74 SCIENTIFIC REPORTS OF THE AGRICULTURAL RESEARCH 



is necessary before the conclusions of previous authors can 

 be entirely accepted. Spraying experiments with lime 

 sulphur, Berger's lime sulphur and Burgundy mixture 

 failed to check completely the disease. About 5 per cent, 

 of the fruit of a certain variety, on both sprayed and un- 

 sprayed trees, was damaged. 



Apple mildew (Podosphcera sp.) is perhaps the most 

 widespread of the fungal troubles of apple trees in Kumaon. 

 This disease seems to spread rapidly during the month 

 immediately preceding the break of the monsoon. Spray- 

 ing with lime sulphur during this period was not very 

 efficient in controlling the disease, although in one or two 

 cases, in which, at the risk of damaging the tree, a heavy 

 application of double " summer " strength lime sulphur 

 was applied, the disease was brought under control and in- 

 fected shoots produced a further growth of healthy leaves. 

 During 1918 mildew was especially severe on one orchard 

 on which during that year no spraying had been carried 

 out. In 1919 the spraying upon this orchard was done with 

 a mixture containing iron sulphide, prepared according to 

 the formula recommended for the Pajaro Valley, and 

 mildew was very much less than in the previous year. Ex- 

 periments will be carried out during the coming season to 

 test the relative merits of iron sulphide and lime sulphur as 

 sprays against apple mildew. Of the various varieties of 

 apple, " Northern Spy " is the most liable to mildew in 

 Kumaon, and serves as a centre of infection for other varie- 

 ties. It is being destroyed on one orchard. 



Fly speck and sooty blotch (Leptothyrium Pomi) is a 

 disease which, while not actually damaging the apple, 

 affects the market value of the fruit owing to the unsightly 

 markings which it causes on the skin. This disease was 

 much less severe on the trees w^hich had been sprayed with 

 lime sulphur than on trees which had not been sprayed at 

 all. 



Peach leaf curl (Exoascus deformans) had been serious 

 in 1918, and in 1919 certain areas under peach were treated 

 with lime sulphur, Burgundy mixture and Berger's lime 



