Control of lily leaf blight

Symptoms: round or oval disease spots appear on the leaves, varying in size and more than 2mm in length. Light yellow to light brown. In some varieties, the spot is light brown, surrounded by a clear reddish-purple edge, and in wet conditions, the spot is quickly covered with gray mold. When the disease spot is dry, it becomes thin, fragile, transparent and generally grayish white. When serious, the whole leaf withered and died. When the stem is infected, it is rotten and broken from the infection place, and the bud turns brown and rotten. When the flowers are brown and moist, they quickly turn into a sticky mass and are covered with a gray mildew layer. When the young plants are infected, the growing point usually dies. But the plant can grow again in summer.

Pathogen: the pathogen is Botrytiselliptica (Berkeley) Cooke. The conidia are oval. Sometimes Botrytis cinerea (BotrytiscinereaPers.) can also damage lilies, but it mainly causes flower rot.

Route of infection: the pathogen overwinters with hyphae or sclerotia on the remnants of fallen diseased tissue, and produces conidia infection in the following year, which can be infected repeatedly; it is easy to occur when the greenhouse is too wet. When the plant is too dense, the disease is serious, and the disease is serious when nitrogen fertilizer is applied.

Prevention and control methods:

The main results are as follows: 1. In the autumn of horticulture, the aboveground parts of the plants cultivated outdoors are removed and destroyed, and the diseased leaves are removed in the first disease to reduce the source of infection.

2. The greenhouse should be ventilated and illuminated enough, and watering should be carried out when the water on the leaves is easy to dry, preferably from the edges to avoid wetting the leaves.

3. 50% carbendazim or 70% carbendazim or 70% methyl thiophanate wettable powder 500 times can be used for drug control. If necessary, 50% carbendazim or 50% prophylaxis and 50% nonglide wettable powder 1000 / 1500 times plus 80% carbendazim 600 times solution has a good effect. The liquid is sprayed at a rate of 40kg to 50kg every 667m 2. Focus on spraying new leaves and the surrounding soil surface, spray twice in a row.