Plant Disease Diagnostic Lab Highlights

The following plant disease highlights from the University of Kentucky Plant Disease Diagnostic Laboratories represent recent sample submissions from field crops, fruit, vegetables, and ornamentals.

Figure 1: The “timber rot” disease of tomato, also known as Sclerotinia stem rot or white mold, can affect fruit as well as stems. Infected fruits become soft and watery. Dark fungal survival structures (sclerotia) form on rotting fruits; in the image above, sclerotia are visible forming a ring around the fruit stem. (Photo: Julie Beale, UK)

Recent diagnostic samples of agronomic crops have included white mold (Sclerotinia) on alfalfa; Pythium root rot, Rhizoctonia damping-off and cold injury on tobacco transplants; stripe rust, speckled leaf blotch, powdery mildew, bacterial streak, and freeze injury on wheat.

On fruit and vegetable crops, we have diagnosed cane blight on blackberry; leaf scorch (Diplocarpon) and the black root rot complex on strawberry; leaf curl on peach; black knot on plum; Pythium root rot on cabbage, tomato, and pepper transplants; timber rot (Figure 1), Botrytis blight, and tomato spotted wilt virus on tomato.

On landscape and turf samples, we have seen Pythium root rot on geranium; black root rot on petunia; bacterial blight on peony; black root rot on holly; rosette disease on rose; Rhizosphaera needle cast on spruce; Dothistroma needle blight on pine; Cercospora blight on Leyland cypress; Volutella canker on boxwood; Nectria canker on mimosa; powdery mildew on fescue; and dollar spot on bentgrass.

 

By Julie Beale and Brenda Kennedy, Plant Disease Diagnosticians

 

 

Posted in Plant Disease Diagnostic Lab