Q. Can you help me identify what is causing Mesquite trees to
stress? I have attached photos here on this email. There’s sap releasing from
previous cuttings, but there has been more die back from the top (side of the
south) at a faster rate, any clue what is happening?
stress? I have attached photos here on this email. There’s sap releasing from
previous cuttings, but there has been more die back from the top (side of the
south) at a faster rate, any clue what is happening?
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| Mesquite tree dieback mentioned in the question. See how helpful good pics can be? |
A. Thanks for the detailed pictures. That
helps. The second picture you sent clearly shows where the mesquite tree was
pruned (actually it was a very bad pruning job called “topping”). The tree grew
vigorously from these cuts and then this new growth died.
Nothing Common
Nothing I could find has been observed in
mesquite like this in the past. We are going to have to start making some
educated guesses. Because it is in the new growth and seems to be very closely
associated with growth from previous pruning cuts, I would guess it is what we
call “a vascular disease” that plugs up the water carrying vessels from the
roots that travel up the trunk and through the limbs.
mesquite like this in the past. We are going to have to start making some
educated guesses. Because it is in the new growth and seems to be very closely
associated with growth from previous pruning cuts, I would guess it is what we
call “a vascular disease” that plugs up the water carrying vessels from the
roots that travel up the trunk and through the limbs.
Maybe Unsanitized Pruning Tools
My second guess is that
it MIGHT have been carried to this tree through the pruning tools. This could
be particularly true if the pruning tools were not sanitized before pruning. The most common reasons trees are pruned
is to remove dead or dying limbs. If these limbs were infected with a disease,
it is possible to take them from an infected tree and pass them off to an
uninfected tree. Development of the disease takes time. But if it was an
aggressive disease this could happen in a season. If not terribly aggressive,
two or more seasons.
it MIGHT have been carried to this tree through the pruning tools. This could
be particularly true if the pruning tools were not sanitized before pruning. The most common reasons trees are pruned
is to remove dead or dying limbs. If these limbs were infected with a disease,
it is possible to take them from an infected tree and pass them off to an
uninfected tree. Development of the disease takes time. But if it was an
aggressive disease this could happen in a season. If not terribly aggressive,
two or more seasons.
This kind of problem sometimes causes sap
“bubbles” to form on limbs. I call it “stress related”.
“bubbles” to form on limbs. I call it “stress related”.
What to do?
Cut the infected plant parts
out of the tree using a sanitized chainsaw. Remove at least 12 inches of wood
below where the infection started. Disinfect after every cut so that it is not
spread to other locations.
out of the tree using a sanitized chainsaw. Remove at least 12 inches of wood
below where the infection started. Disinfect after every cut so that it is not
spread to other locations.
Another possibility is borer damage. Less
likely but possible. If this is the case, do the same and disinfect just in
case.
likely but possible. If this is the case, do the same and disinfect just in
case.