Plant Diseases/Red Apple Dying - over 30-years old
Darren wrote at 2016-02-08 01:36:15
I live about 90 miles south of Sharon, in San Diego county, and can confirm everything she says. It's not a moist soil thing, nor is it a low overnight temperature thing. And I don't see any signs of fungus on the leaves. Mine started last September-October, when we were having unseasonably hot weather. I have noticed it in just about every neighborhood I've driven through lately, so it must be some sort of air born disease. I took a sample to the dept. of agriculture at the beginning of December, and with typical government efficiency, the sample died before they got around to examining it (2 1/2 weeks later). Likewise, the local nurseries are stumped.
I'd sure like to hear from anyone who knows what this is and how to treat it. I spent almost $40,000 last year clearing and re-planting my slopes after a wildfire, and I don't really want to shell out that kind of cash again if I can help it.
Eva wrote at 2016-02-26 23:12:13
I have been reading articles recently (Feb 2016) that a recently arrived downy mildew from Africa has been implicated in the sudden dieoff of large amounts of red apple in southern California. The mildew thrives here apparently only on red apple (so far). Identification of the problem is recent and not much is known other than the mildew supposedly likes wet conditions. I have not yet heard of any cure for or heard of it going away even with various suggests like minimizing watering (which I already do anyway due to the drought). I can only hope that immune strains of red apple apple are found! Mine is looking really bad lately, might have to switch to a diff type of ice plant at this rate. Like you, we've had this red apple for many many years with never a problem so the sudden dieback for no apparent reason was a surprise.