What are the latest control methods for wild rice stem smut?
Wild rice stem, also called gaosun, is a vegetable grown in swamps, mud, and paddy fields. Because wild rice stem is grown in a moist environment, it is prone to many diseases and pests, and the disease that mainly damages the edible part is the smut I am going to introduce to you now. Affected wild rice stems all develop large amounts of black powder, the damage is severe, and yield drops sharply. How to prevent its occurrence and spread, and how to treat it, is the focus of our article.
I. Symptoms of damage
It mainly damages the leaf sheath and the swollen stem. When the leaf sheath is affected, green small round spots appear, which then gradually grow into oval tumor-like protrusions, after which large numbers of black spore masses form, appearing as black powder. The smut fungus bulges the affected intermediate tissues throughout the wild rice stem, making the wild rice stem short and thick, and the surface shoots furrowed.
II. Pathogen infection
The cause of the damage is the wild rice stem smut fungus, which mainly overwinters as perennial mycelium in diseased plant tissues and soil. It occurs in many places nationwide, regardless of north or south, has strong reproductive capacity, and continues to cause disease under high temperature and high humidity, becoming widespread over large areas.
III. Control methods
1. Crop rotation
Fields where the disease has occurred should be rotated after harvest in that season with upland vegetables; of course, only vegetables not infected by this disease can be used for rotation.
2. Disinfection
Seedlings to be planted must pass quarantine, or be seedlings cultivated through virus-free techniques, before they can finally be planted. In addition, before planting, sterilizing agents can be sprayed in the field to prevent infection by pathogens present in the soil. Generally, 50% carbendazim wettable powder at 800 times dilution can be used for spraying.
3. Management
Old leaves at the base can be removed to prevent invasion and damage through the leaf sheaths in the moist environment at the base. Excessive tillers should be handled promptly at the early stage, so that appropriate spacing is maintained in the field; this can reduce environmental humidity and lower the possibility of disease occurrence. Long-term continuous use of sufficient compound fertilizer can resist the disease. Irrigate with shallow water during the tillering stage, and by the high temperatures of summer irrigate deeply to protect the roots; later, just keep the mud moist.
4. Spraying
Before occurrence, spray Bordeaux mixture as a protective agent once a month for prevention. At the early stage of occurrence, spray the whole plant with 75% chlorothalonil wettable powder at 600 times solution, spraying once every three days, for about 2 subsequent sprays; the number of sprays and the pesticide and dosage can be adjusted according to the condition. When the disease is epidemic, use 25% carbendazim wettable powder and 75% chlorothalonil wettable powder at 600 times solution alternately for spraying, spraying once every 7 days, for 3-4 consecutive treatments; during the rainy season, increase the number of sprays.
For the occurrence of wild rice stem smut, do not provide conditions for the pathogen to develop. In addition, prevention first and quarantine are also very important; only lastly comes timely medication after disease onset. Do not use the same pesticide repeatedly; use them alternately. In short, the content of this article is provided for reference. Thank you for reading.