Potato and Tuber Crops

True Potato Seeds

• Nearly 40% of total production of potato cultivation is for seed tubers.
• Bulky nature of tubers is a problem for transportation and it increases seed cost considerably.
• Transmission of viral diseases through tubers is another disadvantage.
• To avoid above bottle-necks, the concept of true potato seed (TPS) was evolved.
• Inadequate supply of seed tubers at an affordable cost to distant places is overcome by using TPS as planting material.
1. TPS is required only in a small quantity, 100-150 g/ha compared to 1000-1500 kg /ha by tubers.
2. TPS is free from viral diseases and by using TPS, storage loss of seed tubers can be avoided.
3. For production of TPS, parental lines are planted as summer crop in North Indian hills.
4. In plains, extra light for 4-5 hours in the end of the day during December-January by 150 W sodium lamp is provided for flowering.
5. Male parent should flower profusely and should be highly fertile with abundant pollen grains.
6. Female lines should be male sterile.
7. Both male and female parents are planted side by side in the ratio of 1:4 in same block and are artificially pollinated.
8. For both parents, tubers of 30 g weight are planted.
9. After germination, only a single stem plant is retained in female block.
10. Female flowers are pollinated in morning followed by re-pollination next day by applying pollen grains on stigma using a brush.
11. Well developed berries are collected 40-50 days after pollination and allowed to ripe at room temperature for 2-3 weeks.
12. Seeds after extraction are treated with 10% hydrochloric acid with continuous stirring for 20 minutes. Seeds are then washed thoroughly and dried in shade.
13. To break dormancy of freshly extracted seeds, TPS is soaked in GA-3 (2000 ppm) solution for 48 hours.
14. Seeds are later dried in shade and sown in the nursery bed.
15. Seedlings are transplanted to main field at 4-5 leaf stage.
16. Small tubers (40 g size) produced in the seedlings of TPS are also used for planting.
17. In spite of great expectations, the TPS has not become popular due to heterogeneous nature of progenies and practical difficulties in crop raising.
18. This is currently employed for development and exchange of varieties among research institutes