Diseases should be strictly prevented in the introduction of sweet potato

At present, the cultivation of sweet potato in our province is expanding to non-traditional planting areas, where the storage and conservation technology of sweet potato does not pass, and when it comes out of the cellar in spring, the seed potato supply can not be guaranteed, and some potato farmers have to introduce varieties from other places to increase the cost. Due to the lack of knowledge about the introduction of potato farmers, diseased potato species are often introduced, resulting in the prevalence of diseases and insect pests. Many diseases and insect pests of sweet potato are spread by potato pieces, and introduction has become the main way to spread diseases and insect pests. The main diseases and insect pests transmitted by seed potato are root rot, black spot, stem nematode, sweet potato ant weevil and so on. In recent years, sweet potato stem nematode disease is prevalent in a large area and root rot is also harmful in some areas due to blind introduction from disease areas in northern Jiangsu.

Stem nematode disease is also called bran heart disease. After the potato block is infected, the inside bran heart and cortex are intact, and the appearance is the same as that of good potato, but it has no use value. It is difficult to eradicate the soil disease caused by stem nematode disease and root rot disease, and the disease will accumulate year by year, seriously affecting the production of sweet potato. Therefore, the first thing to pay attention to in the introduction of sweet potato is not to introduce diseased potato, but also to pay attention to the different uses of sweet potato and the adaptability of sweet potato varieties.

1. Do not introduce species from the ward. At present, sweet potato diseases in northern potato areas are mainly stem nematode disease and root rot disease. These two kinds of diseases will reduce the yield of sweet potato in varying degrees, and even lose yield in serious cases. First of all, the introduction site should be investigated to confirm that there are no diseases before introduction, so as to avoid the introduction of diseased potato.

2. Introduction according to the use. Sweet potato types can be divided into starch processing type, edible baking type and so on. Among them, starch processing type requires that the dry matter rate of varieties should not be too low, the dry matter rate of general starch varieties is more than 28%, and the meat color is white or light yellow. Edible baked varieties require that the potato meat be yellow or orange, and the dry matter rate can be relaxed appropriately.

3. Pay attention to variety adaptability. Sweet potato varieties have special adaptability to soil quality, cultivation mode, climate and other factors, so they can be planted on the basis of demonstration experiments, and should not be introduced in large quantities blindly.