Prevention and treatment method of leek rot

From a fundamental point of view to understand the onset symptoms and disease conditions of amaranth rot disease, in order to make the pesticides correct, and achieve good control effects.
Symptoms mainly affect the leaves, which are divided into three types: white point type, dry point type and wet rot type.
The white-point and dry-tip type initially produce white or light gray-brown small spots on the front or back of the leaf, which develop downward from the tip of the leaf. The lesions are diamond-shaped or elliptical, sometimes merge with each other to form plaques, causing half or full leaf When the humidity is high, there is a sparse mold layer on the surface of the dead leaves.
The wet rot type occurs when the temperature is high, no white spots are formed on the leaves, and the surface of the dead leaves is densely ash to green velvet mold with a musty smell.
The dry tip type rots downward from the mouth of the cutting knife. It becomes light green after the first water immersion, and has a brown wheel pattern. The lesions are mostly semi-circular or "V" shaped after being spread, and can be extended downward 2-- 3 cm, yellowish brown, when the humidity is high, the surface is grayish brown or grayish green.
In the pandemic or in the storage and transportation of amaranth, the diseased leaves have symptoms of wet rot, completely wet and rot, and the surface is gray mold, so it is also called amaranth rot.
Incidence condition

The pathogen can be spread to new leaves through irrigation, farming operations, etc., and the disease occurs in the case of high temperature and high humidity.
The control method is controlled by temperature, humidity, timely ventilation and dehumidification to prevent excessive humidity in the shed. According to the weather changes, a certain amount of shed film ventilation is opened at noon to reduce the humidity, so that the relative humidity in the shed is kept below 75%, but the bottom wind is strictly prohibited.
After cleaning the shed leeks, the diseased bodies are removed in time, and the diseased leaves and diseased plants are carried out of the shed and buried or burned to prevent the spread of germs.
The chemical spray shall be sprayed once before each cultivating amaranth. 50% carbendazim or 70% carbendazim WP 500 times, or 50% kelly WP, 50% Wet powder 1000--1500 times liquid. Spray 40--50 kg of liquid per acre, focus on spraying the soil surface around the new leaves, and spray 2 times continuously.
In the early stage of the smog chamber, the smoke method or the dust method can be used. The 10% speed Keling smoke agent can be used, 200-250 grams per mu, or 45% chlorothalonil smoke agent is 250 grams per mu, and 6-8 pieces can be distributed. Point, ignite with a dark fire, close the shed, and smoke for 3 to 4 hours.
Dust dust method spray 10% fungicide dust in the evening, or 5% chlorothalonil dust, 1000g per acre, 9--11 days, continuous or alternate with other control methods 2-- 3 times.