Matters needing attention in replenishing water with edible fungi, two common diseases of Magnolia

Bacterial soft rot

The disease mainly occurs in leaves and stems. Most of the leaves start from the base of the leaves, the diseased parts are dull, the front and back are dark green, water stains, and irregular, and seriously develop upward along the leaf veins, resulting in rot and softening and drooping of the diseased leaves.

Pathogen and characteristics of disease

The pathogen is Eucella. The bacteria were solitary, rod-shaped, with multiple flagella, capsular, and Gram staining negative. The optimum temperature for the growth of the pathogen was 28 ℃. The bacteria could produce acid and gas by fermentation of glucose, sucrose, xylose, fructose and sorbitol. It lives on the diseased body in the soil and is spread by Rain Water, irrigation water, insects and humans, and invades the host from the wound. Under the condition of high temperature, high humidity and poor ventilation, the disease is serious. There were more cases from June to September.

Prevention and cure method

① in horticulture operation as far as possible to avoid causing wounds, promote plant growth, control pests to reduce insect damage.

② ventilates the room regularly and reduces humidity.

In the early stage of ③, streptomycin or oxytetracycline 200 to 1000ppm can be used to spray the plant disease department.

Leaf spot disease

The main symptoms of the disease were damaged leaves. Leaves primary brown spots, and then expand and form irregular large spots, light brown to grayish brown, the edge is slightly raised, and small black spots will be produced on the disease spots in the later stage.

Pathogen and occurrence characteristics

The conidia of the pathogen are oblate and dark brown, while the conidia are oval and unicellular. The pathogen lives in the disabled body and invades from the plant wound like the bacterial soft rot of Cymbidium. The disease can occur all year round in the greenhouse, poor ventilation, too little light, too high humidity, which is not conducive to plant growth, thus reducing disease resistance: watering on the leaves is conducive to the growth and development of bacteria, these are very easy to occur, and the disease is more serious from July to November.

Prevention and cure method

① cut off the diseased leaves and clean the leaves at any time to reduce the chance of bacterial infection.

When ② changes pots in spring, it should be applied sufficient base fertilizer and placed in the shade shed, and more topdressing should be applied during the growth period to keep the soil moist and well ventilated. There is usually no fertilization in summer.

When ③ occurs, it can be sprayed with 1000 times of thiophanate methyl.