GB 4406-1984 Seed Potato GB4406-1984 Standard Download decompression password: www.bzxz.net

Scope of application
National Standard of the People's Republic of China
Seed yams.
UDC 635.21/.22
GB4406—84
This standard applies to seed potatoes for commercial operation, and also applies to seed potatoes propagated according to plan by state-owned original (improved) seed farms, farms, townships (teams, households), special breeding areas, seed potatoes for production units for their own use, and variety seed potatoes bred and approved by scientific research and teaching breeding units and individuals. 2 Terms and terms
Original seeds -
refers to seeds of new varieties bred by breeding units (individuals) and approved, and seeds of promoted varieties that have reached the original seed quality standards after purification and rejuvenation.
3 Seed quality grading
Seed potato grading is based on variety purity, tuber uniformity and imperfect tuber rate, among which variety purity is the main grading standard. If either one of the two items of tuber uniformity and imperfect tuber rate is one level lower than the variety purity level, or either one or both of them are higher than the variety purity level, the grade shall be determined according to the variety purity level. If either one of the two items of tuber uniformity and imperfect tuber rate is one level lower than the variety purity level, or one of the two items is at the same level as the variety purity level and the other is two levels lower than the variety purity level, the grade shall be reduced by one level according to the variety purity level. If either one of the two items of tuber uniformity and imperfect tuber rate is two levels lower than the variety purity level, the grade shall be reduced by two levels according to the variety purity level, but both items shall not be lower than the lowest standard. Grade index for quality of potatoes
First-grade quality
Second-grade quality
Third-grade quality
Purity not less than,
Tuber uniformity
Not less than,%
Imperfect tubers
Not higher than,%
Note: Tuber uniformity of potatoes and sweet potatoes refers to the percentage of tubers weighing 50-200g for potatoes and 100-250g for sweet potatoes in the total number. Imperfect tubers refer to the percentage of tubers with mechanical damage, insect bites, natural cracks or serious deformities in the total number of tubers. Issued by the State Bureau of Standards on May 21, 1984bzxZ.net
Implemented on January 1, 1985
GB4406-84
Appendix A
(Supplement)
A1 The classification of other seed potatoes not included in this standard shall be determined by each province (autonomous region).
2 Non-quarantine pests and diseases shall be restricted by each province (municipality, autonomous region) according to specific circumstances. A.2
Additional Notes:
This standard was proposed by the Ministry of Agriculture, Animal Husbandry and Fisheries of the People's Republic of China. This standard was drafted by the National Seed Center and the seed companies of relevant provinces (municipalities). 108
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