Scott,
My reading was that the spores are long gone before the leaves sprout out, but this was in California and not the east coast. So perhaps a persistent freeze merits different treatments?
Hmmm, someone should get to the bottom of this. No time for searching this morning for me. Got to go spray.
Here is a pretty good page describing it:
http://eol.org/pages/188590/details
According to this page the spores can survive on bark and bud scales so removing leaves is not likely to help. The real question is if spores can be created there, if not then picking off leaves before they make spores should eventually remove all spores. According to the article shoots and fruits are also susceptible and it could be that is where spores could be created not on leaves. But I have never noticed any shoot infections. Maybe I had small enough outbreaks that the shoots never got seriously infected.
“The disease cycle starts when the overwintering bud conidia/ blastospores/ yeast cells come in contact with the young leaves. These structures overwinter in the bark and bud scales of the tree and acts as the primary source of inoculums.”
“Removal of the diseased leaves won’t help much because the pathogen survives in bark and bud scales.”
Thats the remark I was paraphrasing above. What is not made clear is how there is going to be pathogen on the scales if you have cut off the lifecycle by not letting it sporulate. Either it is from surviving multiple winters or because of an infection on a twig.
Perhaps for mild infections there will be little in the way of twig infection so you can cut it off by removing all the leaves. But for more serious infections there will be enough from the twigs and removing leaves may not help appreciably.
“This fungus is believed to survive the winter by staying on the surface of the new host plant, such as on bark or buds.[4] In the spring, new buds are infected by the conidia as the leaves emerge from the buds. The disease does not occur every year, as it requires a minimum of 3mm of rainfall followed by at least 12 days during which the developing conidia remain damp and at temperatures below 19°C.[5][6] The fungus has higher infection rates following cooler, damper winters.”
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Yes I had read the same thing as well. Whats your point? The bit about the disease not occurring every year?
Condia can’t last forever so if there is no source of fresh condia the infection will eventually end.
Infected leaves develop a whitish bloom as the infection progresses. This bloom consists of asci that break through the cuticle of the leaf by way of lysis.[3] One ascus contains eight ascospores that create conidia, which are ejected in early summer and moved by rain and wind.
This indicates that the condia above that are starting the infection in the spring are created by asci on the leaves. If there are no infected leaves left there are no asci so there are no fresh condia so the disease dies out.
Sorry for going off topic but does peach leaf curl effect nectaplums like Spice Zee? I have one coming soon and wonder if I should hit it with copper?
Yes,mine has a bunch of the stuff,even after spraying about four times with Bonide’s Fung-onil from Fall to early Spring.So,I don’t recommend that brand.I’m going with Copper next year.Possibly a larger dosage will work with Fung-onil,but a person has to live with the results for a year if it doesn’t.
Speedster,I’d spray anything with a Peach or Nectarine in the makeup. Brady
Thanks. Should I just add the copper to my dormant oil?
Sure,but only spray if the plant is still dormant.The nursery might have already treated the tree. Brady
I spray my trees with copper hydroxide (Kocide 3000) 5 times per year and only two of those are during the dormant stages of the deciduous fruits.
Richard,
What diseases are being targeted? Brady
It’s a laundry list including several species of phytophthora, fireblight, fungi such as peach leaf curl, …
Copper is phytotoxic so make sure to read the label if you are doing any application on leaves. Unless you have certain diseases giving you big problems (fireblight and bacterial spot in particular) there is not much of a reason to use it in the growing season - its not effective against brown rot or other summer rots.
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Yes, I’ve discovered my Naranjilla is very sensitive to it.
The directions on the Kocide 3000 label are thorough. When I treat with copper I also chemigate with it for soil drench.
Due to the intense insect pressure – particularly on Citrus, I rotate through these insecticides using one per month and each twice per year:
Assail 30SG
Admire Pro
Evergreen EC
Baythroid XL
Conserve SC
Malathion SEC
You drench the soil with copper? Isn’t that toxic to earthworms? Are you sure there might not be other soil effects? It’s not like boron but is a lot of copper safe for soil flora and trees?
That’s a potent mix of insecticides. Do the labels recommend that rapid of a rotation? I rotate three miticides on a three year basis. That is use the same one for a year, 1-2 applications, and then the same for two others the next two yrs.
Copper can combat fireblight? My D’Anjou has a mess of fireblight… can I really use copper on it? I thought the only solution was to remove infected branches.
Copper might reduce infection but once it’s inside the plant it won’t help. It needs to be cut out.
Copper can combat fire blight efficiently. But copper is a toxic and can be built up in the soil so need use it under conscious