Cedar-apple rust resistance observation.

[Apple Junkie]

I have 6 varieties of apples growing in pots, all side by side. It is very noticeable which varieties are susceptible to cedar-apple rust, and which ones are quite resistant to this disease. The difference is shocking, with Franklin, Florina, and Dolgo being quite resistant, and Winecrisp, Honeycrisp, and Wikson crab being quite susceptible.

Pictured below in order… Winecrisp, Honeycrisp, Wikson, Florina, Dolgo.

 

[sandbur]

Chestnut crab and Red Baron have been quite resistant for me. I have to agree with your observation on dolgo.

 

[CrazyEd]

I see CAR most on these.
Goldrush
Frostbite
Winecrisp
Honeygold
Black oxford


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[Native Hunter]

I much prefer trees that don't get CAR, but I have one variety that gets it much worse than shown in your pictures and always manages to make a lot of fruit. I just looked at that tree today, and it was really bad, but the apples looked nice. I've noticed that tree seems to replace a lot of the leaves it loses during the season, and that's how it does so well.

Someone on this forum once used the term "disease tolerant," rather than "disease resistant," and I like that term to describe a tree that still is able to make good fruit despite not being a resistant tree.

I hate fireblight worse than any apple disease, and I won't plant anything anymore that isn't highly resistant to it. But, my neighbor had a full sized tree that tolerated it very well and made lots of fruit. That tree is gone now - taken by the new road. I didn't try to save that one, but did save some of the more DR varieties.

 

[Apple Junkie]

I think that is a good point Native. Even thought it's clear CAR is present, I am not sure how much real damage is being done to the vigor of the infected trees. So far, all continue to throw off new branches and the main leaders continue grow nicely. I'd still plant more of the CAR affected varieties, but it's surprising how clean other varieties have had the same exposure.

 

[Ben.MN/WI]

I grew up next to an old abandoned orchard that had lots of old apple trees growing near red cedars. Most of the apple trees had tons of orange spots on the leaves and often generally didn't look that great. But they still kept growing and kicked out huge amounts of fruit that wildlife loved.

At my place I have dozens of different kinds of apple trees growing within yards of mature red cedars. I really like the cover that the cedars provide, so I can't bring myself to cut any down. Some of the trees show CAR damage on the leaves, but they still keep growing. It seems like they grow a little slower in general than the less affected trees, but they are still alive and some are starting to produce fruit and they are only 4 years old (not bad for primarily standard rootstock).

 

[Bowsnbucks]

I noticed the term " tolerant " on some sites in contrast to " resistant ". I e-mailed the head of PSU's fruit tree dept. and asked him what the difference was. Like Native said, the PSU prof told me " tolerant " means the fruit tree variety can get the named disease, but it won't adversely affect fruit production, or tree health necessarily.

 

[Native Hunter]

My trip to the farm today reminded me that CAR is the least of my problems - Japanese Beetles were running rampant.

 

[Maya]

Apple Junkie, for what it's worth, the HC's do not get it on the fruit, just the leaves.......nice pics!

 

[Apple Junkie]

Good to know Maya. I'm planting the Honeycrisp more for the wife, than for the deer, so be nice if they looked as good as they taste.