14 EXPEEIMENTS ON THE APPLE WITH SOME NEW FUNGICIDES. 



lead, the greater part of the insect injuries. Of plat 7, the copper- 

 sulphid mixture gave the same excellent results on the leaves, but 

 produced 15 per cent of russeting on the fruit of the Ben Davis. 



in the supplemental test in the orchard of Mr. Phil Gold, self- 

 boiled lime-sulphur was used in comparison with standard Bordeaux 

 mixture, 3-5-50. Plats 2 and 6 were located in an orchard which 

 had been quite seriously attacked by the cedar rust. The two 

 varieties York Imperial and Ben Davis were in alternate rows and 

 were included in each plat. In the plat sprayed with Bordeaux mix- 

 ture the Ben Davis trees showed 15 per cent of injury to the foliage, 

 and the fruit was considerably russeted. It carried one-half of 1 per 

 cent of cedar rust. The York Imperial trees had about 10 per cent of 

 leaf injury from copper poisoning and had smooth fruit, as usual, 

 but carried 2^ per cent of cedar rust. On the plat sprayed with 

 self-boiled lime-sulphur, corresponding to plat 6 of the main series, 

 there was no spray injury to fruit or leaves of either variety, but 

 there was a marked increase in the cedar rust, about 2 per cent on 

 the Ben Davis and 17 per cent on the York Imperial. Self-boiled 

 lime-sulphur, therefore, did not prove entirely successful in control- 

 ling cedar rust. 



SUMMARY OF RESULTS. 



All types of Bordeaux mixture were injurious. On the Ben Davis, 

 particularly on the fruit, the extent of this injury was so great as to 

 compel the abandonment of Bordeaux mixture for spraying this 

 variety. On the Yellow Newtown, while the fruit suffered very much 

 less, the foliage suffered to a great extent, reaching a damage esti- 

 mated at 80 per cent, the highest percentage of injury produced by 

 any of the sprays. On the York Imperial the fruit was hurt but very 

 little except with neutral Bordeaux mixture. With the ordinary 

 Bordeaux or the modified Bordeaux mixtures the injury was so slight 

 on this variety as to be insignificant and was far overbalanced by the 

 benefits. However, the foliage of the York Imperial suffered seriously, 

 too much to be tolerated if it could possibly be avoided. As the York 

 Imperial is the most immune to copper poisoning of all important 

 commercial varieties as far as fruit is concerned, the net result is that 

 even on that variety, on account of the serious damage to foliage, 

 Bordeaux mixture is to be discarded if other fungicides can be used 

 to do the work without this leaf injury. 



Neutral Bordeaux mixture was the worst form and did more harm 

 than the standard 3-3-50 formula, while the 2-3-50 formula, with its 

 excess of lime, was distinctly superior to the other kinds and gave 

 good commercial results on the York Imperial. In blocks of the 

 York Imperial this 2-3-50 Bordeaux mixture with 2 pounds of arse- 



[Cir. 58] 



