Eradication of Charlock. 



19 



freely. Mr. Campbell says : " The strength of the solutions 

 used, viz., 13, 15, and 20 per cent., are perhaps too strong to 

 risk on a large area, though there was certainly no harm 

 done to the oat crop in these experiments. It would be 

 safer, perhaps, to make the experiment at first on a somewhat 

 smaller scale, and to use a 10 per cent, solution/'" 



Interesting experiments have been carried out at the 

 Agricultural College, Uckfield, under the superintendence of 

 Mr. Maiden, the Principal. Twelve plots of oats were 

 sprayed, the oat plants being about five inches high, with a 

 two per cent, solution of sulphate of copper applied at the rate 

 of 25 gallons per acre. It was found that the quantity of 

 liquid was not sufficient, and that 50 gallons per acre of a 

 two per cent, solution was far better, while a dressing of 

 50 gallons per acre of a one per cent, solution of sulphate of 

 copper also caused a most satisfactory clearance of the char- 

 lock. A field of early spring tares, which were not an inch 

 high and nearly smothered by charlock, was sprayed with 25 

 gallons per acre of a two per cent, solution of sulphate of 

 copper. The charlock, which was also very young, was 

 practically killed off while the tares showed well in the rows 

 afterwards, being quite uninjured. Beans were very much 

 blackened, as might be expected from their soft velvety leaves, 

 but they recovered except where the dressings were heaviest. 

 Other experiments were carried out at Castor, near Peter- 

 borough, and elsewhere, also with good results ; and from 

 some of these it was also seen that young seeds sown with 

 oats and barley were not injured by a two per cent, solution 

 of sulphate of copper. 



From the results of the experiments referred to above and 

 from other private trials it now seems to be established 

 that sulphate of copper will kill charlock without injury to 

 corn crops or seeds sown with them, tares, and mangels. 

 The strength of the solution should not exceed two per cent., 

 or 2 lbs. to ten gallons of water, at least when the charlock 

 is young and the corn and other plants with which it is 

 growing are young ; and in many cases a one per cent, 

 solution is preferable. The quantity of the solution used pe r 

 acre should not be less than 25 gallons if it is applied by a 



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