So after hours of reading old posts on here I felt as though I knew what apple trees I was going to order, but after reading about cedar apple rust I’m concerned about a few of my choices as my acerage has hundreds of cedar trees. I’ve searched the web and have found conflicting reports on CAR susceptibility. Please let me know if my list seems right. Also, if I were to still order susceptable trees could CAR be prevented with a couple sprays Immunox or something similar? Heres what I’ve found:
Golden russet: CAR susceptible
Roxbury russet (to replace my plans of having a golden) very resistant on one site and susceptable on another.
Rubinette: no information
Zestar: somewhat susceptable and very resistant on another site.
Wickson: very susceptible
Chestnut: very resistant
Suncrisp: very resistant
Honeycrisp: somewhat resistant
Sweet sixteen: some resistance
After considering the issues I may run into at my place I’m thinking wickson and golden russet although at the top of my list should be removed, hoping roxbury would be a suitable alternative to golden. I still think honeycrisp should stay as it’s currently my favorite apple and I have not seen anyone mention disease on it. Thanks for any suggestions.
My wicksons, RRs and Rubinette have had little to no issue with CAR. One of my GR has been heavily defoliated by CAR and the one right next to it has had moderate damage but still fairly vigorous. The badly hit one is on b118 the moderate damage is on mm111. I don’t know if there is causation there. I don’t spray anything and I’m surrounded by cedars.
These trees have only been in the ground three summers so take this fwiw
Wickson is HORRIBLE, it was in my top three worst CAR varieties.
CAR can be prevented with one well-timed Immunox spray after bloom. After 10 years of being 100% organic one of the reasons why I switched to using some synthetic disease control was to get CAR under control.
I have wondered if there are different “strains” of CAR? Reports of varietal susceptibility or resistance are so variable from site to site, it seems quite confusing.
I was really hoping that Rubinette would not be on the list of susceptable apples as this sounds like one of the best flavor wise. I might still order one from the list of CAR prone apples just not all of them… either a wickson, G russet or rubinette and try my luck with spraying right after petal fall. The only other apple trees near my location have zero cedar trees within a couple miles so of course it’s never been an issue for them, but for me I’m thinking it would be.
I am starting to think that tree health and nutrition plays a larger role than realized. A lot of nitrogen promotes tender young growth that can be attacked but silica promotes thicker cuticles that resist attack. I have just scratched the surface on holistic orcharding (as in just looked into it this morning) while researching CAR resistant apples. I don’t know of any research into different strains of CAR but it makes sense that there would be variable populations with variable virulence. Chestnuts have a fungal blight that researchers have isolated different strains of with variable virulence. It is also worth noting that there are more than one species of rust in the CAR genus (see https://www.extension.purdue.edu/extmedia/BP/BP-132-W.pdf). Last year, one of my Asian pear trees also got what I thought was CAR but may have been cedar quince rust.
My house is in a subdivision that was built on land that used to be a christmas tree farm over 30 years ago. Because of this, the streets are all named after evergreen tree species and everyone in the area plants evergreens in addition to the ubiquitous flowering crab apples. So when I decided that I was going to plant random apple trees from the local big box stores without researching anything shortly after moving in, I was in for a crash course in apple tree diseases. I have a Fuji apple that gets defoliated completely every summer by scab and CAR. I used a copper spray last year and managed to get one single scabby apple. That tree will be completely top work next year, which is why I am researching CAR right now.
Like you, I am finding conflicting charts and recommendations. I have planted gala, granny smith, honeycrisp, pristine, and one of the newer starkbros trademarked gala/honeycrisp crosses because I read somewhere that they are resistant. Now i’m finding other websites that say that some of those are not resistant, or have personally experienced some of them getting CAR. That is why I am switching gears and planning to do multigrafts on each apple tree to test for CAR resistance as well as researching holistic orcharding to promote the tree’s “immune system.”
@Zafak
Your absolutely right but don’t forget genetics in the equation. Many of the best tasting fruits and vegetables are highly susceptible to insects and disease because of their genetic makeup. Hybrid and gmo corn can’t uptake cobalt among other minerals but that mineral prevents bruselosis in cattle , bison etc. . Open pollinated corn can uptake cobalt. The research has never been done on apples. I can tell you the few pear trees in my area did not all have a crop this year though my pears I grafted to wild callery pears did have a crop during a drought so bad there has not been one like it since the dust bowl aka dirty thirties. What advantage did my pears have we might ask? What did those wild genetics add to my trees that others lacked? What are the negative consequences of growing wild rootstock? I have more questions than answers at this time.
A very anecdotal observation along these lines: we have about twenty-five apple trees that we bench-grafted in 2016. Different varieties, mostly heirlooms. Last spring, I transplanted about twenty of those trees to form a Belgian fence. The rest I didn’t have time to move before they broke dormancy. The trees that I transplanted were far more affected by CAR than those that stayed where they were, and the trees that were transplanted relatively late tended to be more affected than the ones I transplanted relatively early. Now there could certainly be other factors involved, but I tend to think that the degree to which the trees were established (or not) may well have played a role.
All the trees were on G41, and I didn’t spray anything, though I would consider doing so in the future if need be. (Lots of untreated apple trees around here that seem to be pretty healthy.)
Thanks that site explained it pretty well for me. I will leave at least one of the susceptable trees on my ordering list and spray immunox a couple times in the spring, sounds like that can prevent it pretty well…
I’m very glad you made this thread since I, too, need to find some CAR resistant trees. I have quite a few cedars around me as well, and the biggest one was absolutely covered with those galls, so I know the CARS cycle is in progress here.
Is Roxbury Russet similar to Golden Russet? I thought I read that somewhere on a older post but could not find it back. Looks like it is highly resistant to CAR and at least has the same long keeping qualities as Golden Russet that I’m interested in.
I switched last year to Liberty trees. Very resistant to most everything (except deer). I’m just tired of fighting scab and cedar rust (really bad here). So, as my trees get weak, I cut them out and replace. I do have one tree I planted with the Winesaps (all doing poorly) that seems to be doing well. I forgot what the variety was, but it looks like a Jonathon. I’ll post a pic later.
Our trees are very young (second or third year from grafting to rootstock), but what I have observed so far is that root health/establishment seems to be an important factor in CAR susceptibility.
For example, I transplanted about twenty trees last year out of my little nursery area and into position to form a Belgian fence. Due to time constraints, a number of these trees were transplanted later than would have been ideal. Result: quite a lot of CAR! Meanwhile, a handful of trees that I did not have time to move were comparatively clean, in spite of being in a position that actually receives less morning sun.
This spring, after a year of getting established, the trees in the Belgian fence have been showing significantly less evidence of CAR. And we’ve had a pretty wet spring in New England, so I don’t think it’s a matter of the conditions being a whole lot better. (Though of course our conditions are not as challenging as those in some other parts of the country.)
There are Eastern Red Cedar everywhere here and as a result there are plenty of hosts to propagate CAR. I may try inoculating trees at planting to see if that helps. CAR is not the only fungus I have issues with as I have a vineyard as well, and this year has been idea for the fungus team!
I think I have the worst case of Cedar Apple Rust in over a decade. The only mortality (deaths) I’ve seen are to seedlings.
I have a Grimes Golden with a bad case, but I expect it to live just fine. And Anoka has it bad.
I have a great tree I’ve yet to positively identify, no CAR this year or any other that I recall.
Fuji has little too, same with Wolf River. Granny Smith has so many problems, this may be the year I cut the tree down…I could use the space for varieties I am anxious to get out of containers and into the ground. (And with G890, G202, G30…shouldn’t be any ‘replant’ issues).
(I don’t know if Bud-118 has any replant issues…anybody know?)
Anyhow, I’ve not known CAR to actually kill any trees…but it sure can defoliate them early. Grimes may be one of the worst.
If you have it re-occur yearly, it will weaken the trees to the point where it’s just best to cut them out and replace them with a more resistant variety (ie, Liberty). I have a Granny Smith and Golden Delicious that I have to cut out and replace.