What are the disease control methods for lotus root cultivation?
How do you control diseases when growing lotus root? What are the techniques? Lotus root is a high-yield, high-efficiency aquatic economic crop and a vegetable variety commonly eaten by the general public. It is widely cultivated in various regions, and with industrial restructuring in various places, its cultivation area has been continuously expanding. In recent years, lotus root diseases have become increasingly serious and have...
How do you control diseases when growing lotus root? What are the techniques?
Lotus root is a high-yield, high-efficiency aquatic economic crop and a vegetable variety commonly eaten by the general public. It is widely cultivated in various regions, and with industrial restructuring in various places, its cultivation area has been continuously expanding. In recent years, lotus root diseases have become increasingly serious and have become a major obstacle to the development of lotus root production.
I. Common diseases of lotus root
1. Lotus root rot, also known as black root disease and lotus root plague. It is the number one disease in lotus root production. It is generally prone to occur in old lotus root fields with shallow plough layers and shallow water and in continuously cropped fields, affecting lotus root formation and reducing yield. It is a lotus root disease caused by infection with a corm-like fungus, mainly damaging underground stems, aboveground leaves and leaf surfaces. The leaves produced by diseased stems are light green in color, begin to develop brown blight from the leaf margins, and the petioles finally die. The pathogen mostly invades through wounds, absorbing roots or growing points, and the pathogen spreads with flowing water irrigation.
2. Lotus root leaf blight is the second major disease on lotus root, and the pathogen is a pathogenic fungus of the genus Sphaerotheca. It mainly damages lotus leaves. Pale yellow lesions first appear on the leaf margins, then gradually spread toward the middle of the leaf, turning yellow-brown, and finally spread from the mesophyll to the leaf veins until the disease develops. When the lotus field has insufficient fertility, the disease is severe.
3. Lotus root leaf spot mainly damages leaves and can sometimes also occur on petioles. It is caused by the pathogenic fungus of the genus Isaria.
II. Comprehensive control of lotus root diseases
1. Implement 2-3 year crop rotation. In particular, paddy-upland rotation plays an important role in reducing diseases.
2. Select disease-free seed lotus roots for planting. Seed lotus roots carrying pathogens are the main source of infection for rot. To prevent this disease, the key is to select healthy plants from disease-free lotus root fields as seed lotus roots to eliminate the source of infection. Before planting lotus roots, spray the seed lotus roots with a 800-fold solution of 50% carbendazim or thiophanate-methyl, or a 800-fold solution of 75% chlorothalonil wettable powder, then cover them tightly with plastic film and seal them for 24 hours, then dry them in the shade before sowing.
3. Remove diseased plants. Thoroughly remove diseased plants and diseased residues from diseased lotus root fields, and bury them deeply or burn them in a centralized manner. Before planting, apply 50-100 kg of quicklime per mu, which both sterilizes and cleans the field and accelerates the decomposition of organic fertilizer.
4. Fertilize reasonably. Base fertilizer should be mainly organic fertilizer, and the fertilizer must be fully decomposed. For soil with high acidity and strong reducing properties, lime should be applied heavily, and lime should be applied early and in larger amounts. During the growing period, pay attention to the combined application of nitrogen and phosphate fertilizers. Where conditions permit, increase the application of silicon fertilizer, advocate supplemental application of microfertilizers such as boron, zinc and molybdenum, and do not apply chemical nitrogen fertilizer alone, so as to improve the disease resistance of the plants.
5. Manage water scientifically. During the disease period, irrigate with deep water to lower the soil temperature and inhibit pathogen reproduction. Seed lotus root fields should be kept soaked in deep water every day, and must not be drained or winter-ploughed and sun-dried. Non-seed fields should, after harvesting lotus seeds, have all lotus stems cut and the field ploughed or the lotus roots dug, and it is best to plant one season of winter crops. Even if no winter crop is planted, the field should still be ploughed and irrigated to soak the field, reducing pathogens carried in the soil and diseased residues.
6. Apply pesticides in time for control. In the early stage of the disease, use a 600-800 fold solution of 50% carbendazim wettable powder, or a 800-1000 fold solution of 50% thiophanate wettable powder, or spray a 600-fold solution of 50% carbendazim wettable powder plus a 600-fold solution of 75% chlorothalonil. Alternatively, mix 500 g of the above mixed powder with 25-30 kg of fine soil, pile and seal for 3-4 hours, then spread it under the lotus root crowns in the shallow water layer. After 2-3 days, use a 600-fold solution of the above mixture, or a 800-fold solution of 70% thiophanate-methyl, or a 200-fold solution of carbendazim mixed with a 4000-fold solution of "402", and spray the leaf surfaces or petioles, spraying 2-3 times consecutively, which can effectively reduce or control the spread of this disease.
Click to see more lotus root cultivation techniques
Click to see more vegetable cultivation techniques