spaying for plant fungus
I have a flowering crab apple that has shed it leaves all summer and currently looks as if its winter without its leaves. The leaves when on the tree showed first a spot as if touched by a hot cigarette, then a gradual turning of color from green to yellow then falling off the tree. The tree has also developed dead branches.
Is there a ground treatment available to treat the tree and possibly a spray that can be sprayed from a garden hose and water spray. The tree stands about 25 feet high. The infection started last year during very moist spring, followed by the hot summer. The spots appeared late summer and leaves started to turn color and then shedding. The tree sits between sidewalk and city street.
Venango County Pennsylvania
Based on your description of “cigarette burn marks” my guess is that your crab apple is suffering from cedar-apple rust disease. Very wet springs contribute to the problem along with proximity to host plants. I’m including links to web sites that describe the fungus, it’s causes, and treatments. https://extension.psu.edu/apple-diseases-rust The other possibility is apple scab so I’m also including a link for that fungus. https://www.canr.msu.edu/news/why_is_my_crabapple_tree_losing_leaves