Anybody, I just bought a chinese chestnut what is on these leaves?
- Thread starter rhawes
- Start date
0soyoung
Imperial Masterpiece
I think it is a fungus. This also commonly happens to horse chestnuts.
Based on my experience with horse chestnut, you could defoliate and get new leaves, if you do it within the next week or two. After that it will set buds and just look at you until next spring --> there is a big switch with the passing of the summer equinox.
Spray with your favorite fungicide as the new leaves are emerging and they should last to near time for leaf drop without any ugly spots. Spraying the existing leaves won't accomplish anything because topical fungicides cannot get to the hyphae inside the leaf, so they are just a source of spores for continuing infection. Sprays just kill incoming spores on [lant surfaces.
Based on my experience with horse chestnut, you could defoliate and get new leaves, if you do it within the next week or two. After that it will set buds and just look at you until next spring --> there is a big switch with the passing of the summer equinox.
Spray with your favorite fungicide as the new leaves are emerging and they should last to near time for leaf drop without any ugly spots. Spraying the existing leaves won't accomplish anything because topical fungicides cannot get to the hyphae inside the leaf, so they are just a source of spores for continuing infection. Sprays just kill incoming spores on [lant surfaces.
NOZZLE HEAD
Shohin
Looks bacterial to me.
Those definite angular margins between infected lesions and the rest of the leaf are really indicative of bacterial diseases in general.
Those definite angular margins between infected lesions and the rest of the leaf are really indicative of bacterial diseases in general.
Chestnut (Castanea spp.)-Bacterial Blight
Cause Pseudomonas sp., a bacterium. There are few descriptions of this disease. It has been reported in Japan and found in Oregon. The bacterium...
pnwhandbooks.org
rhawes
Shohin
Thanks for the input I defoliated it and we will see I guess I will treat with physan 20 and see what happens after that thanks again all or if anyone has any other suggestions of what to use would be appreciated
I get this every year, this year I have tried for the first time to avoid it by spraying a systemic as the leaves appear before they have matured. So far much better than I have ever seen it at this time of year, I have seen a few spots that I have cut off right away and the tree is still looking very good. I was late applying it due to another issue but I am still very optimistic.
Horse-Chestnut Leaf Blotch (Guignardia aesculi) is what I have had.
Look here on page 25
I have also seen these recommended chlorothalonil or mancozeb, I used Propiconazole and so far so good but like Oso said these leaves are toast. Common to everything I have read is timing, as they mature, I don't think sulfur or copper will slow it down at all.
My fingers are crossed good luck with yours.
Horse-Chestnut Leaf Blotch (Guignardia aesculi) is what I have had.
Look here on page 25
I have also seen these recommended chlorothalonil or mancozeb, I used Propiconazole and so far so good but like Oso said these leaves are toast. Common to everything I have read is timing, as they mature, I don't think sulfur or copper will slow it down at all.
My fingers are crossed good luck with yours.
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