Tung Oil Tree.

Result of Tests in New South Wales.

WITH the idea of investigating the local possibilities of the tung oil tree, the N.S.W. Department of Agriculture has conducted tests with the tree over a period of some years in various parts of the State. Mr. E S. Clayton, senior experimentalist, who has supervised these experiments, was asked to comment upon the present position, and future prospects of the crop in Australia, and its best method of cultivation.

Intending growers should be wary of over-enthusiastic estimates of prices and returns, and should inquire fully as

to production possibilities and prices before embarking in the industry, Mr.

Clayton said. There was evidence that the tree would grow in the better rain fall districts on the coast and table lands. At Grafton the departmental trees had averaged about 451 b. of dried nuts per tree. Of this weight about 60 per cent, would be actual seed and the remainder hull. These nuts would contain from 30 to 50 per cent, of oil.

A fair yield was generally considered to be from 50 to 701 b. of nuts per tree, at full bearing, and when 58 trees were planted to the acre.

So far as prices were concerned, the position was not very satisfactory. A few years ago the price in London was about £110 a ton. Early in 1932, how ever, the price was only £45 to £50 a ton, and at present the price was still lower. In Sydney the merchants’ whole sale selling price for oil imported from China was about £35/10/ a ton. At this figure prospects were not very bright. While the crop might have pos sibilities in Australia, this depended on a substantial rise in the market price of tung oil. Prospective growers were advised that while the tree was worth testing in the better rainfall districts along the coast and tablelands, the in dustry was still in the experimental stages. The planting out at this stage of large commercial areas was not recommended, where there was any doubt as to the suitability of the climate or soil.

Discussing the general climatic and cultural requirements of the tree, Mr Clayton said that an annual rainfall of not less than 28 or 30 inches seemed to be required, heavier rainfall, of course, being preferable. A hot sum mer and a fairly cold winter appeared to suit the tree. In China, where it thrived, although snow was often present in winter, where the tree yielded best there was generally a minimum of only about four degrees of frost. The trees did not appear to do well where more than 12 or 13 degrees of frost occurred. On the other hand, if the winter was not sufficiently cold to give

the tree a definite resting period and cause it to drop its leaves, the yield was not likely to be satisfactory. The tree was very adaptable so far as soils were concerned. It preferred, however, a slightly acid soil, and did not thrive where the surface soil contained much lime. A deep soil of a sandy or light nature, well supplied with organic mat ter, was very suitable, but the tree grew well on any well-drained fertile soil.

The preparation of the land for planting should be similar to that for planting any farm crop. The soil should be ploughed six or seven inches deep early in the spring, and followed with the harrow to make a good seed bed.

A summer legume, such as cowpeas, should be sown as a cover crop in October, and ploughed in during late autumn. Trees should be planted 116 to the acre, in rows 30 feet apart, with 12½ feet between the rows. When the trees were large enough to begin crowd ing each other, generally about the seventh year, every alternate row should be removed so as to leave the trees in grove formation 25 to 30 feet apart.

Planting the seed in a nursery was the most practical method of propaga tion. The seed should be planted about two inches deep in rows three and a half to four feet apart and 10 to 12 inches apart in the row. November and December were the best months for sowing. Vigorous one-year-old trees were best for winter transplanting.

The harvesting of the tung oil fruit offered no difficulty, added Mr. Clay ton. When the fruits were mature, they fell to the ground, and might be al lowed to lie where they fell until it was convenient to gather them. Alter har vesting, they should be stored in a dry place. The average life of the tree was about 25 to 30 years, but it was probably longer if given attention, especially as it did not appear to be susceptible to insect pests or disease.