10 EXPERIMENTS ON THE APPLE WITH SOME NEW FUNGICIDES. 



Plat 1, control. — The extent of damage to the leaves of this plat 

 by fungous diseases 'was estimated at 60 per cent on September 21, 

 a week before picking time, and the damage to fruit from fungous 

 fruit spots and insect injuries was estimated at 90 per cent on the 

 Ben Davis (of which slightly more than half was due to the codling 

 moth), 20 per cent on the Yellow Newtown (of which three-fifths 

 was caused by the codling moth), and 10 per cent on the York 

 Imperial (of which three-tenths was codling-moth injury). 



Plat 2, standard Bordeaux mixture. — The fungous damage to the 

 leaves in this plat was estimated on September 21 at 1 per cent on 

 the Ben Davis trees, and the fungous and insect damage to the fruit 

 at 2 per cent. This was merely nominal. On the other hand, the 

 injury to the leaves by copper poisoning on the date mentioned was 

 estimated at 30 per cent, and the fruit russeting at 60 per cent. 

 This was the greatest percentage of damage to any of the fruit by 

 any of the sprays. The only damage of greater extent was that to 

 the Yellow Newtown leaves, which were marked 80 per cent injured. 

 The reverse was true of the Yellow Newtown fruit, only 30 per cent 

 of which was injured. About 25 per cent of the York Imperial 

 leaves was injured, while only 3 per cent of the fruit was injured 

 by spray russeting. 



Since the fruit of the Ben Davis was very susceptible to spray 

 injury throughout, the relative merits of some of the less desirable 

 sprays can be described by giving the percentage of spray injury 

 alone. In the case of some of the following mixtures, therefore, it 

 will be the only figure given. 



Plat 3, iron Bordeaux mixture. — This caused but little more than 

 half the injury of standard Bordeaux mixture. The fruit russeting 

 on the Ben Davis was marked 40 per cent. 



Plat 4) gypsum Bordeaux mixture. — This was just about half as 

 injurious to fruit and foliage as standard Bordeaux mixture. Rus- 

 seting on the Ben Davis was marked 30 per cent. 



Plat o, neutral Bordeaux mixture. — At first this was not quite as 

 injurious as standard Bordeaux mixture, but eventually the fruit 

 russeting on the Ben Davis was so nearly the same as to be indis- 

 tinguishable, and the injury mark given was 60 per cent. Strange 

 to say, this mixture was the only one which seriously injured the 

 fruit of the York Imperial, its use resulting in 20 per cent of injury 

 on that variety. It was therefore more injurious on the whole 

 than standard Bordeaux mixture. 



Plat 6, self -boiled lime-sulphur. — Fruit russeting was practically 

 avoided by the use of this mixture. There was a mark of one-half 

 of 1 per cent of russeting given to the Ben Davis fruit. This was 

 merely nominal, however, and was in the stem end of the apples, prob- 



[Cir. 58] 



