FOOD VALUES OF TURNIPS.

Sun (Christchurch), Volume I, Issue 107, 11 June 1914, Page 11

FOOD VALUES OF TURNIPS.

Speaking to a gathering of farmers, Mr W. Robb, an agricultural chemist, gave some interesting particulars of the food content of turnips. Mr Robb explained that he had been engaged for over a year assisting Dr Wilson in his work as >n improver of farm crops, and that much of his time had been occupied with analytical research on turhipsV.A large, number of different varieties of swedes and turnips were grown last year for the purposes of the research.- When the '' roots ? ' were fully matured they were sampled by means of an instrument like a eheese [sampler. The cores 'weTe taken to the laboratory, and the amount of dry matter and sugar ascertained. Some thought that the determination of the specific gravity was a reliable means of judging of the relative value of the roots, but it seemed certain that that method was of very little use. To find the amount of dry ' matter the cores were dried at a temperature of 55deg. centigrade until the weight remained constant. To find the,amount of sugar, cores were pulped in a.machine and the •juice pressed through a linen cloth. The sugar present in the juice, was calculated by chemicaj methods. It was a recognised fact that while turnips and swedes contained a large amount of watet, that water did not contribute in the slightest degree to the feeding quality of the roots. A most important fact was overlooked when it. was supposed that the value of the crop depended on the total weight of produce per aere and not on the net amount of nutritive materials the roots contained. In many cases they might find that roots of enormous size were tasteless and watery, and that the cattle were not very fond of them. In estimating the nutritive value of a crop, water counted as nothing, and, indeed, where it. exceeded a certain percentage it was possibly harmful. The following table showed the composition of certain swed.es in common cultivation, the names meanwhile being withheld:— TURNIPS.

The table, he thought, showed that considerable differences occurred in sugar content, etc. If they were to judge by gross weight, they would say that compared with B, A was very good, but when the weight iOf sugar, was taken into account there was a difference of over 6cwt per.- acre : in favour of B. The point was ;; emphasised when a money value was put; on the: sugar content. The best roots had been kept for seeding. Their progeny would be subjected to a similar process of selection, and in that way it was hoped, as in the case of sugar beet, to gradually raise the feeding value of the turnip crop.

Gross weight Weight of sugar Per cent. per acre. per acre. sugar. ton. cwt. ton. cwt. qr. A .. 3.00 , ,. 41 17 1 5 0 B .. 5.16 , ,. 31 1 SWEDES," .. 1 11 2 0 .. 6.26 : i jv 28 11 .. 1 15 3 D .. 6.83 , ,. 26 ■ 0.5<.. .. 1 16 2