Botrytis cinerea of Luffa is easy to occur in high humidity and low temperature environment. When germs infect young fruits, they usually invade from the residual flowers, rot the petals first, then invade inward, and the damaged parts are soaked in water and then turn grayish brown. Young loofah was quickly infected, spread outward in a humid environment, and quickly infected the whole melon shed. After the rapid spread of botrytis cinerea, the seedlings and leaves of Luffa will be attacked by the pathogen. After the leaves are infected with Botrytis cinerea, irregular gray or reddish brown spots will appear on the leaves.
Botrytis cinerea of Luffa belongs to fungal diseases. The injured loofah has a layer of gray mold, and the young loofah shrinks and softens and then rots. Mold appeared in the diseased spot, which was gray at first. With the aggravation of the disease, the injured part turns pale gray, and the melon stops growing or falling off. Bacteria can be spread by wind, rain and water. In spring, the temperature reaches 20 degrees, the mycelium is active, and the towel gourd is also easily infected by germs.
The prevention of botrytis cinerea is the main method, and the specific control methods are as follows:
1, minimize continuous cropping of loofah and reduce humidity. The towel gourd seedlings planted in the last crop remained in the soil and became the initial source of infection. So try not to repeat the planting of loofah. If it is repeated, the remaining branches and leaves should be removed to reduce the source of infection. Pay attention to the water used for loofah. The air is humid, which is easy to cause diseases, especially the loofah planted in the greenhouse. The poor ventilation and high humidity in the greenhouse have contributed to the diseases of loofah. It is necessary to ventilate frequently to eliminate moisture, and cover the greenhouse and the ground with plastic film to reduce the moisture volatilized from the soil into the air.
2. Cultivate strong seedlings. Luffa likes loose and fertile soil. Planting in soil with organic matter content above 5% is easy to obtain higher yield. When planting, apply one kilogram of fully decomposed farm manure beside each towel gourd, mix100g of beneficial microbial inoculum, and spray 0.2% potassium dihydrogen phosphate aqueous solution+after two leaves of pumpkin seedlings are combined. Planting watermelon and cultivating strong seedlings is one of the effective ways to improve disease resistance, which should be paid enough attention to.
3. Chemical control: After the loofah is planted, 800 times of thiophanate-methyl and brassinolide solution can be sprayed regularly as a preventive medicine once a week. At the initial stage of botrytis cinerea of Luffa, 600 times sterilized alum +800 times chlorothalonil wettable powder+brassinolide can be sprayed.