1910.] Summary of Agricultural Experiments 857 



on at a number of centres since 190 1. It is considered that these experi- 

 ments have shown that spraying produces a large increase in the yield 

 of marketable potatoes, by imparting increased vigour to the plant, and 

 apart from its effect on the disease. In 1908 the experiments were 

 arranged to ascertain the effect of spraying twice at intervals, instead 

 of on one occasion only, and to determine the most suitable time if the 

 potatoes are to be sprayed once only. The trials were made on four 

 one-tenth acre plots at five farms, the dressing consisting of 24 lb. 

 sulphate of copper and 30 lb. pure washing soda, in 120 gallons of 

 water per acre. The average weights of marketable potatoes obtained 

 at the five centres were as follows : — Plot I., unsprayed, 8 tons; Plot II., 

 sprayed once (early), 9 tons 8^ cwt. ; Plot III., sprayed twice, 10 tons 

 1 cwt. ; Plot IV., sprayed once (late), 8 tons 19 cwt. Thus the plot 

 which was sprayed twice produced over 12 cwt. more than the plot 

 sprayed once (early) and 22 cw T t. more than the plot sprayed once (late), 

 and Prof. Winter considers that there can be little doubt that, where 

 possible, potatoes should be sprayed twice. Where they are sprayed 

 only once, a late spraying appears less satisfactory than an early one. 



Experiments were again carried out to ascertain whether spraying 

 could be shown to have an effect on the vigour of the plant where 

 potatoes were grown from new seed, and had thus obtained the increased 

 vigour that change of seed gives. In both years the advantages of 

 spraying both old and new seed were marked, but the best results 

 were obtained from the new seed, and Prof. Winter concludes that a 

 change of seed does not render spraying unnecessary, and if the best 

 financial results are to be obtained, both should be employed. 



Spraying of Potatoes (Edinburgh and E. of Scotland Coll. of Agric, 

 Bull. xvii.). — In 1907 and 1908 experiments were carried out at seven 

 centres in the Eastern counties of Scotland to test the effect of spraying 

 as a preventive of potato disease, and its general effect on the crop. 

 Two sprays were used, viz., a lime spray composed of 12 lb. sulphate 

 of copper, and 6 lb. unslaked lime in 80 gallons water; and a soda 

 spray composed of 12 lb. sulphate of copper and 14 lb. pure washing 

 soda in 80 gallons water. These quantities per acre were applied about 

 the middle of July. In tw r o cases a second application was made about 

 three weeks later. In 1907 the two centres sprayed gave results 

 favourable to spraying, but in 1908, only one centre out of five gave a 

 favourable result. This result may have been due to the dryer climatic 

 conditions in 1908 in East Lothian, one of the driest counties in 

 Scotland; and no conclusions as to the efficacy of spraying are drawn 

 at present. Where a favourable result was obtained, the soda spray 

 did better than the lime spray. 



Finger-and-Toe (Cornwall C.C., Notes on Agric. und Poultry Expts. 

 in 1905 and 1906). — For several years experiments were conducted with 

 lime and other substances, the results showing that while heavy 

 applications of lime were beneficial, the treatment was expensive. In 

 addition, where these heavy dressings (6 tons per acre) had been used 

 mangolds and oats could not be grown successfully for some time. 

 This suggested that oats and mangolds, which appeared, like finger- 

 j and-toe, to be favoured by acidity of the soil, would, if grown con- 

 i tinuously, so reduce the acidity as to free the land from finger-and-toe. 

 j To test this point a field on which previous to 1902 the turnip crop was 



