Cedar Apple Rust on Fresh Bench Grafts

I’ll be doing the majority of my bench grafting this weekend and planting them in the nursery bed in about two weeks (May 8th). Some of the varieties are susceptible to CAR. Should I worry about it spraying the first year after grafting (ths year)? CAR is a problem here. I know Scott recommends myclobutanil. What do you all think of compost tea?

It depends on how high the CAR pressure is. In my location in central Illinois the disease pressure is light and the damage is mainly cosmetic so no spraying for it is a reasonable choice. In the South, CAR can defoliate trees and spraying susceptible cultivars is a must. I don’t know how high the pressure in your area is.

You have a ton of grafted trees right? Why take the chance especially since each graft will only have a small number of leaves. Plus with all of your grafts you certainly have cultivars that are susceptible to scab and other diseases so I think a modest spray program is a good idea.

Immunox (myclobutanil) is your best choice for CAR. There really isn’t a good organic equivalent for CAR. I don’t think compost tea will have any effect at all. I never have seen a study or field trial that shows it to be actually effective. You see a lot of claims that compost tea and neem oil are cure alls but you don’t see hard data that actually backs this up.

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If you’re going to grow CAR susceptible varieties in an area with high CAR pressure you may as well get used to spraying myclo.

As far as whether you need to spray your grafts this year, only your experience will show any such necessity. I get CAR here, but not a lot. I don’t spray my first year grafts. Oftentimes, by the time I plant my grafts in the field we are past the CAR window.

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What time do you plant them in the field? When is the window? When do you do your grafts then?

I usually plant out my new grafts in late May/early June. Some don’t get set out until later if they take longer to show new growth. I’ve had grafts pop as late as mid July. The CAR window varies from year to year. It all depends on spring temps and rainfall. I will graft in the next couple weeks. The grafts stay inside my unheated shed until they’re ready to be planted out. If I get some that take much longer to show growth, I’ll leave them in big tubs of dirt on the north side of the shed once all threat of frost has past…usually Memorial Day.

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Unless I change my mind, I’m not spraying for CAR since I haven’t in 30 years.

But, a cedar tree (juniperus Virginiana) fell on one of my apple trees and damaged it in the ice storm this spring.
So, maybe this is the year I should spray.
I’ve been grafting 100 or more trees for 4 years now and none have died from Cedar apple rust.

I think my worst case of CAR was several years ago on a Grimes Golden…that and scab.

Actually, serviceberries seem to get more damage than apples from rust.

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Do you think that’s because it is less of a problem for new bench grafts or because you just don’t have very high pressure in your area?

We have a lot of red cedars in the area and I have seen rust on a pear about 40 feet from my nursery bed.

Hawthorns here get rust badly. Some are defoliated almost completely by August.

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Several consecutive seasons of bad infections on highly susceptible cultivars can lead to tree death.

But, my worst infection happens to an “Anoka” apple on standard rootstock. It is about 16 feet tall and 30 years old. And currently probably has more than 1,000 apples set and petals are fallen.

It’s not for the lack of having cedar trees…I have a some I’m planning to cut for fence posts, and neighbors have plenty. I had planned to already have cut all mine…but haven’t gotten to it.

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For an organic approach, Michael Phillips “holistic” system does appear to prevent or at least limit CAR. Two years ago the only trees I had with serious cases of it were the ones at the end of a row, after I ran out of spray.

Southeast US so things may be entirely different here versus where you are. I bench graft, immediately pot, keep within waterhose reach the entire spring/summer. On M111 they’ll be roughly 6’ tall by the end of the season. That fall I transport 'em to the orchard area and plant them out. The soil will settle over the dormant period and the next spring they’ll be ready to really take off.

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I recall neem, seaweed extract/fish emulsion, and microbes as an early spray. Where do you get your microbes? I’ll be ready to spray as soon as this weather passes and the last blooms fall.

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Usually just from whomever has the best price on Amazon. EM-1 “inoculant” or however it’s typically worded. Smallest qty I can get then “grow” some more with blackstrap molasses for use throughout the rest of the season…

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