Spray with Dormant Oil in late February before the buds swell. Repeat every week from mid-August to late September. Spinosad may also be sprayed on the tree trunks as larvae hatch and sprayed directly into the borer holes. Spray three times at two-week intervals if infestation is heavy.
Spray trunks with Permethrin when larvae are hatching in April and May and again in mid-August to September to prevent the larvae from boring into the bark. Probe small holes in the trunk near the soil line with a thin wire to crush the larvae. If much of the vascular system is destroyed at the base of the the tree, the supply of water and nutrients to the entire tree will be affected. The larva bore into the cambium layer beneath the bark and feed. Peach Tree Borers are usually more damaging than the Lesser Peach Tree Borer, as they lay their eggs at the base of the trunk at or near ground level. Sap with no sawdust is likely caused by disease organisms. The sap oozing from the trunk will contain sawdust and frass (excrement) in trees infested by borers. They target trees already weakened by other factors. Weakened trees are also more prone to damage, as are trees with mechanical damage, disease organisms or previous borer activity. Young trees are especially vulnerable during establishment. The larvae hatch and bore into the cambium layer, just below the tree’s bark, where they feed on vascular tissue. Eggs are deposited in March to May, and again in August to September on the trunk of peach trees near the soil line. Peach Tree Borers are the larvae of a “clear wing moth” that has translucent wings and resemble wasps. Peach Tree Borers are seldom a problem with healthy trees, but are attracted to damaged areas of the tree caused by poor cultural practices. Insects: Borer insects, such as the Peach Tree Borer and the Lesser Peach Tree Borer, lay eggs on tree bark and the larvae bore into the trunk. Remove severely affected branches or entire trees to prevent spread. Sterilize pruners with a 10% bleach solution after pruning each tree. Maintain tree health with proper fertilization and watering and avoid pruning between October and January. Pruning closer to the time the tree “leafs-out” in late winter to early spring is the preferred timing for pruning.Īpplying bactericidal chemicals is not recommended or effective for prevention or treatment of this disease. Avoid poorly drained soils, mechanical injury, improper pruning practices. Trees that are 2-8 years old and stressed are the most susceptible. Bacterial Canker can also cause leaf spots that begin as a dark purple lesion, then a “shot hole” condition when the center drops out. There may be an increase in formation of water sprouts (shoots growing from the base of the trunk). Sap will be clear with no sawdust or frass. Gummosis has a distinctive sour-smelling odor when it is caused by bacteria. Cankers (sunken tissue) may occur on larger branches and trunks. Symptoms vary, but typically appear in the spring when infected twigs die. Bacteria may also enter the tree through borer holes. Entry is usually through injury sites or pruning cuts. These practices may extend the life of the tree.ĭisease: Pseudomonas bacterial canker affects weakened trees. It is important to keep the tree as healthy as possible through proper pruning, fertilization, and watering practices. Trees do not regenerate vascular tissue once it has been destroyed. Unfortunately, once the damage is done, there is little that can be done to correct the damage. The injury to the tree provides an opening for disease to enter the tree. Mechanical injury: Damage to trunk from mowers and string trimmers, deer rubs, improper pruning cuts, or pruning in fall and winter when disease is active can contribute to the cause of gummosis. Do not plant fruit trees in poor, thin soil. Avoid planting in heavy soils or light sandy soils that do not hold moisture. It is necessary to determine the cause of the stress in order to mitigate future damage to the tree.Įnvironmental stress: Compacted soils, poorly drained soils, light sandy soils, use of weed and feed or other herbicides nearby, and winter injury can all contribute to the cause of gummosis, as can lack of irrigation under the canopy.Ĭorrect any environmental stresses that you can. Anything that stresses the tree can be a causal factor. It is important to understand that the term “gummosis” is a symptom, not a cause of a tree ailment. Gummosis is a term that refers to the presence of amber-colored sap oozing from the trunk or branches of a tree.
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