ICS 65.020.20         
B 00 
 
 
 
National Standard of the Peop le’s Republic of China  
 
 
GB 18133 —200X 
 
To replace GB18133 -2000 , and partially rep lace GB4406 -1984  
 
 
 
 
 
 
 
 
 
 
Seed Potatoes  
 
 
(for approval)  
 
 
 
 
 
 
 
 
 
 
 
 
 
Promulgated on XX -XX-200X     Implemented on XX -XX-200X  
Promulgated by the General Administration of Quality Supervision, Inspection and 
Quarantine of the People's Republic of China  (AQSIQ ) and Standardization 
Administration of the People's Republic of China (SAC)  
 
GB/T 18133 —200X 
2  
 
Introduction  
 
 
Article 5.2 of this standard is mandatory, and the r est are  recommended.  
This standard is compiled according to the regulations in GB/T1.1 -2009.  
This standard is provided to replac e GB 18133 -2000  Certified Seed P otatoes , and partially  
replace GB4406 -1984  Seed Potato es. The standard  is different from  GB 18133 -2000 Certified 
Seed Potatoes  in the following  aspects : 
− revise s the standard name;  
− increases the normative reference s; 
− revises the t erminolog y and definitions;  
− modifie s the seed potato grading;  
− revise s the field qua lity requirements and test methods;  
− revise s the tuber quality requirements and test methods;  
− increase s the laboratory test; 
− revise s the grading rules;  
− reduce s the transportation content;  
− revise s the label content.  
 
This standard replaces  the seed potato gr ading and seed potato grading index in GB4406 -1984 
Seed Potato es. 
This standard was put forward by  the Ministry of Agriculture of the P eople's Republic of 
China.  
This standard is put under centralized management by  the National Technical Committee for 
the Standardization of Crop Se ed (SAC/TC37).  
The standard was draft ed by : Virus -free Seedling Research Institute of Heilongjiang 
Academy of Agricultural Sciences ( Virus -free Seed Potato Quality Supervision and 
Inspection Centre  of the Ministry  of Agriculture , Harbin),  the Institute of Vegetables and 
Flowers , Chinese Academy of Agricultural Sciences, Keshan Branch of Heilongjiang 
Academy of Agricultural Sciences, Department of Agronomy of Northeast Agricultural 
University, Potato Quality Supervision and Testing Centre  (Zhangjiakou)  of the Ministry of  
Agricultur e, College of Agriculture  of Hunan Agricultural University , Huazhong Agricultural 
University, Root and Tuber Crop Research Institute of Yunnan Normal University , Chin ese 
Academy of Inspection and Qua rantine  and Seed Potato Research and Development Centre  of 
the Great Northern Wilderness.  
This standard was main ly drafte d by: Bai Yanju, Bian Chunsong , Li Xuezhan, Jin Liping, Xie 
Kaiyun, Sheng Wanmin, Chen Yili, Wang Fengyi, Yin Jiang, Xiong Xing yao, Xie Conghu a, 
Li Canhui, Li Mingfu, Qiao Yongjun  and Yu Bin. 
All previous editions of the standard s replaced  by this standard are as follows : 
− GB 18133 -2000;  
− GB 4406 -1984.GB/T 18133 —200X 
3  
 
Seed Potatoes  
 
1. Scope  
This standard provides minimum requirements for the quality index, tes t method and label ling 
for seed potato grading.  
This standard is applicable to the production, inspection, distribution, certification and quality 
supervision of seed potatoes in the People's Republic of China.  
2. Normative references  
The following documen ts are indispens able for the application of this document . For dated 
references, only dated versions are applicable to this document. For undated references, the 
latest versions (including all amendments) are applicable to th is document . 
GB 20464  General d irective for label ling of agricultural seeds  
3. Terminolog y and definitions  
The following term inolog y and definitions are applicable  to this section in GB 18133.  
3.1 Seed potatoes  
Pre-elite, elite, qualified I  and qualified II  following corresponding quali ty requirements in  
this standar d. 
3.2 Pre-elite (G1)  
Pre-elite refers to seed potato that is produced u sing breed ers’ seeds, virus -free seedling s 
obtained through tissue culture or microtuber s under isolated conditions such as  insect proof 
net and greenho use, reaches the requirements  in 5.2 of this standard through quality 
inspection , and is used  to produce elite. 
3.3 Elite (G2)  
Elite refers to  seed potato that is produced in a n isolated environment , reaches the 
requirements in 5.2 of this standard throug h quality inspection , and is used to produce 
qualified I . 
3.4 Qualified I (G3)  
It refers to seed potato that is produced in a relatively isolated environment with elite as the 
seed potato, reaches the requirements in 5.2 of this standard through quality in spection , and is 
used to produce qualified I.  
3.5 Qualified II (G4)  
It refers to seed potato that is produced in a relatively isolated environment with q ualified I as 
the seed potato, reaches the requirements in 5.2 of this standard through quality inspec tion, 
and is used to produce commercial potato.  GB/T 18133 —200X 
4 3.6 Seed potato lot  
The potato plant or tuber with the same origin, the same plot, the same variety, the same grade , 
the same harvest period and practically consistent quality  is taken  as a lot. 
4. Pest 
4.1 Regulated non-quarantine pest  
4.1.1 Virus 
Potato virus X , PVX  
Potato virus Y , PVY  
Potato virus S , PVS  
Potato virus M , PVM  
Potato leafroll virus , PLRV  
4.1.2 Bacteria  
Ralstonia solanacearum  
Erwinia carotovora  subspecies atroseptica , Erwinia carotovora  subs pecies  carotovora , 
Erwinia chrysanthemi  
Streptomyces scabies  
4.1.3  Fungus  
Phytophthora infestans  
Fusarium  sulphureum  
Pythium ultimum  
Rhizoctonia solani  
4.1.4 Insect  
Phthorimaea operculella  
4.2 Quarantine pest  
4.2.1 Virus and viroid  
Potato virus A , PVA  
Potato spindle tuber viroid , PSTVd  
4.2.2 Fungus  
Synchytrium endobioticum  
4.2.3 Bacteria  
Clavibacter michiganensis  subspecies sepedonicus  
4.2.4  Phytoplasma  
Potato witches’ broom phytoplasma  
4.2.5 Insect  
Leptinotarsa decemlineata  GB/T 18133 —200X 
5 5. Quality requirements  
5.1 Se ed potato grading  
Seed potato grad es are divided into the pre -elite, elite, qualified I  and qualified II . 
5.2 Quality requirements for seed potatoes at all levels  
5.2.1 Allowable rate of quarantine pest : The allowable rate of all quarantine pests listed in  4.2 
is "0" in seed potato production , and such diseases and insect pests, once discover ed, should 
be immediately reported to the quarantine department, which takes corresponding measures  
according to the varieties of diseases and insect pest s. At the same  time , all potatoes in this 
plot cannot be used as  seed potato . 
5.2.2 Non-quarantine pes ts and allowable rate of other item s 
Regulated non -quarantine pest and other inspection items of the seed potato at all  grade s 
should comply  with the minimum requiremen ts (See Table 1, Table 2 and Table 3).  
 
Table 1 Field inspection quality requirements for seed potato plants at all grades  
Allowable rate  (%)a 
Items 
(G1) Pre -elite (G2) Elite  (G3) Qualified I  (G4) Qualified II  
Miscellaneous  0 1.0 5.0 5.0 
Severe  mosaic virus  0 0.5 2.0 5.0 
Potato leafroll virus, PLRV  0 0.2 2.0 5.0 Virus 
General  virosis  b 0 1.0 5.0 10.0 
Ralstonia solanacearum  0 0 0.5 1.0 
Erwinia chrysanthemi  0 0.1 0.5 1.0 
a represent s the percentage of positive samples of detect ed items in the total number of detected  samples.  
b represents  all plant s with  viral symptom s. 
Table 2 Quality inspection requirements for harvested seed potatoes at all grades  
Allowable rate  (%) 
Items 
(G1) Pre -elite (G2) Elite  (G3) Qualified I  (G4) Qualified II  
General  virosis (PVY  and PLRV ) 0 1.0 5.0 10.0 
Ralstonia solanacearum  0 0 0.5 1.0 
 
Table 3 Quality requirements for warehouse inspection of tubers of seed potatoes at all 
grades  
Allowable rate (pcs /100 pcs) Allowable ra te (pcs /50kg ) 
Items 
(G1) Pre -elite (G2) Eli te (G3) Qualified I  (G4) Qualified II  
Miscellaneous  0 3 10 10 
Pythium ultimum  0 2 4 4 
Carotovora  0 1 2 2 
Phytophthora infestans  0 2 3 3 
Fusarium  0 3 5 5 GB/T 18133 —200X 
6 Streptomyces scabies  a 2 10 20 25 
Rhizoctonia solani  a 0 10 20 25 
Phthorimaea operculella  0 0 0 0 
External defects  1 5 10 15 
Cold injury  0 1 2 2 
Soil and impurity  b 0 1% 2% 2% 
a means that the scab area does not exceed 1/5 of the tuber surface area.  
b means that the allowable rate is calculated as per the weight percentage.  
 
6. Inspection metho d 
6.1 Field inspection  
6.1.1 Pre-elite production process in spection  
During the 30th to 40th day after cuttage of the seedling  obtained through tissue culture  is 
completed or microtuber emerges  in the g reenhouse or net shed, all plants under the same 
produ ction environmen t are visually observed once, and abnormal plants or organs or tissues 
that are  undiagnosed  through visual observation  must be  sample d immediately  for laboratory 
test. 
6.1.2 Field inspection of the elite, qualified I and qualified II  
At lea st 5 to 10 points for each seed potato lot are randomly inspected using  the visual 
observa tion method with  100 plants at each poin t (See Tab le 4), and abnormal plants or 
organs or tissues that are undiagnosed through visual observation  must be sampled 
imme diately for laboratory test.  
 
Table 4 Number of sampling inspection points per seed potato  lot 
Inspection area  (hm2) Number of inspection points  Check total (plant)  
1 5 500 
>140 6-10 (increase  1 inspection point in the event of increas ing of every 10 hm2) 600-1000  
>40 10 (increase  2 inspection points in the event of increas ing of every 4 0 hm2) >1000  
 
The whole field inspection process is required to be completed within 40 days.  The first 
inspec tion is at the squaring stage  or flowering stage.  The s econd inspec tion is about 30 days 
before harves t. 
If any index in the  first inspection is more than  5 times the allow able rate, then stop inspection , 
and the potato in this plot cannot be sold as seed potato . 
If any index in the first i nspection is not more t han 5 times the allowable rate,  then diseased 
plants and hybrid plants can be uprooted  to lower ing the  rate, and the second inspection res ult 
is the final field inspec tion resul t. GB/T 18133 —200X 
7 6.2 Tuber inspection  
6.2.1  Inspection a fter harvest  
During the harvest and s torage period, s eed potato  is randomly sampled  according to the  
inspection area of seed potato in  the field during harvest , or a certain number  of tubers  are 
random ly sample d from the warehouse for laboratory test. 200 grains of pre -elite out of every 
1000 000 grains of each variety  are inspected  (40 grains are increased in the event of 
increas ing every 1 million  grains, and less than 1  million  grains are calculated as per  1 million  
grains). The number of samples to be inspected is determined according to  the production area 
of each seed potato lot in the field (See Ta ble 5).  
Tuber  treatment:  The tuber is planted by breaking the dormancy, and the seedling is inspected 
since it is about 15 cm  high.  The virus is detected  using enzyme -linked immunosorbent assay  
(ELISA) or reverse transcriptase polymerase chain reaction (RT -PCR) method, viroid is 
detected  using the R -PAGE, RT -PCR or nucleic acid spot hybridization (NASH) method, and 
bacteri um is  detected using ELISA or polymerase chain reaction (PCR) metho d. The a bove 
disease s can also  be detect ed using the test technology  with higher sensitivity than 
recommended metho ds. 
 
Table 5 Number of harvested samples for laboratory test  
Seed potato grading  40 hm2* number  of samples (pcs)  
(G2) Elite  200  ( increase  40 tubers in the event of increas ing of every 10 -40 hm2)  
(G3) Qualified I  100  ( increase  20 tubers in the event of increas ing of every 10 -40 hm2)  
(G4) Qualified II  100 ( increase  10 tubers in the  event of increas ing of every 10 -40 hm2)  
*  Area unit of the seed potato   (hm2) 
 
6.2.2 Warehouse inspection  
Seed potato is inspected before leaving the warehouse.  
The number of sampling points for pre -elite is determined according to  the output  of each lot 
(See Ta ble 6), and 500 grains of tubers are random ly sampl ed at  each poin t. 
The number of sampling points for s eed potatoes at all grades in the field is determined 
according to the total output of each lot (See Ta ble 7), 25 kg of representative samples  should 
be randomly taken at each  point, and inspec tion results of the samples represent the sampl ed 
lot. Seed potato of the same lot stored in  different warehouses  is treated as per  different lots 
with the indication of quality traceability.  
 
Table 6 Numb er of t uber sampl es of the pre -elite 
Total output of each lot (10000 grains)  Number of sampling points of tuber  (pcs) Number of inspected samples ( grains ) 
50 5 2500 
>50500 5-20   ( increase  1 inspection point in the event of increas ing of 
every 300000 grains)  2500 -10000  
>500 20  (increase  2 inspection points in the event of increas ing of 
every 1 million grains)  >10000  
 
Table 7 Number of tuber samples of seed potatoes at all grades in the field  
Total output of each lot ( t) Number of sampling points of tuber  (pcs) Amount of inspected samples (kg)  
40 4 100 GB/T 18133 —200X 
8 >401000  5-10  (increase  1 inspection point in the event of 
increas ing of every 200 t)  125-250 
>1000 10   (increase  2 inspection points in the event of increas ing 
of every 1000 t)  >250 
 
Visual observa tion is used , and laboratory test technique may also be used for the diseases 
that cannot be diagnosed through  visual observa tion. Visual observa tion incl udes the 
inspection  of not only tuber epidermis, but also a certain  amount of internal  symptoms , when 
necessary . 
7. Decision rules  
7.1 Grading 
The grading standard means that the grade and generation number of s eed potato satisfy  the 
minimum qual ity requirements of field inspec tion and inspection after harvest.  
7.2 Relegation  
If any test  paramete r fails to reach quality requirements of the seed potato grade to be 
produce d, the seed potato is r educed to  the quality grade corresponding to the inspec tion 
result . If the potato fails to reach the seed potato quality index  of the lowest grade , it cannot 
be used as seed  potato . 
If the second field inspec tion is more than the  allowable rate of  seed potato  of the lowest 
grade , the potato in this plot  cannot  be used as seed potato.  
7.3 Standard  for leaving the warehouse  
Before leaving the warehouse, a ny grade  of the seed potato s hould achieve th e tuber quality  
requirements  through warehouse inspection. If resel ected seed potato or seed potato reduced 
to the q uality grade corresponding t o the warehouse inspection  result s fails to reach  the seed 
potato quality index of the lowest grade , it is necessary  to reselect the seed potato before 
delivery until  reaching  the standard . 
8. Label ling 
Relevant regulations of G B 20464  General Directive for Labelling of Agricultural Seeds  are 
implement ed for label ling.