PLANTING RUBBER*

* This is the culture of rubber MP publishes for the benefits of farmers who wish to plant rubber crop. This article is published in the Agricultural and Industrial Life Magazine, November 1955 issue.

Local Names – Para rubber: Goma, Spanish, Filipino. Area and Production – in 1952, the Philippines produced 1,612,000 kilos of crude rubber, the leading producing province being Basilan Island, Zamboanga, Cotabato and Davao.

Trade – the Philippines exported about 200,000 kilos of crude rubber in 1953. The value of rubber and its manufactures, including tires, imported in the same year was P27 million and P32 million in 1954.

Varieties and Yields – the different kinds of rubber under cultivation are not varieties but species, the most important being CERA, CASTILLOA and PARA. Fortunately, PARA, the best of the species is adapted to Philippine conditions. It gives a yield of about 1.06 kilos per tree. In Malaya and Sumatra (Malaysia), the original average yield of 400 – 500 pounds per acre was doubled or raised to 1,000 pounds through rigid selection and bud grafting. More recently, however, through hybridization, there are now plantations – one of them owned by Goodyear in Sumatra – producing an average of 3,000 pounds per acre or roughly 3,000 kilos per hectare. To produce such very high yield, it is most probable that the parent stocks are first filial generation hybrids.

Culture – Para rubber is propagated by seeds, cuttings, and marcotting, budding or grafting. Seedlings are set out in the field when they are 6 to 12 months old. Older seedlings may be planted only after topping. Seeds should be planted closely in seed beds and partly covered with soil and wet gunny sack or straw to preserve moisture until they have germinated. The seedbeds should be undershade, or partially shaded. The seeds germinate within 8 to 15 days. The seeds that have completely germinated should be planted at a distance of 4.47 by 4.41 meters then thinned to 9.14 by 9.14 meters when the trees are 6 years old. The selected seedlings may be planted 6.10 by 6.10 meters apart. Cultivation can be accomplished by plowing between the trees. Cover crops like patani (Phaseolus lunatus), Palawan beans (Phaseolus cakaratus) and others can be planted between rows.

Tapping (Harvesting)

Tapping should be carefully done so that, while the maximum quantity of latex is obtained, there shall be a minimum amount of damage done to the trees. Tapping may be done when a tree has produced a girth of 20 to 24 inches, 3 feet from the ground, or when about 4 to 5 years old growing under normal conditions. Tappings is done by downward cut, but should not be one deeper than the cambium layer, at about 3 feet from the ground. For each tree, a collecting cup of about 150 to 200 cubic centimeters capacity should be provided.

Commercial rubber is produced by coagulating the latex by adding some acid, usually acetic acid. As a rule, one part of the acid to 20 parts of water is used. Of this solution, it requires one liter to coagulate fifty liters or diluted latex. The coagulum passed out through a creping machine, then dried under shade. It generally takes about 20 days to make crepe rubber by this process.

In small plantation, the latex may be prepared for the market by coagulating it in the manner described, and then pressing the coagulum by means of rolling pins, wooden rollers or bottles to get out the water and finally kept under shade until thoroughly dried.

Important Diseases and Insect Pests and Their Control – some of the important diseases of rubber are: fome’s root diseases, brown root diseases, red root diseases, die black, black thread, and brown bast. These can be controlled by cutting off the affected lateral roots as well as top roots, digging out and burning all dead stumps or rotting logs, liming patches, ventilating, covering tapped surface, and coating diseases spots, with antiseptics.

Some of the pests are the rootgrubs which can be repelled with woodashes and scale insects which can be controlled with kerosene emulsion.

Uses – rubber is used for the manufacture of vehicle tires, rubber shoes, shoe sole and heels, miscellaneous rubber toys, as an insulator and in general vulcanization work.

Important Data:

1. Seed rate – 448 seedlings to a hectare

2. Tapping age – 4 to 5 years old

3. Fertilizer require-ments. 400 to 800 kilos per hectare of a mixture containing 6 percent Nitrogen, 6 percent Phospheric acid and 12 percent Potash. Better if soil is analyzed and have fertilizer requirement recommendation.

4. Nature of plant – a tree with abundant milky sap, nearly glabrous and reaching a height of 20 meters; leaflets, 10.20 centimeters long; penicles, pyramidal. /MP