Sweet potato, scientific name: Sweet potato is also called sweet potato, red taro, sweet potato, sweet potato, sweet potato, sweet potato (north), sweet potato (local languages), sweet potato, sweet potato, pillow taro, bamboo taro, sweet potato, fennel sweet potato, red-skinned sweet potato and sweet potato.
Sweet potato belongs to the family Convolvulaceae of the genus Panicum, which is more than 2 meters long and lies on the ground. Its leaves are usually wide oval, 4- 13 cm long and 3- 13 cm wide. Corolla pink, white, lavender or purple, bell-shaped or funnel-shaped, 3-4 cm long, and capsule ovoid or oblate.
cultivation techniques
Seedling raising method
Sweet potatoes should be nursed back to health two months before transplanting, that is, spring potatoes should be nursed back to health in late June, autumn potatoes should be nursed back to health in late June and winter potatoes should be nursed back to health in early August. One-time seedling raising or staged propagation can be adopted.
Seed selection, seedling raising, purification and rejuvenation are conducted every year. Seed selection should be carried out in the same variety field in virus-free and scab-free areas. Medium-sized seed potatoes should be selected as seeds, which are long, uniform in shape, without furrow, flat in epidermis, spots and scars of diseases and insect pests. Before planting, soak in 1.0% copper sulfate solution or 2% sodium hydroxide solution for 5~ 10min, or use organisms permitted by organic production such as Bt and Beauveria bassiana.
Sufficient base fertilizer should be applied to the seedbed. Generally, 500~ 1000kg of self-retting organic fertilizer and 50kg of mineral potassium-magnesium fertilizer are applied every 667 square meters. Sterilize the seedbed with sulfur mixture or lime before planting.
Fertilizer and water management
The demand of sweet potato for nitrogen, phosphorus and potassium varies with different growth stages. Trace nitrogen fertilizer is absorbed more during stem and leaf growth, but less during root expansion; Trim phosphate fertilizer is less absorbed in the middle stage of stem and leaf growth and more absorbed in the stage of root expansion; However, from planting to harvesting, the absorption of potassium fertilizer is more than that of nitrogen and phosphorus, especially in the period of root swelling. Therefore, sweet potato fertilization should be carried out around this feature, with n ∶ p ∶ k = 5 ∶ 6 ∶ 20. It is best to use soil testing and formula fertilization technology.
It is forbidden to use any chemical fertilizer in organic cultivation of sweet potato, and the base fertilizer is the main one. Generally, the amount of base fertilizer accounts for 60%~80% of the total fertilizer application, and the base fertilizer is combined with ridging.
After the transplanted seedlings survived, biogas slurry or fully decomposed dilute manure water was used as seedling fertilizer for 65438 0 times. For the second time, apply 1 times potato-promoting fertilizer at the sweet potato fruiting stage, that is, about 60 days after spring and autumn sowing and about 70 days after winter sowing. Potash fertilizer is the main fertilizer to promote potato growth. Generally, 500 kilograms of self-made organic fertilizer (or organic certified organic fertilizer), 250 kilograms of plant ash or 25 kilograms of mineral potassium magnesium fertilizer are applied every 667 square meters. The general application method is to break the ridge on both sides with a plow, or to make a small ditch on the waist of the ridge with a small hoe, and then mix the fertilizer and probiotics evenly for belt application. After application, it should be watered 1 time to promote its fertilizer efficiency as soon as possible. At the same time, after fertilization, it can also be combined with manual weeding to cultivate the soil.
When planting sweet potatoes, after watering with fixed seedling water, branches and vines began to drag 30 ~ 40 days after planting, and the water demand increased. At this time, in case of drought, it is necessary to water in time, and furrow irrigation can be used, but the irrigation amount cannot exceed the ridge height of 1/2. Generally speaking, it is appropriate to master the basic moisture of soil in water management. In case of rainy days, drainage should be done in time to prevent the accumulation of water from causing potato seedlings to grow white, and the phenomenon that only firewood roots grow and potatoes do not grow.