Scab	Fly speck / sooty blotch	Black rot	Bitter rot
captan	M	19 days*	+++(+)	++(+)	+++(+)	+++(+)
folpet	M	1 day	+++	++	++(+)	+++NR
Senator	1	1 day	+++	++++NR	+++NR	+NR
Aprovia Top	3+7	30 days	++++	+++	—	—
Inspire Super	3+9	14 days	++++	+++(+)	—	—
Cevya	3	0 days	+++(+)	+++	++	—
Pristine	7+11	5 days	+++(+)	+++(+)	+++(+)	+++(+)
Merivon	7+11	0 days	+++(+)	+++(+)	+++(+)	+++(+)
Flint	11	14 days	++++	++++	+++NR	++(+)NR
Diplomat	19	0 days	++NR	++(+)	++NR	++
Allegro	29	28 days	++(+)	+++	+(+)	+++
Downforce	29	28 days	++(+)	+++	+(+)	+++
Vantana	29	28 days	++(+)	+++	+(+)	+++NR
Regalia	P5	0 days	+(+)NR	+(+)	++NR	+(+)
LifeGard	P6	0 days	++	++	—	—
Phostrol	P7	1 day	—	++	—	—
OxiDate	NC	0 days	+(+)	+(+)	+(+)	—

Have You Any Wool?

Woolly apple aphid has been slow to develop this season but colonies are becoming more noticeable now with populations building on pruning cuts, branch crotches, water sprouts and suckers. Late in the season, crawlers and winged forms can continue moving within and between trees, extending activity well into the fall. Beyond the obvious nuisance factor (staining, irrigating skin, etc), honeydew can contaminate fruit and encourage sooty mould, while feeding damage can weaken shoots and make limbs more susceptible to winter injury.

If control is needed before harvest, quick knockdown is priority – but options are limited by PHI, product activity, and the fact that the waxy coating over these pests helps protect the colony from contact sprays. Thorough coverage will be essential, particularly in dense canopies this time of year.

For more information on registered products or those with efficacy against woolly apple aphid, see Woolly apple aphid on Ontario Crop Protection Hub.

Small But Mite-y

European red mite and two-spotted spider mite are also flaring up in some orchards. Late-season mite feeding can cause bronzing and reduced photosynthetic capacity at a time when trees are still building and storing carbohydrates for dormancy. Heavy pressure can affect fruit finish and reduce winter hardiness, so high pressure is worth addressing – even this close to harvest.

Before spray, check what life stages are actually present. Products can differ in activity: some are slower and better suited to eggs or developing populations, while others provide more rapid activity against motile stages. Prioritize something this time of year with quick knockdown that fits both the dominant lifestage and PHI.

The table below describes the activity of commonly registered miticides for European red mite and two-spotted spider mite.

For more information on registered products or those with efficacy against European red mite and two-spotted spider mite, see Mites on Ontario Crop Protection Hub.

Activity of Miticides Registered for European Red Mite and Two-Spotted Spider Mite

Product	Target Species	Life Stage(s) Affected	Preferred Timing	Knockdown
Acramite	European red mite Two-spotted spider mite	nymph, adult	postbloom	rapid
Agri-Mek	European red mite Two-spotted spider mite	nymph	within 21 days of petal fall	rapid
Envidor	European red mite Two-spotted spider mite	egg, nymph, adult (female)	postbloom	slow
Kanemite	European red mite Two-spotted spider mite	all life stages	postbloom	rapid
Kopa	European red mite Two-spotted spider mite	nymph, adult	as populations build, before damage observed	intermediate
Magister	European red mite Two-spotted spider mite	all life stages	summer	rapid
Minecto Pro	European red mite Two-spotted spider mite	nymph	within 6 weeks of petal fall	rapid
Nealta	European red mite Two-spotted spider mite	all life stages	as populations build, before damage observed	intermediate*
Nexter	European red mite Two-spotted spider mite	nymph, adult (ERM only)	summer	rapid
Purespray Green Spray Oil	European red mite	overwintering egg, some nymph	half-inch green to tight cluster prior to hatch	smothers eggs
Suffoil-X	Two-spotted spider mite	overwintering egg, some nymph	half-inch green to tight cluster prior to hatch	smothers eggs
Superior Oil	European red mite	overwintering egg, some nymph	half-inch green to tight cluster prior to hatch	smothers eggs
Vegol Crop Oil	European red mite	overwintering egg, some nymph	half-inch green to tight cluster prior to hatch	smothers eggs

Spot the Difference

Seeing unusual spots or blotches? A reminder that we have an on-going provincial survey, looking at what pathogens may be contributing to some of the leaf blotch symptoms around. For more information, check out Give Us Your Disease! Diseased Apple Leaves, That Is or contact Kristy at kristy.grigg-mcguffin@ontario.ca or 519-420-9422.

Give Us Your Disease! Diseased Apple Leaves, That Is