Prevention and control of lily blight

Symptoms: the whole plant (including floral organ, leaf, stem, stem base, bulb, root) can occur. The susceptible flower organ withered and withered, and white mildew grew on it; the leaves appeared at the beginning of water immersion, and then withered; the stem and stem base tissue initially appeared water-immersed spots, and then turned brown, necrotic, narrowed, and completely withered above the infected parts. The bulb browned and necrotic. Root browning, spoilage pathogen: the pathogen belongs to Phytophthora fungal parasitic Phytophthora (PhytophthoraparasiticaDast). The hyphae are colorless and septum-free. No haustorium was produced, and the hyphae penetrated directly into the host cells to absorb nutrients. Hyphae and a large number of sporangia were produced in the later stage. The cyst pedicel is mostly unbranched, and the sporangium is terminal and unispore, round. There is a nipple process at the top. Multiple oval zoospores are produced when sporangia germinate.

Route of infection:

1. The pathogen mainly overwintered with the diseased and residual plants in the soil, and the oospores splashed on the plants with Rain Water or irrigation water in the coming year, and the germinating germ tube invaded the host.

two。 Later, the disease spot produces a large number of sporangia, and the sporangium produces zoospores, which spread through Rain Water, irrigation water and so on.

Disease conditions: bulb carrying bacteria, continuous precipitation, poor drainage.

Prevention and control methods:

1. Choose healthy bulbs, set up rain-proof facilities and pay attention to drainage.

2. Chemical protection before the rainy season. At the initial stage of the disease, 25% metalaxyl 800 times solution, 58% metalaxyl manganese zinc 500 times solution, 40% aluminum ethyl phosphate 200 times solution, 64% poison alum wettable powder 500 times solution, or 77% wettable particulate powder 500 times solution. Spray once every 7 to 10 days, 2 times in a row. It is also possible to spray 72% urea manganese zinc (Kakangling) wettable powder 800 times or 72% DuPont Klu or 72% grams of cyanide wettable powder 800 times or 1000 times in time at the beginning of the disease, and 56% of the landscape dispersed micro-granules 800 times.