Cedar Apple Rust this Spring


Pear, hawthorn, Quence, etc.


I used to have a Golden delicious and a Winesap but never got a harvest off them due to the CAR. Also my soil is very shallow and not suitable for apples so I have given up on them. I cut the trees down. Currently I have a couple saplings and seedlings I will graft and give away. I have found stone fruit is much easier for me to grow.


I’m trying to get the CAR spray timing right this year. About how many days / weeks is this Gall from releasing spores?


The next warm day with a rain.


It’s not days but moisture. Give that one some thick humid weather, and it’ll go to jellytown. You can’t miss it when it happens.


The picture I posted earlier in this thread is actually a cedar pear rust. Similar but different.


Can’t you just cut it off and torch it? Or encase it in a plastic bag so that when it goes the spores are contained and then you can chem them en masse



You can cut off the galls. They don’t seem to become infectious once removed from the tree. But you can’t get them all


I pulled all of that I could find off. I need to cut out all the ceders I can. Unfortunately, There are a bunch of them nextdoor. I’m watching the galls and the weather this year so I have the timing right.


That’s the best way. When you see them go all jelly, it’s time to spray


I manage so many orchards, precise spraying isn’t possible, but none of my orchards get debilitating CAR. Here scab requires more spray on very wet early seasons. Put highest legal rate of myclobutanil in oil spray at tight cluster. Then include myclo with your cap (for scab) in your 2 or 3 post petal fall biweekly (14 DAY) sprays and I doubt CAR will ever amount to more than a few random spots, even on the worst years. You don’t even have to spray your junipers.


CAR is a probably bigger problem than Scab around here. It could be different temperature range humidity during the inoculation period? I was trying to fallow the Midwest pest management guide which suggest spraying fungicide / bactericide throughout the bloom period. I applied Captan as suggested which is apparently very toxic to bees and I knocked back a colony here. I don’t understand why they suggest spraying chemicals that are toxic to bees in full bloom? I see from your comments that you know better than to do this.


Actually, off the top of my head I’m unaware of Captan toxicity to bees- but I never spray it during bloom anyway- I leave the trees alone throughout bloom- all species. Captan is not very helpful against CAR in any case.

I don’t know if the incubation time for CAR is longer down there, but don’t assume it is just because your gurus for commercial fruit production call for a lot of sprays- Cornell calls for a lot more sprays than I need in small orchards as well- pressure is much higher in commercial orchards because of scale (size of orchard).

Unfortunately, the only way you can find out how little you can get away with is to risk infection to some degree- but myclo has pretty good knock out power for a rescue if needed. It also is locally systemic and doesn’t get washed off once it sets.


Captan toxic? I spray it on strawberries in bloom and haven’t seen a problem

Here at CAR Central, I find that infection depends on the weather. The galls will jelly up, then subside if dry weather comes, then jelly up again - multiple times.

I’m planning to switch from myclo to Indar for the bloom sprays on apples


They are pretty much the equivalent for early sprays but I believe Myclo is much cheaper, especially because it is available in smaller packaging. I use Indar in my second insecticide (post petal fall) spray so its legal to use on stone fruit. I only need it at that time for stone fruit for extremely early ripening varieties. Indar is much better against grown rot, of course.

I did find a good source that suggests captan has some toxicity to bees. https://ag.umass.edu/fruit/ne-small-fruit-management-guide/appendices-resource-material-listings-conversion-tables-0


Good to know that. I see they particularly mention mason bees.

Of course there are so many sprays you NEED to make during bloom - like strawberries for botrytis


Is it necessary to spray for CAR every year? I seem to remember reading that if you break the cycle of it moving from Cedar to Apple then the next year you won’t find CAR in apples. Or something along those lines.
I sprayed immunox on my Apple last year and had no CAR. I only had few apples that I lost to squirrels. This year I’m hoping for more apples so I’d rather not spray immunox if I don’t have to.


There is the risk of neighbors’ ornamentals harboring the CAR. I have some wild berry trees of some sort that number in the millions growing in a windbreak containing cedars that have been having a rust fest for years, just waiting for me to plant apples or pears :slight_smile: So in my case, the CAR is ready to infect each year.


If you are surrounded by host trees, both cedar and junipers and you have wet spring like I do, you will continue to get CAR. If you don’t want to spray chemical, planted disease resistant varieties may be the way to go.


If you ever had CAR you have the other host, so you’ll keep getting it

And immunox helps with apple scab, as well