Group Standards of the People's Republic of China CN / TUANTI
Latest
T/DBNCH 001-2024
Scope
4 Nutrition Quality Evaluation Requirements for Xia Dong Sweet Potato
4.1 Sensory Criteria
Xia Dong sweet potatoes are spindle-shaped, slender, or oval in shape with purple-red skin and vivid color, smooth surface. The flesh is pale yellow to orange red, soft, glutinous, fragrant, fine-textured without fibers, and has a rich aroma.
4.2 Physical and Chemical Criteria
Starch ≥ 15.0%
Soluble sugar ≥ 6.0%
Crude fiber ≥ 0.8%
4.3 Limitation on Contaminants
The limits for contaminants should comply with GB 2762 and relevant national food safety standards.
4.4 Limitation on Pesticide Residues
The limitations on pesticide residues should conform to GB 2763 and relevant national food safety standards.
4.5 Evaluation Criteria
Xia Dong sweet potatoes must meet the nutritional quality, contaminant, and pesticide residue limitation criteria mentioned above, as well as the quantitative limits specified in NY/T 1049 for green industry standards.
5 Cultivation Environment
It is preferable to select locations with adequate sunlight, good drainage conditions, deep soil layers rich in organic matter. The cultivation environment should comply with NY/T 391 regulations.
6 Cultivation Techniques
6.1 Variety
High-quality sweet potato varieties from the designated area.
6.2 Site Conditions
Altitude ≤ 100 m, soil is loamy with abundant organic matter, effective soil layer thickness ≥ 35 cm, and soil pH value between 4.5-6.5.
6.3 Seedling Cultivation
6.3.1 Time and Method for Seedling Cultivation
Adjusted according to the climate conditions of the year.
6.3.2 Construction of the Seedbed
The width is 1.2 m - 1.6 m, length determined by transplanting area, depth 15 cm - 25 cm, bed bottom requires central high and peripheral low, southern side deep and northern shallow, vertical walls to ensure uniform temperature distribution and even seedling emergence.
6.3.3 Selection and Disinfection of Seeds
Healthy, intact, disease-resistant Xia Dong sweet potato tubers are selected as planting materials. Prior to sowing, disinfection with fungicide is carried out using a 50% Dichlorophenylidene 500 times dilution or a 50% Methyl Thiocarbamoyl Amide wettable powder 500 times dilution for 10 minutes.
6.3.4 Planting
Disinfected tubers are planted horizontally at the bottom of the seedbed with spacing of 15 cm - 20 cm, and covered with a layer of fine soil 3 cm - 5 cm thick.
6.3.5 Management of Seedbed
Maintain temperature and humidity in the seedbed before sprouting; after sprouting, provide sufficient water to maintain moist soil as seedlings grow. When the plant height reaches approximately 25 cm, transplant the seedlings. After transplantation, apply appropriate fertilization and irrigation while controlling pests and diseases during the growth period.
6.3.6 Standards for Seedling Selection
Select healthy, robust plants with a stem length of 15 cm - 20 cm, stem diameter of 5 mm - 6 mm, full sap, thick and dark green leaves without disease or pest damage, and short internodes as seedlings.
6.4 Land Preparation and Hilling
Plow depth is 20 cm - 25 cm, row spacing 90 cm - 100 cm, and ridge height 30 cm - 35 cm.
6.5 Transplanting
6.5.1 Time for Transplanting
Determined based on the climate conditions of the year.
6.5.2 Method of Transplanting
Flat or oblique planting can be used; during transplantation, plant the sprouted sweet potato stem horizontally into 3 to 4 nodes deep with an oblique angle.