Although the diagnostic season is not yet in full swing, several greenhouse samples have been received recently. In addition, unseasonably warm weather during most of January and February has prompted submission of more landscape samples than we typically see in winter.
On greenhouse crops, we have diagnosed tomato spotted wilt virus, Pythium root rot, Botrytis blight, mechanical injuries and nutritional disorders on tomato; and cold injury on petunia.
On landscape plants, we have seen numerous cases of Rhizosphaera needle cast on spruce; Dothistroma needle blight and brown spot needle blight on pine; Volutella canker and leaf miner injury symptoms on boxwood; and abiotic decline on arborvitae, chamaecyparis and pine.
By Julie Beale and Brenda Kennedy, Plant Disease Diagnosticians