Seed Standards

A. Standards for mini-tuber (G-0) production in the aeroponics/ nethouse facility (1) General requirements (i) Isolation: Minimum 1 meter between the different varieties grown in net house, so as to avoid mechanical admixture. In aeroponics facility separate grow boxes shall be used for each variety and two varieties cannot be grown in the same grow box. (ii) All micro propagation and aeroponics or nethouse facilities must be approved by competent authority set up by the state Govt., as per the standards given above under eligibility requirements. (2) Specific requirements Maximum permissible limits Factor Maximum permissible limit *Off type 0.001% *Plants showing symptoms of mild mosaic 0.001% *Plants showing symptoms of severe mosaic, leaf roll, PACLV, GBNV, phytoplasma and apical leaf curl Nil **Plants infected with brown rot (Ralstonia solanacearum) Nil * At the time of crop termination **Maximum permitted at final inspection in the net house raised crop (3) Seed Standards for mini-tuber Factor Permissible limit Weight of minituber (minimum) 1.0 g (minimum) Germination (minimum) 90% (minimum) Varietal purity (percent plants) 99% (minimum) Virus infestation (percent plants) 0.001% (maximum) B. Field standards for G1 to G4 Crop raised out of Potato Tissue Culture based mini-tuber. (1) General requirements Isolation: The fields of seed potato shall be isolated from the contaminants shown in column 1 of the Table below by the distances specified in columns 2-6 of the said Table Containments Minimum distance (meters) G1 G2 G3 G4 Fields of other varieties 5 5 5 5 Fields of same variety not conforming to requirement for certification 5 5 5 5 (2) Specific requirements Factor Maximum Permissible limits G1 G2 G3 G4 Off types (%)(1st and 2nd inspection) 0% 0% 0.05% 0.05% Plants showing symptoms of mild mosaic (1st and 2nd inspection) 0% 0% 1.0% 2.0% Plants showing symptoms of severe mosaic, leaf roll, PACLV, GBNV, phytoplasma (1st and 2nd inspection) 0% 0% 0.5% 0.75% *Total virus 0% 0% 1.0% 2.0% Plants infected by brown rot (syn Bacterial wilt) Ralstonia solanacearum (1st and 2nd inspection) None None None None **Regrowth of plants after destruction of haulms (4th inspection) 0% 0% 0.5% 0.5% *Of the two inspections, the higher virus percentage will be considered for the purpose of the specified limits of tolerance. **Standards for re-growth after destruction of haulms shall be met at fourth inspection to be conducted about 10 days after haulms cutting. Note: (i) All off types and diseased plants should be rouged out along with the tubers and destroyed. (ii) Gaps in the seed plot should not be more than 10.0%. (iii) Haulms must be destroyed as close to the ground as possible before the date specified by the Certification Agency. Failure to destroy haulms in time shall render the crop liable for rejection. C. Seed Standards (G1 to G4) (1) Size and weight Specification Size Mean length and two widths at the middle of tuber Corresponding weight Seed Size 30-55 mm 25-125 g Large size Above 55 mm Above 125 g Note: (i) The size of tuber will be decided either on the basis of mean of two widths of a tuber at the middle and that of length or on the basis of corresponding weight of tuber. (ii) In a seed lot, tubers not conforming to specific size of seed shall not exceed more than 5.0% (by number). (iii) The seed material shall be reasonably clean, healthy, firm and shall conform to the characteristics of the variety. The tubers not conforming to the varietal characteristics shall not exceed 0.050% for G1 and G2 class of seed and 0.10% (by number) for G3, G4 and G4 class of seed. (iv) Cut, bruised, unshapy, cracked tubers or those damaged by insects, slugs or worms shall not exceed more than 1.0% (by weight). (v) Greenish pigmentation on tubers will not be a disqualification for certification. (2) Maximum tolerance limit of tubers showing visible symptoms caused by the diseases mentioned below will be as follows: Disease Maximum Permissible limits (By number) G1 G2 G3 G4 Late blight (Phytophthora infestations (Mont.) de Bary), dry rot (Fusarium caeruleum (Lib.) Sacc.) or Charcoal rot (Macrophomina phaseoli (Tassi) G. Goidanich). 0.1% 0.1% 0.5% 1.0% Wet rot (Scierotium rolfsii) Sacc.) None None None None *Common scab (Streptomyces scabies (Thaxt) Waks. & Henrici) 1.0% 1.0% 2.0% 3.0% Brown rot (Ralstonia solanacearum (E.F. Sm.) E.F. Sm.) 0.0 0.0 0.0 0.0 **Black scurf (Rhizoctonia solani Kuehn.) 2.0% 3.0% 5.0% 5.0% Total diseases 3.1% 4.1% 7.5% 9.0% *Even if a single tuber infected with common scab is detected in a seed lot, the entire seed lot shall be treated with approved chemical before seed lot is declared fit for certification. Seed lots having infected tubers more than the prescribed limits will not be certified even after treatment. **(i) A tuber carrying 5% or above scuffed surface will be considered as one infected unit. (ii) Seed lots having black scurf infection more than the prescribed limits (5-10%) could be certified after treatment with approved chemical/fungicide. (iii) For all diseases, the higher disease percentage will be considered for the purpose of the specified limits of tolerance.