White potato (Solarium tuberosum L.) ranks fourth among the world’s major food crops and is the staple food of almost half of the world’s population. Apparently, potato by-products is gaining much importance due to their high nutritive value and variety of uses.
Potato production in 2006 was 69,461 tons (t) from 5,451 hectares (ha), with Benguet accounting for more than 60% of the total production. The other major producers are Davao del Sur, Mt Province, and Bukidnon. As production falls short of demand, especially in the processing types, the country imported US$36.4 million worth of potato products in 2006.
Uses and Nutritional Value
Table potato is an ingredient in many dishes and salads. Processing types are made into chips, fries, and flour. It is basically fat free, cholesterol free, and low in calories. It is also a great antioxidant. Most of the vitamins in potatoes are located just below its skin.
Per 100 grams (g) of edible portion, table potato contains:
- Water (g): 79.9
- Energy (kcal): 78.0
- Protein (g): 2.4
- Carbohydrates (g): 16.8
- Calcium (mg): 36.0
- Phosphorus (mg): 49.0
- Iron (mg): 1.1
- Thiamine (mg): 0.12
- Riboflavin (mg): 0.06
- Niacin (mg): 2.2
- Ascorbic acid (mg): 31.0
The most commonly grown varieties of table potatoes are Conchita, Cosima, Granola, Greta, Red Pontiac, Solibao (BSU P03), Franze, and Asterix. The best processing varieties are Atlantic, Diamant, Fina, Igorota (BSU P04), Kennebec, Montahosa, and Raja.
Potato is usually cultivated by planting tubers. Purity of the cultivars and healthy seed tubers are the primary requirements for a successful crop. However, seed tuber is the costliest input in potato cultivation. The tuber seed should be disease free, well sprouted, 30-40 g each in weight, and at the right physiological age (2-3 months from harvest). Seed requirement per hectare is 1,200-2,000 kg.
To overcome the problem on costs and diseases in seed tubers, True Potato Seed (TPS) can also be used as planting material. TPS is a botanical seed developed as a result of fertilization. Most of the diseases transmissible through seed tubers are not passed through TPS. In addition, only about 200 g/ha of TPS is needed, thereby saving cost of transporting bulky plant materials and huge quantities of food material for table purposes. The TPS seedlings are grown to maturity in nursery beds to obtain seedling tubers. These seedling tubers are used as seedpieces for growing a normal potato crop the following season.
Soil and Climate Requirements
White potato can be grown in almost any type of soil except saline and alkaline soils. The most preferred are loose soils, which offer least resistance to the enlargement of the tubers. Loamy and sandy loam soils high in organic matter with good drainage and aeration are most suitable for cultivation. The soil pH range of 5.2-6.4 is ideal. Although a temperate crop, potato can also be grown in a wide range of climatic conditions depending on the variety. It grows best in moderately cool temperatures during the growing season. The vegetative growth of the plant is best at temperatures of 20°-24°C while tuber development is favored at 20°C.
In areas such as Benguet and Bukidnon, March-April and October-November are the best planting time. In lowlands, the best time to plant is from November to mid-December.
Prepare the land thoroughly by plowing and harrowing twice to obtain a friable soil suitable for tuber development. In acidic soils, apply lime 30 days before planting.
Planting can be done using the single-row and the double-row method.
Single-row is suitable for flat areas. It is practiced in Davao del Sur and Bukidnon. Using a carabao-drawn plow, set furrows 75 cm apart and holes 30 cm apart along the furrow.
The double-row method is appropriate for sloping areas. It is practiced in Benguet. Prepare manually 1-m wide raised beds 50 cm apart. Establish 2 rows within the bed spaced 30 cm apart. The distance between holes along the furrow is 30 cm.
For both planting methods, the total plant population per hectare is 44,444. Apply fertilizer in holes, add chicken manure, and cover with a thin layer of soil. Place the tuber over the thin layer of soil and cover with 5 cm thick soil.