Blight of garlic leaves

Leaf blight is an important disease of green garlic. When it is serious, it causes the whole leaf to die and affects the yield.

First, symptom identification of the disease is mainly harmful to leaves and pedicels. Most of the leaves were killed, starting from the tip of the leaf, gradually developing to the base of the leaf, and spreading from the bottom to the upper. Pale small round spots appear at first, and then expand into oval or irregular gray-white or grayish-brown spots, the disease has black mildew, in severe cases. The whole leaf withered. When the pedicel is killed, it is easy to break from the disease. finally, there are many small black spots scattered on the disease spot. Main points of identification: black mildew or black particles are found in the leaves and pedicels, and when the disease is serious, the diseased leaves die.

Second, the law of the disease.

1. The pathogen garlic leaf blight is caused by the infection of ascomycetes subphyla. Conidiophores protruding from stomata, slightly curved, conidia solitary, ovoid or oval, gray or dark yellowish brown. The ascomycetes are spherical and contain 30 ascomycetes. The ascomycetes are generally long oval in shape, containing 8 ascospores, and the ascospores are yellowish brown.

2. The infection circulatory bacteria overwintered mainly as ascomycetes in the soil with the disease remains. When the environmental conditions were suitable in the second year, ascospores were emitted to cause primary infection. After the onset of the disease, conidia are produced in the disease department, which are transmitted and re-infected.