Locally known as kamoteng kahoy or balinghoy, cassava (scientific name: Manihot esculenta) ranks second only to sweet potato in hectarage among root crops produced in the country. It is mainly grown for its tubers which are a rich source of carbohydrates. Unknowingly, it is a good source of calcium and ascorbic acid.
However, there are many reasons why Filipino farmers should plant cassava. Let’s start with its food uses, which include confectionaries, native pastries like suman and bibirigka, sago, vegetables, food seasoning, noodles and flour. Although not the staple of Filipinos, cassava feeds about 800 million people around the world, according to the International Center for Tropical Agriculture (CIAT).
Another important product is cassava starch, known in the world trade as tapioca flour. Extracted from the tuber, it is used by a wide variety of industries – food, pharmaceutical, paper, adhesive, textile, mining and other manufacturing industries.
In the food industry alone, the uses for cassava flour are numerous. Studies have shown that cassava flour can substitute for wheat flour in baked products, as much as 10% in bread and can be higher in other baked products. It is utilized as thickener for soups, baby food, sauces and gravies.
Cassava flour is excellent filler that could supplement the solid contents of ice cream. It is also a good binder for sausages and other processed meat products to prevent these from drying up during cooking.
The use of cassava as livestock feed in the country has been investigated. Studies at the University of the Philippines at Los Banos (UPLB) have shown that cassava meal can be used as a substitute for feed grains in compounded animal rations. On the other hand, cassava leaf meal contains 18-20% protein, so that it is a good livestock feed not only for poultry but also for other livestock.
Cassava can also be a good solution to the problems of climate change and fuel shortage. In China, Thailand, and Brazil, cassava is becoming an important biofuel crop. A feasibility study has found that cassava has a very high starch-to-sugar conversion ratio. This high starch content means that a high percentage of sugar can be converted from it, and which, in turn, is needed to produce biofuel.
Cassava can also help control erosion. “Farmers can grow cassava and control – even prevent – hillside erosion by following simple methods,” said Dr. Mabrouke Elsharkawy, CIAT cassava physiologist. This can only be attained if farmers shift their method of farming to minimum or no tillage, “and protect the soil with live, permanent mulch like a forage legume.” He added, “Farmers can also fertilize cassava to make it grow faster, and to cover and protect the soil from rain.
Cassava is an easy-to-grow crop. “The crop grows well on poor soils found on eroded hillsides because it resists adverse conditions such as drought,” Dr. Elsharkawy pointed out. When farmers can’t grow corn or beans in depleted soils, cassava is their only choice.
In the Philippines, cassava is best grown in deep soil with friable structure such as light sandy loams of medium fertility. Top soil should be 30 centimeters in depth. Successful use of almost all soil types is possible, provided that they are not waterlogged, shallow or stony.
There are several varieties of cassava grown in the country. But commercially, the following are highly recommended: Lakan 1 (fresh root yield: 32 tons per hectare), Sultan 6 (39.1 tons per hectare), Sultan 7 (37.9 tons per hectare), Rajah 3 (37 tons per hectare), and Sultan 10 (40 tons per hectare). Sultan 6, Sultan 7, and Sultan 10 are industrial types suitable for starch and feed production. Lakan 1 and Rajah 3 are both all-purpose types appropriate for food, starch, and feed production.
Growing cassava entails simple farm operations such as land preparation, planting, replanting, weeding, fertilization, irrigation, and harvesting. Small scale production requires 51 man-days to operate a hectare of land. The plantation type of production needs 55 man-days per hectare to undertake all the necessary farm operations.
The Philippine Council for Agriculture, Forestry and Natural Resources Research and Development and UPLB’s Institute of Plant Breeding have join together to come up with an information bulletin on cassava production:
The field is plowed and harrowed once when using a tractor. However, when using an animal-drawn implement, the field is harrowed twice. Ridges are constructed at one meter apart. Fifty bags (good for one hectare) of compost or dried animal manure are incorporated to the soil during land preparation.
Cassava stalks as planting materials should be less an eight months old should be free from fisect pests and diseases. These should be cut at 20-25 centimeters long and grouped according to the part of stalk from which they were derived: base, middle, and top (they should also be planted by group). Stalks stored in a cool shaded place can last up to three months. But for better germination, the cuttings should be planted as soon as possible.
Cuttings from the base of the stalk are better planting materials than those from the top in terms of germination, and root and starch yield. The planting materials are planted at a distance of one meter between ridges and 0.75 meter between hills. They can be planted horizontally, vertically (where 3-5 centimeters is left uncovered), or slightly inclined. Horizontally is recommended in relatively dry field, vertically in very wet soil or during rainy season, and slightly-inclined in a soil with near optimum moisture.
During dry season, the cuttings are planted in furrows while on the ridges during rainy season. Missing hills should be replanted two weeks after planting.
Six bags of complete fertilizer (14-14-14) are applied (basal) before planting. The fertilizer is covered with a thin layer of soil. Two months after planting, the crops are side dressed with two bags of urea (46-0-0). The fertilizer is placed in band 15 centimeters away from the base of each plant.
After doing fertilization, the field is immediately irrigated to dissolve the fertilizer. Irrigation is highly recommended thereafter, during the first three months after planting during dry season. During the rainy season, irrigation is needed only when necessary.
During the first two months, weeding is recommended. Off-bar cultivation is required 3-4 weeks after planting followed by hill-up 2-4 weeks later. After the second month of crop establishment, weeding is no longer required. Uprooting or cutting off tall weeds is all needed.
Eight months after planting, partial sampling is advised to determine if the roots are mature enough to be harvested. If they are, the roots are harvested manually if the soil is friable. In slightly hard soil, a bar is used to dig the soil and to serve as lever. Or, an animal-drawn plow may be employed passing at the sides of the plant to break the soil.
If harvesting is done by hand, the stems are cut first, leaving a portion at the base of the plant to serve as handle to pull the storage root up. The storage roots are detached from the stem using a sharp bolo. Soil sticking on the roots is removed using a stick. The harvested tubers must be sold immediately; if not, they must be stored in a shaded place.
According to scientific researches, about 23% of total cassava harvest is lost due to fast deterioration. Bruises and cuts inflicted during harvesting contribute to this deterioration. This problem has sparked many possible solutions like appropriate packaging mediums, controlled conditioned, etc., but none of them has been completely successful.
Cassava is grown mostly in Central Visayas, Bicol, and Central Mindanao. They are also an important crop in Eastern and Western Visayas, Western and Southern Mindanao, and Southern Tagalog.
The Bureau of Agricultural Research said the provinces of Saranggani, South Cotabato, Sultan Kudarat, Misamis Oriental, General Santos City, and Zambales are good sites for cassava production. Potential areas of plantations are Bukidnon, Negros, North Cotabato, and Davao.
source: author: Henrylito D. Tacio, Marid Digest