anthracnose

Tree diseases continue to be a problem throughout the country causing harm and threatening otherwise healthy trees. The Davey Tree Expert Company’s Diagnostic Laboratory identified the top three most common diseases they diagnosed over the course of 2020. These top three diseases affect the appearance of a variety of trees from conifers to deciduous, and, if combined with other factors, can be deadly for a tree. Keep a close eye on these diseases in your area because they can be anywhere, and they aren’t going away in 2021.   Rhizosphaera Needle Cast. The number one most common disease of 2020 and the most problematic of the three diseases, Rhizosphaera Needle Cast is a fungal disease that can be found affecting conifer trees across North America. Spruce trees are the most susceptible to this disease, as well as fir, pine, and hemlock species. Alone, Rhizosphaera Needle Cast will most likely not kill a tree after one season—but in combination with other elements, it can be a contributing factor that results in tree death or decline. There are simple visual symptoms one can look for that help determine if a tree has Rhizosphaera Needle Cast without a diagnosis from a lab. These include excessive needle drop, thinning of the canopy (especially from the bottom up), and a purple to dark brown color of the inner needles. Fortunately, there is a treatment for Rhizosphaera Needle Cast. Since it’s a fungal disease, a fungicide application can be used as a preventive to reduce infection ...