Anthracnose (leaf blight) is a fungus that winters on twig tissue on the tree. In the spring, spores are transported to new buds and shoots. The disease is enhanced by cool, wet conditions. Infected leaves develop tan to reddish brown lesions that extend along the veins of the leaf (see image). Anthracnose susceptible trees include oak, ash, maple, elm, hickory, walnut, birch, linden, sycamore, dogwood. Sycamore white oak and dogwood are particularly susceptible to anthracnose.
Tan to reddish brown lesions that extend along the veins and edges of the leaf, considerable defoliation, sometimes with complete leaf loss.
Tree Injection with PHOSPHO-jet or Alamo
Arborjet recommends a tree injection of either PHOSPHO-jet or Alamo. Injecting fugicides directly into trees is fast, effective, and safer for the environment. PHOSPHO-jet deteriorates fungal cells while eliciting a plant health response from the tree. PHOSPHO-jet will promote stronger, healthier tree cells, promote root development, and incerase helath to trigger the tree’s natural defense mechanisms. Alamo will have more direct and aggressive activity against the fungus itself and is recommended if infection is chronic or particularly severe. In the Spring, the recommended delivery system is the Tree I.V. but in the Fall the QUIK-jet can be used. PHOSPHO-jet can be applied in undiluted form.
When To Treat
Generally, the best seasons for tree injection are fall and spring. The environmental conditions that favor uptake are moderate temperatures, adequate soil moisture, and high humidity. Soil temperature should be above 40 degrees. Tree health will influence uptake time.
Trees may still defoliate despite the treatment with either of these products. However, we recommend treatments that enhance tree health. Our research is demonstrating that infected trees micro-infused with PHOSPHO-jet are more resistant to infection in the first place and recover from infection more quickly.