Unknown plum tree discharge - Ask Extension
I have found several blobs of clear amber colored discharge on various limbs of my young plum tree. Tree is beginning it's third year, and I applied ...
Knowledgebase
Unknown plum tree discharge #871124
Asked June 02, 2024, 10:54 AM EDT
I have found several blobs of clear amber colored discharge on various limbs of my young plum tree. Tree is beginning it's third year, and I applied copper spray this spring. Fruit and leaves look normal except for growth at the discharge point. Blob is hard to the touch, but has a slightly sticky surface. Is this normal or something I need to take care of? If so, what is your recommended remedy? Pictures attached.
Polk County Oregon
Expert Response
Oh no! This isn't looking good!
I'm seeing signs of a disease called bacterial canker. You can read more about it in OSU's PNW Pest Management Handbook. The globs of sap are one sign. Look closely. You'll also see dieback of the twigs and flowers plus some signs of cracking in the bark.
How long ago did you plant this tree? If it was this spring you may want to contact the nursery to see about a possible replacement.
I'm seeing signs of a disease called bacterial canker. You can read more about it in OSU's PNW Pest Management Handbook. The globs of sap are one sign. Look closely. You'll also see dieback of the twigs and flowers plus some signs of cracking in the bark.
How long ago did you plant this tree? If it was this spring you may want to contact the nursery to see about a possible replacement.
Wow! Not what I expected. Is the canker mostly transmitted through the ground and roots system, or through the air? The handbook doesn't paint a glowing picture of recovery, so is it better to spray and wait or remove? Will the canker spread to other non-plum trees? The trees are in their third year, grafted on a plum rootstock.. Hate to get rid of the tree, but may have to look for a different graft.
The bacteria that causes this issue typically spreads in splashing rain, irrigation water, or even on tools (could be spread by pruning shears, for example).
What types of trees do you have nearby? Are they also Prunus sp (cherry, peach, etc.)
What types of trees do you have nearby? Are they also Prunus sp (cherry, peach, etc.)
Yes - I have a peach nearby and different plum in the vicinity.
I'll add that my older trees do not show this symptom - just the new ones I planted.
Yes - I have a peach nearby and different plum in the vicinity.
If you decide to leave them in, then be very careful when moving between the trees. You don't want to inadvertently spread the bacteria to the unaffected trees. Any time you are creating a wound is especially vulnerable. So pruning, thinning and picking.
Work the unaffected trees first and then move to the diseased ones. Consider having two sets of pruners or giving yourself time to sanitize equipment between trees. Here's a short article comparing the different sanitizing solutions used.
Work the unaffected trees first and then move to the diseased ones. Consider having two sets of pruners or giving yourself time to sanitize equipment between trees. Here's a short article comparing the different sanitizing solutions used.
Thanks for all the help and info.
Dean
I have one more issue that has cropped up. I have a new peach tree (first year) that is showing spots on its leaves. New growth is vibrant green, and then slowly develops these spots, and then ultimately the leaves turn red. What is this (fungus, mineral deficiency, etc.), and what can I do to fix it?
Thanks again.
Dean
Thanks for all the help and info.Dean
Hi again,
Were the peaches sprayed with anything this winter or spring?
At least some of this looks like the start of shothole disease. This is a fungal disease that affects the leaves. The affected parts of the leaves fall out, leaving a shothole appearance-hence the name. Here's info on managing peach problems.
Looks like you might be losing leaves prematurely? Over time that will affect the vigor of the tree. Consider making treatments this fall and winter to help the tree next growing season.
Were the peaches sprayed with anything this winter or spring?
At least some of this looks like the start of shothole disease. This is a fungal disease that affects the leaves. The affected parts of the leaves fall out, leaving a shothole appearance-hence the name. Here's info on managing peach problems.
Looks like you might be losing leaves prematurely? Over time that will affect the vigor of the tree. Consider making treatments this fall and winter to help the tree next growing season.
Sprayed with a general fungicide. Thanks for the assist on this - I'll start a spraying program this fall.
Dean
