条件筛选
-
Symptoms and Control Methods of Pythium Root Rot in Tulips
The disease can be caused by Pythium ultimum, Pythium irregulare, and Pythium intermedium, all of which are fungi belonging to the oomycetes. The pathogen overwinters in diseased bulbs, diseased roots, and soil, and often spreads with the movement of diseased soil. High soil temperature, delayed drainage after rain, and prolonged moisture retention make the disease more likely to occur. Symptoms: At the early stage of the disease, translucent water-soaked spots appear on the roots, and after expansion they cause browning of the vascular tissue, resulting in root rot. After the bulb is infected, gray spots appear around the base of the bulb with brown edges. In severe cases, the bulb becomes soft and rotted. Planting diseased bulbs