1922.] Liver Rot in North Wales, 1 . L61 



cent, solutions, using Holder Pneumatic and " Mysto " Knap- 

 sack sprayers. It was found that from 100 to 120 gallons per 

 acre was required to wet the surface, and the spraying had to 

 be most carefully done owing to the adverse conditions. The 

 solution 1/1000 did not give satisfactory results, and several 

 plots failed to give conclusive evidence, since, although snails 

 were abundant enough when sprayed, but few could be re- 

 covered a few days later. This was attributed to the activities 

 of a number of Lapwings which frequented the plots between 

 the time of spraying and the subsequent counting of the snails. 

 However, one plot in another field sprayed with 1 per cent, 

 solution yielded 112 snails, all dead, on 6th June (100 per cent, 

 killed), while of 02 snails collected alongside the plot, on un- 

 sprayed ground, 52 were living 



In the following week several Jong and deep ditches near 

 Conway heavily populated with both L. truncatula and 

 L. peregra (an allied, but larger species) were cleared of rank 

 vegetation, and sprayed with 1 per cent, solution of copper 

 sulphate on 6th June. The ditches contained no water, but 

 were still damp, and the snails living. On 14th June ditch (a) 

 (160 yd. x 1 yd.) gave 72 per cent, dead snails, and ditch (b) 

 (84 yd. x 1 yd.) 100 per cent. dead. Subsequently, the cost of 

 this type of spray was worked out for 5 acres so treated in 

 Anglesey by a farmer. A horse -thaw n 40 gallon barrel sprayer 

 was used, 100 gallons of 1 per cent, solution being applied, 

 and the cost was 6s. per acre. 



Subsequently, in October and November, a series of trials 

 was made, using powders, which were distributed by means 

 of hand bellows, and a Knapsack dry sprayer. This method 

 proved very successful for narrow ditches and small wet patches, 

 but did not give good results when tried on larger plots on the 

 open field. The expense also was considerably higher than in 

 the case of the copper sulphate solutions, the lowest cost 

 working out at 16s. per acre. Nevertheless, this appears to 

 be an excellent way of treating narrow ditches and small wet 

 areas, being easy to carry out. The hand bellows gave the 

 best results. The following are some of the typical results : — 

 fl) Copper sulphate in powder form was first tried mixed with 

 fine slaked lime as a dilutant and spreader. Lime was soon 

 abandoned owing to a reaction with the copper sulphate, and 

 being too light to ensure even spreading of the heavier copper 

 sulphate; (2) one part copper sulphate mixed with two parts 

 flour gave even distribution and excellent results, but flour was 



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