The hosts for Leucostoma canker include stone fruits such as cultivated peach, plum, prune, cherry (Prunus spp.

Light and dark concentric circles of narcotic tissue characterize this symptom, occurring near buds killed by cold or on leaf scars.

If fungal growth persists without treatment, scaffold limbs and large branches will likely become invaded within a short time frame.

This gum darkens as time passes, gradually leading to the drying and cracking of bark; thus exposing the blackened tissue below.

However, the Leucostoma generally reinvades the tissue late in the growing season while the tree switches into dormancy.

[7] Although the Leucostoma pathogen can undergo sexual stages, the asexual cycle is far more important for disease development.

Environmental cues, such as cool, moist weather in the early spring, cause conidia to be released from pycnidia in sticky masses.

The fungus is incapable of invading healthy bark and must enter the tree through injured, dying, or dead tissues.

As the temperature rises above 50 degrees Fahrenheit, the tree actively starts to grow and a callus is usually formed around the canker.

As a result, vulnerable tissues are at risk of initial invasion throughout most parts of the year, although it most commonly occurs in autumn and spring following winter injury and leaf scars.

Leucostoma canker can be found in the Northeastern United States, from the cooler regions surrounding Lake Ontario to the warmer areas in the lower Hudson Valley.

[1] The spread of disease is favored in cool, wet, and humid conditions in late fall or early spring when conidia are most abundant.

Control of Leucostoma Canker is possible through a combination of pest and crop management techniques following the life cycles of the trees.

Prune trees appropriately and at the correct time when buds start to break to promote wide angled branching.

Infection at pruning sites is less common when done during late spring because of the smaller amount of inoculum present at this time.

Training trees during the first season to have branches develop wide crotch angles to sustain long orchard life.

As limbs with cankers die or break off due to the stress of holding fruit, economic losses add.