At the Plant Clinic, we have certainly seen a variety of problems so far this season. This range is a direct reflection of the rain and temperature differentials over the state. |
Root rots identified from water mold fungi (wet situations) include Pythium and Phytophthora. Watch for more of these in the wet areas of the state.
We've also seen dry-weather disease problems, including powdery mildew and Rhizoctonia root rot. As dry areas heat up, we can expect more Rhizoctonia problems on stems, especially near the soil line. Although apple scab and anthracnose have been seen, their incidence this year has been much lower than usual due to the dry weather when leaves emerged. Generally the leaf-spotting diseases have been less severe this year. Fire blight commonly infects in warm, wet seasons and has been confirmed on pear and crabapple. Verticillium wilt has been isolated from maple and ash. Pinewood nematodes have been spotted and confirmed on a few Scotch pines. Oak wilt has been confirmed on several oaks in the red/black oak group. The Dutch elm disease fungus has been isolated from many elms.
Plenty of diseases are working in the landscape, some serious and some affecting only aesthetics. Keep an eye out for problems. (Nancy Pataky)