THE CALIFORNIAN THISTLE.

Otago Witness, Issue 2921, 9 March 1910, Page 21

THE CALIFORNIAN THISTLE.

.Recently at the Harper Adam Agricultural College a systematic attempt by way of experiments has been made to solve the difficulty of destroying the Californian thistle. The report from this college contains a good deal of information, but whioh does not directly apply to the subject of thistle destruction; but the experiments directly bearing on the subject of this note, over a period of two years, are of interest.. A .number of plots were used for purposes of the trial, and numbered as follow*:—Plot 1: Thistles cut three times in ,a season and dressed with 4cwt of common salt after each cutting (midsummer months). Plot lb: Thistles put three times in one season; not salted. "Plot 2: Thistles cut once in season and dressed with 4cwt of ealt at time of cutting. Plot 2b: Thistles out once in season; not salted. Plot 3: Not out, but headed with stick to prevent seeding, and dressed with 4ewt of salt at same time. Plot 3b: Not cut, but headed. Plot 4: Cut once and sprayed with sulphate of copper. Plot. 4b: Uncut, but headed with stick and sprayed with sulphate of copper. The results of the treatment extending over the two seasons were very marked, and are given as follows:—1: That the early cutting had a very beneficial effect, and not only reduced the number of plants, but also so weakened the remaining ones as almost to have cleared the plots. 2: That even a single cutting is beneficial. 3: That spraying with sulphate of copper appears to have little effect. 4: That the application of salt has a good effect in checking the growth if applied during the spring.