by Diane Sagers
CORRESPONDENT
In my mind, summer just is not complete until I have enjoyed a freshly picked peach right off the tree. It is instant gratification to pick that delicious morsel and bite into its sweet, juicy goodness. There is nothing quite as good as picking fruit from a backyard tree when it is at its peak and enjoying its sweet, fully developed flavor. A very close second best is to slice up freshly picked peaches and serve them with sugar and cream.
In order to have this treat as a homegrown delight, one must have a peach tree. That is not too difficult since peaches grow pretty well in Tooele County. Their chief growing problem is iron deficiencies caused by our alkaline soils. Nevertheless, they remain a good backyard tree fruit.
The unsettled springs here mean that the blossoms do freeze from time to time, but they produce fruit often enough to make the effort worthwhile.
Unlike cherries and apples -- which must be sprayed frequently to reduce or prevent insect damage -- peaches require very little insect care. However, there is one major stone fruit pest that home gardeners should prepare for even before they see it. Peach tree borers can cause serious damage or even death to peach, nectarine, apricot, and plum trees, as well as ornamental versions and other stone fruits.
The adult borers, Synanthedon exitiosa, are clearwing moths that emerge from pupae under the tree bark or in the soil in mid to late June. They mate and begin laying eggs during July and August. The adult female lays from 200 to 1,200 eggs on the bark of the lower trunk and in soil cracks near the base of the tree. These insects are particularly attracted to trees that have previously been damaged by borers or trees with mechanical injury or cracks in the trunks. They occasionally attack larger roots at or near the soil surface.
As the eggs hatch, pinkish-white larvae with brown heads emerge and tunnel into the sapwood of the tree through cracks and wounds in the bark. You are not likely to see the larva since they are .06 inch long when they first hatch and burrow into the tree. They continue to feed and develop until the onset of cold weather. Then they spend the winter as partially grown larvae under the bark and in the ground. The fall activity, occurring a few inches on the lower trunk below ground and on larger roots, isn't as harmful as what happens the following spring when they resume activity eating much more than before. The fully grown larva may be up to 1 1/4 inches long.
Sometime in late May, they stop eating and pupate for about a month in the chewed wood fragments and gum from the tree. Adult borers emerge and the cycle begins again.
The symptoms of peach tree borers usually appear in late winter around the base of the tree trunk as sawdust mixed with yellow brown blobs of a jelly-like substance that dot the base of the tree. The borers may cause extensive damage that can ruin a tree. If the tree oozes gum anywhere other than in the lower trunk or around the base, it is not due to peach tree borers.
Do not wait to see symptoms of an invasion before you treating the trees. Prevention is the name of the game and good timing of sprays is the best game plan. Since the borers burrow under the tree bark, sprays are aimed at controlling the small larvae before they burrow into it.
Treatment to prevent these pests should begin this week and continue through late August to early September. Even if you haven't seen these pests on your peaches or nectarines, take time to control this insect and maintain tree health.
Spray the first week of July on the lower parts of the trunks only and reapply the first week of August using products containing permethrin or esfenvale. Products such as Pounce or Ambush contain permethrin and Asana contains esfenvalerate. Thoroughly cover the lower 12 inches of trunk and soak the ground at the base of the tree. Do not allow the sprays to contact fruit. Remove debris or weeds at the base of trees to avoid interference with spray coverage.
Protection of host trees from peachtree borer is the most critical during the first three to five years after planting. Damage on small trees may kill them in one season. Older trees may withstand the damage, but it leaves them predisposed to further attacks and damage from other insects and diseases after several years.
Healthy trees without injury are less prone to attack, so keep your trees as healthy as possible and avoid mechanical damage to avoid borer infestations.
If you do get borers in your fruit trees, you can go after them individually as a last resort during the fall and winter months only. Remove the gum and rotted wood from the damaged area and insert a knife or wire into entry holes. Kill larvae in late summer and fall before they spend the winter and do their most severe damage the following spring.
Tips for the week
* Lawn water requirements -- about 2 inches per week
* Raise mower blades to 2 1/2 to 3 inches high for healthy turf growth.
* July 1 last chance to plant turnips, spinach, cabbage, peas, and chard, sweet corn, snap beans and lettuce for fall harvest.
* Plant seeds for Brussels sprouts, broccoli, Swiss chard and cauliflower for fall harvest.
* Treat corn silks to control corn worms.
* Dig, divide and replant iris.
* Fertilize lawn six weeks after last application.
* Remove spent flowers on perennials.
* Remove water sprouts from fruit trees.