TUNG OIL

Evening Post, Volume CVIII, Issue 139, 9 December 1929, Page 13

TUNG OIL

VITAL TO VARNISH

ACCLIMATISING TREES

DOMINION TEIALS

Tung oil, to quite a large number of people, is probably practically an unknown quantity, but it is a vegetable oil, extracted from the nuts of a certain kind of f/se, and is of vital importance to those engaged in the paint and varnish trade. Tung oil is an essential constituent of certain types of varnish, especially . thoso of the water-resisting kind. During the war it was in very great demand for use iv varnishes for aeroplane wings, and this is still one of its major uses.

Until comparatively recently the only source from which tung oil could be obtained was China. The tree grows naturally there, and the Chinese, by primitive methods which their ancestors have used for generations, extract the oil fixlLi the nuts. But the disturbed conditions existing in China and the unwillingness of the Chinese to apply modern methods of production have combined: to make supplies from China irregular/and supplies from that quarter show no signs -of meeting the increasing, demand. After the war the United States, began to develop its own supply of tung oil. With characteristic thoroughness the idea was carried out as a trade proposition, and tung trees were planted extensively in Florida. Intensive cultivation was adopted, special machinery was devised and erected for extracting the oil from the nuts.. and everything points to the United States in the near future being able to supply to her own varnish makers all the tung oil they require. s

At the same time Great Britain started to move in the matter. Some little time ago the Imperial Institute elected a sub-committee to deal -with tung oil. On the recommendation of this committee, the Empire Marketing Board has approved a grant to the Royal Botanic Gardens at Kew for the distribution of seeds of the tree to various parts of the Empire. A further grant, too, has been made for research into the technical properties of tung oil. Problems dealing with the best methods of extraction of the oil from, the nuts will be investigated; new uses for the oil will be inquired into, and tests will be made as to the possibility of using the residue, after extraction of the essential oil, as a feeding cake.

EXPERIMENTS IN DOMINION.

The tung oil industry may well become in time an Empire industry. With this end in. view Kew has distributed seed to various Empire countries, and promising trials are now in hand iv quite a number of places. New Zealand's Department of Agriculture was alive several years ago to the possibilities of growing tung trees in the Isolated specimens in the xorthern districts undoubtedly flourished, and there seemed to be every prospect p£ being able to grow successful plantations. But the great difficulty was to get seed for experimental purposes. The Chinese growers, .scenting the loss of their market, would not part with it at any price. But where there is a will there is a way, and finally tho Department obtained sufficient seed to make an experimental plantation at To Kauwhata. Towards tho end of last autumn about a thousand plants were put in, and, as far as can be judged at present, these are doing very well.

The fact that the rung tree will grow in New Zealand is no sure foundation for limitless optimism that it will bo a commercial proposition. There are numerous species of tung trees, and the seedlings very greatly in value. Selection and vegetative propagation will have to be practised for some time before it is known which species is best suited to the Dominion's soil and climate. Also, just because the tree will grow, it does not follow that the oil it produces is going to be exactly what is required by the trade. Therefore, although optimism is usually to be encouraged, it does not do to be like a certain gentleman who, coming to New Zealand from China, where he had seen acres of tung trees, formulated the idea of planting thousands of acres in this country. But his scheme never came to fruition, for Uie very simple reason that the seed to plant was totally unprocurable.

MORE SEED WANTED.

The.tung trees in its native haunts in China grows well on rocky hillsides ■without any special cultivation. It seems to grow well in a poor soil, which it prefers to be acid. In broken eonntry in the warmer districts of New Zealand it is thought that the tree might do well, and the gum lands in tho North are thought to have possibilities. It .is essential, however, to avoid late frosts, which would interfere with the setting' of the blossoms. As a farmer's side-line the tree might be worth growing, but with the price of land what it is, tho orchard cultivation as practised in Florida would not as yet be payable. The whole proposition is in fact at present entirely experimental, and it is- much too early to say whether the production of tung oil in New Zealand can be made profitable.

In the meantime, however, tho trees are growing, and apparently growing ■well. In five or six years after planting .they reach maturity, and have attractive pink flowers in springtime. The trees are deciduous, and grow to a Jieight of about 25 feet. If the Empire Marketing Board's grant enables Kew to send more seed to New Zealand, so that trials may be -made in other districts, no one will be more pleased than the Department of Agriculture.