191 1 •] Summary of Agricultural Experiments. 419 



The spray generally used in Co. Louth, where these experiments were 

 carried out, is Burgundy Mixture, or soda Bordeaux, made with 8 lb. 

 sulphate of copper, 10 lb. washing soda, and 40 gallons of water. With 

 this was compared the Woburn Bordeaux Paste, which is made 

 according to the formula of Mr. Pickering, Director of the Woburn 

 Experimental Fruit Farm. It contains about two-fifths the amount of 

 copper sulphate in ordinary Bordeaux mixture, and no excess of lime, 

 and was found by Mr. Pickering to be much more efficient than the 

 ordinary kind. In addition, milk of lime Bordeaux mixture, containing 

 8 lb. sulphate of copper, 4 lb. quick lime, and 40 gallons of water, 

 was compared with the above two mixtures. 



In 1909 potato blight was not nearly so prevalent as usual, and the 

 results of the experiments were not considered sufficiently conclusive. 

 In 1910 the experiments were carried out at four centres, the soil being 

 a light loam, or, in one case, a limestone loam. At all four centres two 

 plots were tested with the Woburn Bordeaux Paste and the soda 

 Bordeaux mixture respectively, while at three of the centres an unsprayed 

 plot was added, and at two of the centres an additional plot was sprayed 

 with milk of lime Bordeaux mixture. At three of the centres two 

 sprayings" were given, the first during the first week in July, and the 

 second a fortnight later ; at one centre only one spraying was given, 

 viz., in the second week of July. All plots were sprayed at the rate 

 of 120 gallons per acre of the respective mixture at each spraying. 



The blight was very virulent in 19 10. The Woburn Bordeaux Paste 

 proved not nearly as efficient as soda or lime Bordeaux mixture, the 

 haulms dying down much sooner, and the resulting growth of weeds 

 being much greater on the plot sprayed with the paste. Lime Bordeaux 

 mixture gave much the best results, but was only tested at two centres. 

 The plots sprayed with the soda Bordeaux gave, on the average, 23 cwt. 

 of saleable potatoes more, and 3 cwt. of diseased potatoes less per acre 

 than the plots sprayed with Woburn paste. 



Investigations on Potato Diseases (Jour. Dept. of Agric. and Tech. 

 Instruc. for Ireland, Vol. xi., No. 3, April, 191 1). — The Department of 

 Agriculture for Ireland has established a temporary station at Clifden, 

 Co. Galway, for investigating potato diseases, and this number of the 

 Department's Journal contains a full report on the work done during 

 1910. A few points of interest to potato-growers in Great Britain are 

 noticed here. 



"Stalk" or " Sclerotium Disease" (Sclerotinia sclerotiorum Mass). — 

 From observation of the position of the affected part on the plants, and' 

 from experiments, it is concluded here that plants can be infected 

 directly by this disease, by means of air-borne spores, and that the 

 intermediary action of the soil is not necessary. This is contrary to 

 the opinion usually held, which is founded on some experiments by 

 de Bary. The point is of practical importance, for if infection occurred 

 only from the soil at the base of the plant, remedial measures would 

 need to be applied to the plants at such places only, whereas if the 

 infection is more or less general over the plant, the whole of it would 

 require to be suitably protected. A number of methods of checking 

 the disease were tried. These included dressing the soil with quick- 

 lime and with Burgundy mixture, spraying the soil and the plants 



Iwith Burgundy mixture, lime- washing the stalks, dusting the stalks 

 with lime and sulphur, and spraying with liver of sulphur solution. 

 F F 2 



