S LIME-SULPHUR PREPARATIONS FOR APPLE DISEASES. 



only slightl}^ scarcely enough to be noticeable to the casual observer. 

 At the rate of 2 gallons to 50 gallons of water with arsenate of lead 

 this preparation injured the foliage considerably, so that a small per- 

 centage of the leaves dropped off. (See PL I, fig. 1.) Tliis injury 

 was manifested by a slight scorching around the margins and at the 

 tips of the leaves, and in some cases by the formation of irregular 

 l)rown spots. Even here, however, the injury was scarcely more 

 severe than that caused by 3-3-50 Bordeaux mixture « on the same 

 varieties. (See PI. I, fig. 2.) 



At a strength of 2 to 50 without any poison the commercial solu- 

 tion injured the foliage slightly more than the same mixture with the 

 addition of arsenate of lead. The same is true of the 1^ to 50 strength. 

 The arsenate of lead apparently reduced the caustic properties of the 

 sulphids, rendering the mixture less injurious to apple foliage. This 

 is probably due to the fact that a portion of the sulphur is taken out 

 of solution to combine with the lead, forming lead sulphid and arse- 

 nate of lime. 



The same solution at a strength of 2^ gallons to. 50 gallons of water 

 w-ith and without arsenate of lead injured the foliage very badly, 

 causing a partial defoliation of the trees. This is much too strong 

 for use in the Eastern States, although Professor Beattie,^ of Wash- 

 ington State, recommended even a stronger solution. 



It appears from these tests that 2 gallons of the commercial solution 

 to 50 gallons of water is the maximum strength that can be used 

 on apple foliage with any degree of safety, and that U to 50 is much 

 safer and is about as strong as one should risk in spraying a large 



orchard. 



The home-boiled solution, containing 5 pounds of sulphur and 2^ 

 pounds of lime to 50 gallons of water, with 2 pounds of arsenate of 

 lead, caused very little or practically no injury. This is practically 

 the same as the commercial solution diluted to contain 2 gallons to 

 50 gallons of water, but the foliage injury caused by the latter was 

 more conspicuous. 



The self-boiled lime-sulphur and arsenate of lead caused no injury 

 whatever ; in fact, the fohage sprayed with this mixture had a bright- 

 green, vigorous appearance throughout the season. (See PI. II, fig. 1 .) 

 The leaves were noticeably larger, the buds were plumper, and the 

 trees made more growth than those sprayed with the other lime- 

 sulphur preparations and with Bordeaux mixture. 



The Bordeaux mixture caused considerable spotting and yellowing 

 of the leaves on the York Imperial, Ben Davis, and Yellow Newtown, 



o Whenever formulas for Bordeaux mixture are given in this paper, the first numher 

 indicates the number of pounds cf copper sulphate used; the second, the number of 

 pounds of stone lime; and the last, the number of gallons of water. 



J> Western Fruit Grower, January, 1909. pp. G-7. 

 [Cir. .54] 



