Due to years of vegetative propagation, sweet potatoes are affected by a variety of viral diseases, causing degradation of the species. Seriously affect the yield and quality. Detoxification plants were obtained by inducing the sweet potato microstem tip. The virus-free sweet potato has different physiological habits because it does not carry the virus, and its obvious manifestation is the strong growth potential of stems and leaves, the rapid expansion of the bulk leather, and the increase in yield by 50%. Sweet potato tubers were grown by virus-free culture and transplanted after 30 days of culture. During transplanting, 40% carbendazim should be used to wash the roots 2-3 times, and then transplanted into the field with pest control facilities to produce them. Sweet potato virus-free original species of a species of production. Choose about 0.5 kg of virus-free sweet potato seed and soak it with 40% carbendazim for 20 minutes. It is then placed in a nursery pond that has a geothermal line and covers about 10 cm of horse dung or wheat clothing. With 40% carbendazim water, covered with a plastic film above, to the hotline and maintain about 30 °C for a week, then dropped to 20-25 °C. Generally about 150 seedlings per kilogram can be emerged. Second, the soil fertigation The growth of tubers of sweet potato needs to loose the deep, breathable and moist soil layer. Therefore, it is necessary to properly perform deep plowing. The upper layer of living soil is generally required to be about 30 cm. The selected land should be fertile and fertile. The soil is deep and sandy loam without soil pests is appropriate. Generally, 2000 kg of farmland manure should be applied in Mushi and phosphorus and potassium fertilizers should be added. Due to the strong growth potential of the detoxified sweet potato, nitrogen fertilizer should be reduced. Generally N:P:K is applied at a ratio of 1:0.7:2.5, and Urea has 10 kg of urea, 50 kg of superphosphate, and 40 kg of potassium sulfate. In order to prevent soil stem nematode disease and underground pests, mu dacarbide 10 kg, film ridging cultivation can effectively increase sweet potato yield, generally ridge height 25 cm. Third, choose a strong head lice virus-free sweet potato seedlings planted, spring potatoes should be planted from April 25 to May 5, the density of 3500-4000 strains / acre, pouring good seedling water, summer broadcast on June 1 Planted between -10, density 4000-5000 strains / acre, generally should be planted in the afternoon as well. Fourth, field management Mushrooms should be promptly filled to ensure full seedlings. Virus-free sweet potato grows strong on the ground. If there is no drought, the seedlings generally do not water, in order to increase the temperature and promote root growth. In order to increase the temperature, promote root growth. In July-August, 1-2 times of water should be poured into the water, and the water should be cultivated and weeded in time to keep the soil loose. The secondary roots of sweet potato are vigorous. Therefore, the pods should be smashed in time. Generally, the pods should not be turned over. Wang, combined with spraying ethephon, the concentration of 100-150g / mu, or about 80 grams of paclobutrazol is appropriate to prevent leggy. V. Pest Control Generally from July to October, aphids and weevil insects bite sweet potato leaves is one of the main ways of sweet potato virus transmission. Generally, it uses omethoate and can be sprayed once every 10 days. Alloy Steel Co2 Fire Extinguisher Alloy Steel Co2 Fire Extinguisher,Alloy Steel Fire Extinguisher,Co2 Alloy Steel Fire Extinguisher,Carbon Dioxide Fire Extinguisher JIANGSU NEW FIRE FIGHTING TECHNOLOGY CO.,LTD , https://www.newayfire.com