Black knot disease on purple plum

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Gardener fred
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Black knot disease on purple plum

Post by Gardener fred » Mon Jan 16, 2017 3:34 pm

What type of fungicide should I use when treating black knot disease on my purple plum?

lorijones
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Re: Black knot disease on purple plum

Post by lorijones » Mon Feb 13, 2017 11:44 am

It is important to first prune out any branches that contain knots. Prune at least 2" - 4" below the knot. This should be done now - during the dormant season. Be sure to burn or discard the pruned branches so the fungal spores cannot reinfect the tree.
Fungicides may be helpful as a preventative but only if the knots are first removed through pruning. Products containing chlorothalonil such as Bonide Fung-onil or a copper spray such as Bonide Copper Fungicide may help prevent the spread of the disease. Here is some more information on this fungal disease: http://inthegardenradio.com/v.php?pg=334. Good luck - it can be hard to control.

Gardener fred
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Re: Black knot disease on purple plum

Post by Gardener fred » Mon Feb 13, 2017 8:31 pm

Thank you for the information!

Jerryknott
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Re: Black knot disease on purple plum

Post by Jerryknott » Sat Feb 16, 2019 8:44 am

This problem could be due to the appearance of some insect on the flower. This plant may have infected with insects and are spreading the infection all over the roots and to the other flowers also. To get rid of these pest issues you can try out using some pesticide sprays or can also contact the pest exterminator UES for some help in this problem.

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