Almond trees, as well as all stone fruit trees, are under threat of potentially fatal Armillaria root rot. Due to the ease with which the disease spreads, as well as the rapid onset of injury, getting to know the details of this problem will help you to avoid extensive damage to your home garden. Become familiar with what signs to watch for and effective management to keep your trees vigorous.
Vigorous trees are always less likely to become infected with a fungal infection and more prepared to regain health if infection occurs. Plant almond trees in locations that provide full sunlight for successful fruit growth and vigor, according to the AgriLife Extension Texas A&M System. Grow in moist, well-drained soil and avoid waterlogged conditions that create an ideal environment for the proliferation of fungi responsible for root rot.
Almond tree root rot is caused by the fungus Armillaria mellea that also affects other stone fruit trees like peaches. Also referred to as shoestring root rot, pathogens are soil-borne and make up approximately 20 different species, according to the University of Illinois Extension IPM. Once fungi come into contact with the roots of the almond tree, they invade roots and the trunk.
In general, the roots of infected trees grow toward infected sites, according to the University of Illinois Extension IPM. Growing other highly susceptible trees dramatically increases the chance for infection of your almond tree and for the continued infection of your landscape's soil. Aside from stone fruit trees, other vulnerable trees include, but are not limited to, birches, dogwoods, pines, poplars, sycamores and tuliptrees. When planning your garden or replanting after the loss of a tree, avoid these highly susceptible species to prevent further problems. Instead, choose trees like boxelders, pecans and Southern magnolias that are known for their resistance to root rot that affects almond trees.
Root rot of almond trees results in the display of yellow to white fungal growths between tree bark and interior wood, according to the University of California IPM Online. Roots decay and foliage often become sparse and faded in color as developing leaves experience stunted growth or simply fail to show up at all. These effects of Armillaria root rot are often followed by tree death when temperatures begin to rise.
For control of almond tree root rot, soil fumigation is necessary, according to the University of California IPM Online. Remove and destroy affected plant parts before fumigating. Apply chemicals during drier periods as excessive moisture inhibits its effectiveness. Choose a fumigant with the active ingredient sodium tetrathiocarbonate. For safest and most successful application, contact a licensed professional.