I9Q9-] Summary of Agricultural Experiments. 959 



greater than that from the unsterilised soil. All the tubers from the 

 unsterilised soil were affected. 



Spraying of Potatoes (Univ. Coll. of North Wales, Bangor, Agric. 

 Dept., Bulls. VI., 1906, and II., 1907). — These experiments have been 

 carried on at a number of centres since 1901. The solution consists of 

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

 water. The spraying has invariably produced an increase of the crop. 

 When both sides of the leaves are sprayed, the crop is usually greater 

 than when the upper side only is sprayed. Prof. Winter considers that 

 this is due to the more thorough spraying, and not to the fact that 

 disease gains admission on the under side of the leaves. He observes 

 that " the spraying has no direct effect on potato disease. So far as 

 the disease is concerned, it is of little consequence whether the liquid 

 is applied to the upper or lower sides of the leaves. The copper salts 

 (in a manner not yet explained) so act on the leaves as to give 

 the plants increased vigour, with the result that they keep growing for 

 a longer period, produce a larger quantity of marketable potatoes, and 

 are better able to resist disease." 



This view suggested the question whether the increased vigour due to 

 spraying might not form a substitute for a change of seed. Experiments 

 at three centres in 1907 appeared to show that the old seed, when 

 sprayed, gave a crop almost equal to that of new unsprayed seed. The 

 effect of spraying was still greater on the new seed, and the conclusion 

 is that it would be a mistake to regard the two as interchangeable, 

 and that if the best results are to be obtained both change of seed 

 and spraying should be practised. 



Fruit and Cider. 



Effect of Pruning on Apple Trees; Effect of Grass on Apple Trees 

 (Harper Adams Agric. Coll., Field Expts., 1907). — This experiment was 

 commenced in 1902 with twenty-four trees. In 1907, as in 1906, the 

 unpruned trees formed more buds than the pruned trees. The average 

 increase in diameter of the stem of the unpruned trees is less than 

 that of those pruned regularly, the average diameter of the former at 

 45 ft. from the ground being 1*82 in. and of the latter 2*09 in, 



The results of the experiment to compare the growth of trees when 

 planted on grass or on cultivated ground were given in this Journal, 

 May, 1908, p. 123. 



Planting of Fruit Trees (Woburn Experimental Fruit Farm, Ninth 

 Report, 1908). — This report gives an account of the experiments carried 

 out at Woburn and elsewhere in regard to methods of planting fruit 

 trees. The results are summarised on p. 937 of this issue of the Journal. 



Investigations into Cider (National Fruit and. Cider Institute, Reports 

 for the years 1906 and 1907). — The report for 1906 contains the results 

 of the experimental work as regards (1) ciders made from single 

 varieties ; (2) the rate of fermentation ; (3) keeving, maceration, and 

 filtration ; (4) the influence of yeasts and bacteria on flavour. The 

 report for 1907 deals with (1) the characters of single variety ciders; 

 (2) the storage of cider fruit ; (3) mill tests ; (4) maceration ; (5) the 

 control of the fermenting liquor ; (6) the influence of aeration ; (7) the 

 time of filtration ; (8) the improvement of low quality ciders ; (9) cider 

 sickness; (10) the relations between the quality of the fruit and the 



