I had
reports sent to me about peach trees with yellow leaves on a single branch. You
might see this on other fruit trees such as apple as well. For those of you
lucky enough to have this condition on your fruit tree then this may be an indicator
of a borer problem that needs treatment now. Let us talk about what else to
look for to confirm it and what to do.
reports sent to me about peach trees with yellow leaves on a single branch. You
might see this on other fruit trees such as apple as well. For those of you
lucky enough to have this condition on your fruit tree then this may be an indicator
of a borer problem that needs treatment now. Let us talk about what else to
look for to confirm it and what to do.
 |
| Borer problem on the limb of a three year old peach tree. |
Notice I
said, “yellow leaves on a single branch”. This is important because borers
usually lay their eggs on a single branch, not all over the entire tree. The
only exception is if your fruit tree is newly planted or less than two or maybe
three years old. In this case, the borers may find the trunk of the tree
enticing for egg laying and kill the entire tree outright. Usually borer damage
is in full sun, on the south or west sides of the trunk.
said, “yellow leaves on a single branch”. This is important because borers
usually lay their eggs on a single branch, not all over the entire tree. The
only exception is if your fruit tree is newly planted or less than two or maybe
three years old. In this case, the borers may find the trunk of the tree
enticing for egg laying and kill the entire tree outright. Usually borer damage
is in full sun, on the south or west sides of the trunk.
 |
| Jelly-like sap oozing from the trunk or limb of a susceptible tree after a rain is a pretty good tell-tale indicator of borers. |
Look for
sun or borer damage to the limb with yellow leaves on its upper surface. Borers
seldom affect the shaded sides of branches or on the north or east sides.
sun or borer damage to the limb with yellow leaves on its upper surface. Borers
seldom affect the shaded sides of branches or on the north or east sides.
 |
| Borer damage to a newly planted tree can be lethal because the tree is so small. |
What to
do? Buy an insecticide that contains imidacloprid listed in the active
ingredients on the label. Follow the label directions for a “soil drench” applied around
the base of the tree where water is applied. You would do this now but I would treat the tree as a non-edible for the next 12 months even if the label permits its use on fruit trees.
do? Buy an insecticide that contains imidacloprid listed in the active
ingredients on the label. Follow the label directions for a “soil drench” applied around
the base of the tree where water is applied. You would do this now but I would treat the tree as a non-edible for the next 12 months even if the label permits its use on fruit trees.
I have
had some luck using a sharpened, sanitized knife without an applied insecticide.
The knife is typically 6 to 8 inches long with a good-sized blade for removing
the damaged bark. The damaged area is skinned away from the limb until fresh
wood, not damaged by the borer, is seen. The damaged area cut away by the knife
is only about ¼ inch deep. This cut area is not treated in any way but allowed
to heal on its own.
had some luck using a sharpened, sanitized knife without an applied insecticide.
The knife is typically 6 to 8 inches long with a good-sized blade for removing
the damaged bark. The damaged area is skinned away from the limb until fresh
wood, not damaged by the borer, is seen. The damaged area cut away by the knife
is only about ¼ inch deep. This cut area is not treated in any way but allowed
to heal on its own.
 |
| I have had some luck using a clean knife and eliminating borer neighborhoods. I have no research to back it up but it seems to work sometimes. |
Hi Robert, in this post you recommended Bayer Tree & Shrub Insect Control but that product doesn't indicate that it can be used on fruit or nut trees. There is another Bayer product >> Fruit, Citrus, & Vegetable Insect Control that contains a smaller amount of imidacloprid and can be used on fruit & nut trees. The Bayer Tree & Shrub Insect control contains more than 10 times the level of the imidacloprid that is in the Bayer Fruit, Citrus, & Vegetable Insect Control so I would be hesitant to use the Bayer Tree & Shrub Insect Control on fruit & nut trees.
You are right. If the label does not include fruit trees, then it should not be used on fruit trees. Some of the products that contain Imidacloprid contain smaller amounts than others. Always read and follow label directions and apply the amount recommended by the label.