The peach trees in your home garden are vulnerable to fungal diseases that have the power to severely damage the trunks and potentially take the lives of your prized trees. To avoid injury and loss of peach trees and their fruit, familiarize yourself with the types of fungi that attack stone fruit trees and what to do should your tree fall ill.
Vigorous peach trees are much more likely than injured or stressed trees to fight off fungal infections that mar their trunks and cost trees their health. Waterlogged soil and wet surfaces attract fungi that cause trunk rot on peach trees, so grow your trees in areas that offer full sunlight to dry up excess moisture. Peach trees thrive in well-drained loam soil, according to the Ohio State University Extension.
Phytophthora collar rot is a fungal infection of peach trees that leads to trunk rot, according to the University of Kentucky Cooperative Extension Service. This problem is caused by the fungi Phytophthora cactorum, P. cambivora and P. cryptogea among other related Phytophthora species. Armillaria root rot, also referred to as shoestring root rot, causes root and trunk rot on peach trees, as well. It is caused by the fungus Armillaria mellea, sometimes referred to as the honey mushroom. Both diseases result from sporadically spread soil-borne pathogens that generally enter peach trees through their roots.
Phythophthora collar rot results in trunk rot with the display of cankers, or dying lesions of plant tissue, near its base. Cankers sink into the trunk's tissue and become a darker hue. The interior wood and bark change from a healthy white to a red/brown color. Roots become infected as well, leading to stunted growth, severe decline, leaf discoloration and abundantly colored stunted fruit. When in the presence of waterlogged soil, trees may die because they cannot absorb necessary water and oxygen, according to the University of Kentucky Cooperative Extension Service. Armillaria root rot of peach trees causes the growth of honey-hued mushrooms on the base of the trunk, as well as the appearance that infected wood has been bleached. Wood softens and becomes stringy as it decays beneath the bark. Your peach tree may experience extreme decline or death.
Natural control methods for phythophthora collar rot on peach tree trunks include providing extremely well-drained soil and level planting grounds. For natural control of armillaria root rot, do not plant a peach tree if the disease has already been present as a preventive measure and keep your trees as vigorous as possible through proper care. For both problems, remove and destroy affected plant parts to prevent disease spread. Always sanitize pruning tools between each cut and from one plant to the next to prevent the transfer of pathogens.
Though no chemical control method is recommended for armillaria root rot problems on peach tree trunks, you may employ a preventive chemical control for phytophthora collar rot. Unfortunately, fungicides do not cure the problem but only help prevent it from forming. As it is difficult to predict whether or not an infection will occur, prevention may be tricky. The University of Kentucky Cooperative Extension Service suggests utilizing costly chemicals only on poorly drained sites that are highly vulnerable to infection. Use a fungicide with the active ingredient mefanoxam on soil after harvest during the autumn season. For best application, contact a licensed professional.