RAGWORT

Hokitika Guardian, 3 December 1929, Page 7

RAGWORT

CHEMICAL KILLER, USED

SUCCESSFUL RESULTS ANNOUNCED.

In the last number of the Agricultural Department’s Journal Air 11. E. R. Grimmett, of the Agricultural Department’s Chemistry Section, gives some particulars about an experiment with ragwort which may be of interest.

This experiment was carried out with the idea of chemically controlling the weed, by Airs Taylor and Mr K. H. Brain, of Kaharoa, Rotorua, in collaboration with the chief chemist and assistant officers’ of the Chemistry Section, and it met with a sufficient measure of success to warrant the publication of at least tentative conclusions. A -CHEMICAL APPLICATION. The method, which was tried on a small scale last summer, and has been adopted more extensively this spring, consists in preparing a mixture of equal parts of filnely crystallised sulphrato of iron and agricultural salt, about an ounce of which is placed in the dry state on the crown of each ragwort plant. It is probably more effective in the spring, when the plants are young and tender, and when each shower of rain dissolves some of the chemical, washing it repeatedlv into the crown and roots. A THOROUGH ERADICATION. Some dozens of plants which had beon thus killed were recently seen by Air Grimmett at, intervals of time varying from a few days up to some months after being treated. In all cases the plants appeared to he completely dead, and many were easily lifted out, the roots being rotten. N> re-growth from the same plants was noticed. In most cases a ring of grass, varying from a few inches to a foot in diameter, had also been killed, but this loss was quickly replaced by tillering from adjacent grass roots. FURTHER WORK TO BE DONE. Although this particular farm wa c only lightly infested with ragwort, it is safe to say that by the method adopted the ragwort has not only been held in check, hut has been noticeably reduced. The original formula suggested by Air B. C. Aston was one part of sulphate of iron to three parts of common salt, but the experiment referred to suggests that a greater proportion, of sulphate of iron is desirable. Further experiments are now being carried out by Mr. Grimmett with the idea of ascertaining the cost of treating extensive and heavily infested areas and of finding out whether the' pronortions of the chemicals used and the application methods could not he improved upon.