Integrated management for healthy seed production
The various steps involved in the production of certified seed through integrated management of various viral disease are:
1. Identification/selection of a suitable potato variety having resistance to PVY, PLRV and PVX, if possible.
2. Clean-up of the variety if riddled with viruses through meristem-tip culture, theremotherapy and or chemotherapy.
3. Maintenance of the virus-free stocks in vitro as the parent material for use in the production of other categories of seed potatoes.
4. Production of minitubers from parent stocks under in vitro and insect-proof greenhouse conditions.
5. Selection of suitable areas free from various soil-borne diseases.
6. Selection of growing period which is sufficiently long and is free from vector activity.
7. Isolation of the selected area from other solanaceous crops to avoid spread of viruses to seed crop. Removal of ground keepers from previous crop and weeds.
8. Use of granular insecticides in the soil to control sucking insects which may also act as vectors.
9. Fallowing of the area for one season, and crop rotation with non solanaceous crops.
10. Planting the area with virus-free stocks; inspection of the crop and testing of suspected plants for viruses; removal and destruction of virus-infected plants. Wherever possible, virus free minitubers may be planted.
11. Vector appearance may be forecast and necessary control measures adopted. The haulms should be destroyed as soon as the critical level of 20 aphids per 100 compound leaves of 34 plants selected at random is reached.
12. Various cultural operations like weeding and hoeing during crop growth may be avoided to check the spread of contagious viruses. Implements used for the purpose may be disinfected before use.
13. Stop irrigation after haulms destruction and harvest the crop only after sufficient skin curing to avoid bruising damage.
14. Post harvest inspection to ascertain the level of virus(es) due to infection during field exposure of the crop and certification of the seed which meets the prescribed norms for certification.
Certified seed can be used directly for ware crop production or for multiplication as home-grown seed for further use if environmental conditions permit.