Changting County has a long history of betelnut cultivation. The betel nut planted is of unique quality, with fragrant meat powder and loose taste. It is popular among Fujian, Guangdong and Hong Kong and Macaw people. At present, the Changting betel nut has an annual planting area of ​​more than 4000hm2, which has become an important industry for local farmers to generate income. Soft rot is one of the most important diseases of Changting betel nut. In recent years, the damage has become increasingly serious and the loss is huge. In 2010, the area was nearly 1000 hm2. The incidence of strains was generally 3% to 15%, and the weight was more than 55%. The harvest was a serious threat to the betel nut industry. From 2008 to 2010, we conducted a comprehensive research on prevention and control technology, and achieved very good results, effectively reducing the damage caused by the soft rot of the betel nut.
1 symptoms
Betel nut soft rot mainly damages the leaves, petiole base and underground bulbs. The leaves were infected and they initially showed wet and dark green spots, and the tissue was rotted after expansion. The pathogens invaded the veins and petioles along the catheters, resulting in water-streaked stripe spots, which caused the base of the petiole to rot; the bulbs became infected. First the new leaves appeared wilting at noon, and then gradually Spread to the whole plant with yellowish wilting and withered, watery stains on the surface of the diseased tuberculosis area appear dark spots, and then rot inside, the bulbs quickly soften, corrupt, appear mucus and emit foul odor, and eventually the whole plant withered to death.
2 pathogens
The pathogen Erwiniacarotovota subsp. Carotovora (Jones) Berseyetal. Carrot soft Erwinia carrot soft rot pathogenic type, is a bacterium. The colonies were grayish white and round on the medium. The cells are short-stemmed, with sizes ranging from 0.5 to 1.02.2 to 3.0 μm, with 2 to 8 weekly flagella, no decidua, no spores, and Gram negative staining.
3 Transmission routes and conditions
The pathogens overwinter in the soil or bulbs with diseased tissue. The pathogens invade from wounds and stomata. The wounds are mainly natural cracks, insect lesions, scars, and mechanical wounds. They are spread by insects in the field and spread by irrigation water to re-infect. The onset temperature range is 4~38°C, and the optimum temperature is 25~30°C. It is prone to outbreak when severe weather such as strong winds and heavy rain, high temperature and high humidity changes. Generally, continuous cropping, dense planting, low topography, poor drainage, low-lying water, high humidity in the field, nitrogen-enriched greens, and re-emergence of pests are more serious.
4 comprehensive prevention and control technology
Betel nut soft rot is a bacterial disease, and Changting County entered the peak period in late June. Prevention and control should strictly implement the principle of "prevention as the main, comprehensive prevention and control", adopt methods of combining agricultural cultivation, physical manufactory, and chemical agents, combine prevention and treatment, prevent prevention and treatment, early treatment is more important than late treatment, and pharmaceutical selection is highly efficient. Low toxicity and low residue pesticides.
4.1 Plot selection The betel plantation should be selected as a sheltered Pingyang or gentle slope, convenient irrigation, and a lot of lots with good lighting conditions. The soil is deep sandy soil, loose soil, rich in organic matter, and sandy soil with a neutral acidity of soil acidity is better.
4.2 Fine soil preparation: deep plowing in winter, plowing and soil drying, tillage depth 30~40cm, smashing and fine-grained when site preparation, deep sorghum sorghum, deep ploughing and fine hoeing, conditions can deepen the ditch around the field, favorable irrigation to prevent long-term stains water.
4.3 Soil Treatment Before soil preparation, 667m2 of lime 50~100kg was used to disinfect the soil. Pre-planting 667m2 with 5% phoxim granules 1.0kg mixed soil 30kg applied to control earthworms, golden worms, cockroaches and other underground pests, reduce the damage of larvae caused by underground pests caused by wounds caused by soft rot pathogen invasion.
4.4 Rotating betel nuts can be used in rotation with crops such as rice, corn, onion and garlic, and should not be rotated with cruciferous plants, Solanaceae (eg tobacco), and cucurbit crops, and should not be continued for many years. The rotation cycle is generally 2-3. year.
4.4 Selected species should be selected on the bulb port flat, small nest and the whole corm as bulbous or bread-shaped, and navel small, mature, no rupture, no scars, no mold and other characteristics of the species.
4.5 Drying Seeds Before planting seeds, turn the seedlings into the sun for 1 to 2 days. This can be used for germination, germination, and promotion of buds and buds.
4.6 Sterile sterilizers After sunning seeds before sowing, seed dressing or soaking with suitable agents can effectively reduce the occurrence of soft rot in the pre-growth stage. Seed dressing available wood ash: lime (1:1). Seed soaking with 72% of agricultural streptomycin sulfate soluble powder 2500 times, 20% thiazole copper suspension 500 times soaking for 1 hour, remove and dry, and then plant.
4.7 Rational fertilization Apply balanced fertilization and formula fertilization. During the whole growth period of betel nut, pay attention to the application of decomposed organic fertilizer. Basal fertilizer should be applied as much as possible to decompose farmyard manure; chemical fertilizers can be used for topdressing, potassium fertilizer should be reused, and partial nitrogen fertilizer should not be applied. . The 667m2 basal fertilization organic fertilizer 1500~2000kg, 15:15:15 NPK compound fertilizer 50kg, superphosphate 50kg, to deep-applied, uniform application, deep dipping evenly.
4.8 Scientific management of water The betel nut was afraid of lice in the early stage and was afraid of drought in the later stage. In the early growth stage, the soil is kept moist. During the middle and late growth stages, the high-temperature and dry season, the transpiration water consumption is large. Except for the evacuation of the arable water, the water can be kept in the ditch for the rest of the time to prevent the leaves from drying out. If typhoon and stormy weather occur, we must drain the ditch water in time, and the greenhouse cultivation techniques for bitter herbs in the field must also remove stagnant water when the diseased plants are found, reduce the humidity in the field, and spray the pesticide in time.
4.9 Cleaning the garden During the growth of the betel nut, the yellow and old diseased leaves in the field must be removed. If a susceptible plant is found, it should be immediately removed from the field and deeply buried in the field. The lime should be disinfected by applying lime to prevent disease spread. After the betelnuts are harvested, they should also promptly clear the fields.
4.10 At the beginning of disease prevention, the diseased plants should be removed after the emergence of diseased plants in the field. Drainage should be promptly conducted and the pesticide should be sprayed immediately. Changning County should be typhoon-rainstormed frequently from June to September, and should be drained immediately after the typhoon storm and immediately sprayed to protect it. Pharmacy can be used 72% of agricultural streptomycin sulfate soluble powder 2500 times, 20% thiazolone zinc suspension or 20% thiazole copper (Lonke) suspension 500 times, 77% copper hydroxide (kill) 600 times Liquid irrigation or spraying, once every 5 to 7 days, 2 or 3 times in succession, pay attention to alternating use of drugs.
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