Cultivation of Potato (Solatium tuberosumlj)
The Potato (Solanum tuberoswn L.) belongs to the family Solanaceae. There are many related species, but only the potato and a few others bear tubers.
Potatoes are an important staple food crop. Annual world production of potatoes surpasses that of all other vegetables and ranks with wheat and rice. Introduced into Europe in the 16th century by Spanish explorers, it is cultivated throughout the world including the Indo-Pakistan subcontinent. Potatoes are used alone and mixed with meat, fish, chicken, and vegetables, & in big cities and towns, potato chips are prepared and sold commercially. The potato is rich in starch and contains protein, minerals, & a fair amount of vitamins, particularly Vitamin – C.
The potato has a wide range of seasonal adaptability. It is a cool season crop and is moderately frost – tolerant Temperature during the growing season has long been recognized as one of the most important factors influencing yield. Young plants grow best at a temperature of 240C; later growth is favored at 180C. Tuber production reaches a maximum at 200C, decreases with rise in temperature, and at about 300C tuber production stops entirely. Short days are beneficial for tuber production.
The potato develops best on deep, fertile, sandy lo clay loams with good water retention capacity. Because the potato has a relatively weak, shallow root system, impermeable layers in the soil limit rooting depth, which restricts water availability to the plant in dry. periods. Thus soil compaction can greatly reduce potato yields. Aeration of the soil has a great effect on the set and development of tubers.
Manures and Fertilizers:
Potato has a high nutrient requirement; a yield of 25 tones of tubers/ha depletes the soil of 119 kg of N, 50 kg of P and 225 kg of K. In light soils and places where organic manures are not easily available, green manuring is beneficial. Well rotted FYM at 30 t/ha should be incorporated into the soil three to four weeks before planting. Research on fertilizer requirements conducted in the Punjab and Sindh suggests that 100 kg N, 80-100 kg of P2O5, and 50 kg K2O per hectare are sufficient- to obtain good yields.
Li hilly areas, potatoes are spaced at 60 x 30 cm and the tubers are planted in furrows. In the plains, however, they are planted on ridges spaced 30 cm apart; the distance between ridges is kept at 45-60 cm.
Potatoes are propagated by tubers, planted either whole or cut into pieces. To obtain maximum yields, healthy, disease-free tubers, free from mixture of other varieties, should he use. Seed rate depends on tuber size; 800-1000 kg/ha is generally recommended. Choudhary et al (1990) conducted a trial comparing improved seed of the Swat and Kaghan varieties brought from the Kaiam Integrated Development Project with seed from the local market. Potatoes grown from the improved seed gave better soil coverage, had a lower incidence of virus attack and higher tuber weight and gave higher yields than those from the locally purchased unimproved seed.
Potatoes need frequent irrigation. The first irrigation should be given immediately after sowing, and thereafter at one week intervals. After tuber formation, the frequency of irrigation is decreased. Care must be taken while irrigating that the water does not reach fee top of the ridge.
Irrigation should be stopped a few days before harvesting.
The size of the tuber increases until the vines become dry. In developed countries, potatoes are harvested by mechanical harvesters. In Pakistan, they are manually harvested by digging up the ridges with a spade. Care must be taken that tubers are not injured during the process. After harvesting, the crop should be kept in the shade.
The average yield of potato is 20-25 tonnes/ha, however it depends upon the variety, cultural practices, and location.