RAGWORT CONTROL.

King Country Chronicle, Volume XXX, Issue 4845, 14 May 1936, Page 3

RAGWORT CONTROL.

ENCOURAGING EXPERIMENTS. NON-POISONOUS POWDERS. (By Cultivator in "The Dominion.") That the Department of Agriculture is alive to the great necssity for early eradication of ragwort, with which hundreds of farms in different parts of the Dominion are infested, is evident by recent experiments carried out by the Department. These have been mainly with a view to establishing the value of several bisulphates in the destruction of the weed. To those realising the true significance of the position, the results of the experiments are most encouraging. Of the salts experimented with, two are non-combustive and non-poisonous white powders, these being sodium and potassium. Their dry nature renders them convenient for handling and mixing with other compounds, and furthermore, they do not tend to corrode utensils brought into use. It is stated that the sodium bisulphite could be retailed at the principal ports at approximately 3d a pound, whereas the prices of sodium chlorate and ammonium thiacyanate vary from about 4%d to 6d to 8d a pound respectively, according to the quantities purchased. Actually, this means that 10 per cent, and 15 per cent, solution of sodium bisulphite could be made up with no more expense than, say, 5 per cent, to 7% per cent, solutions of the other two chemicals. Experiments conducted in the Rotorua region suggests that a 7% per cent, solution of sodium bisulphite would be effective. If this were the case, as there is every reason to believe it to be so, then the cost would probably not exceed by very much that of the cheapest effective solutions of either sodium chlorate or ammonium thiocyanate. Furthermore, a reduction could be made in the cost of potassium bisulphite to allow for fertilising value of the potash. Further experiments were carried out in the Lower Hutt district, where it was considered that apart from considerations of price and properties of materials, including fertilising values, solutions of 10 per cent, ammonium thiocyanate, 5 per cent, sodium chlorate, 15 per cent, sodium bisulphite, and 10 per cent, and 15 per cent, potassium bisulphate, are almost equally efficient for ragwort destruction. The cost of bisulphite .treatment cannot be ascertained exactly until a sufficient demand exists for the materials to enable manufacturers to produce a suitable grade for weed-killing purposes at a lower cost. "It will also be interesting to see if anything comes of a "new method of control suggested by a conference of ten local bodies from Wairoa to the East Coast held at Gisborne recently. Deep concern was expressed at the rapid spread of ragwort in the past five years, which had meant considerable depreciation in the value of land affected. The suggestion adopted was that legislation should be provided this session so that the control of noxious weeds, particularly ragwort, be taken over by rabbit boards, and subsidised by the Government in a similar manner to rabbit boards. Such a proposal is good in so far as it goes, but what of the areas not covered by rabbit boards?