Sclerotium rolfsii
What do you call a fungus that can infect hundreds of type of plant and live on constitutive topic in the soil for eld ? A nurseryman ’s nightmare !
In this case , the incubus is called southern blight or southern stem . An insidious fungus calledSclerotium rolfsii(also known asAthelia rolfsii ) induce this disease .
It can rapidly kill apple and crabapple trees , dark walnut tree , and roses among many others .
Look for a web of white mycelia on top of the soil and the lower stem or trunk. Photo courtesy of Florida Division of Plant Industry, Florida Department of Agriculture and Consumer Services, Bugwood.orgvia CC 3.0.
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The name “ Sclerotium ” is a giveaway to what enable this fungus to be such a successful pathogen . It raise modest resting social organization bid sclerotia that can both live on organic matter and infect industrial plant .
What You Will Learn
Symptoms on Apple and Crabapple Trees
Once you notice the infection on your apple or crabapple tree , it will be too late to save them .
Look for sudden wilting , the decease of stems , and yellowing leaves , which will remain on the tree diagram . These symptoms typically manifest in the heat energy of the summer . Your Sir Herbert Beerbohm Tree ’s bow may turn brown and die near the soil line .
A telltale signaling is the web of bloodless mycelia on top of the dirt and the lower stem or trunk . The mycelia will produce the sclerotium , which are rotund , icteric or pinkish round object 1/8 of an inch or less in diameter .
Look for a web of white mycelia on top of the soil and the lower stem or trunk. Photo courtesy of Florida Division of Plant Industry, Florida Department of Agriculture and Consumer Services, Bugwood.orgvia CC 3.0.
tree typically die presently after the symptom become visible , although they might outlive for a calendar month .
How to Prevent Southern Blight
Like most other black apple disease , avoiding the trouble is your good wager . And we do n’t mean ignoring it !
If you eff that southern blight has been alive in the area , do n’t plant a tree diagram there . Common harvest that can serve well as reservoirs of contagion includetomatoes , soybeans , peanuts , and clover .
Obsessing about hygienics can help prevent southern blight . Since the fungus boom on dead plant tissue , be sure and take out any constituent matter from the base of your tree diagram . Part of this scheme include not permit harvest residuum work up up there . And make certain and control weeds under your tree .
To the sound of our knowledge , there are presently no chemicals register that can control southern blight .
Your Tree Will Become More Resistant with Age
The only lustrous side is that as your tree diagram amaze older , it will be less susceptible . One- to three - year - honest-to-god orchard apple tree trees typically contract the most severe southern blight infections .
The reason for this is that the barque will get thicker as your tree receive old . The fungus will have more difficulty fall into place it to cause contagion .
Geography May Spare Your Tree
As the name suggests , southern blight typically infects plants in the southerly part of the US . Northern growers are ordinarily ( but not always ) spare this plant killer .
Southern blight on apples is a particular problem in the Piedmont region in the SE . ( The tenacious region stretching from New Jersey to Alabama ) And it has been reported in nurseries and commercial-grade grove in Texas .
Avoidance is Your Best Bet
Since southern blight is usually disastrous to apple andcrabapple tree diagram , do everything in your power to avoid transmission .
Don’tplant apple treesin sphere roll in the hay to harbor this fungus . And keep weed and crop residues by from your trees .
Are you still trying to distinguish the disease infecting your tree ? Tolearn more about apple tree diseases , train out these guide next :
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About
Helga George , PhD
