33 



The apple leaf-spot disease was controlled equally well by 

 both fungicides and about the same was true of cedar rust. The 

 lime-sulphur solution, however, showed some superiority over Bor- 

 deaux in controlling cedar rust. This disease seems to yield more 

 readily to sulphur sprays than to copper sprays. 



Effect on the Fruit. — There was practically no difference be- 

 tween the lime-sulphur solution and Bordeaux mixture in the con> 

 trol of the diseases that occurred on the fruit. Apple scab, fruit 

 spot and sooty blotch were controlled ecjually well by both fungi- 

 cides. In the case of the Ben Davis, particularly however, there 

 was a decided difference in the appearance of the fruit sprayed 

 with the two kinds of fungicides. The fruit sprayed with Bor- 

 deaux was russeted considerably, although very little of it was 

 dwarfed or distorted as often occurs with Bordeaux sprayed fruit. 

 The Winesaps were also russeted but not so much as the Ben Davis, 

 while the York Imperial showed onlv a slight roughening of the 

 skin. The latter variety is almost immune to Bordeaux russet. 



The fruit of all varieties sprayed with the lime-sulphur solu- 

 tion was almost free from spra}^ russet. The natural russet at the 

 stem end was enlarged slightly and on some specimens this ran 

 over on to the side of the apple, but as a rule, the fruit was smooth, 

 clean, and highlv colored. The high color and general appearance 

 of this fruit would place it in a grade higher than that sprayed with 

 Bordeaux which would mean 25 cents to 50 cents a barrel in price. 



The Control of Apple Scab.^ — In order to determine the com- 

 parative efficiency of the sulphur and copper sprays in the control 

 of apple scab, the fruit from four AA'inesap trees in each plot and 

 six check trees were sorted and the results, in terms of percentage 

 of fruit affected with scab, are given in the following table : 



Table i. — Lime-sulphur solution vs. Bordeaux for apple scab. 



No. of 1 

 Plot. 1 



Spray oNhxtiire Used. 



1 Per cent, of 

 1 scabby fruit 



I. 1 



Commercial lime-sulphur solution to 50) plus 2 



1 



1 



lbs. arsenate of lead. 



1 2.2 



2. 1 



Home-boiled lime-sulphur solution (2-4-50) plus 2 



1 



1 



lbs. arsenate of lead. 



I • 6.1 



3. i 



Bordeaux mixture (3-4-50) plus 2 lbs. arsenate of 





I 



lead. 



I 6.2 



4. i 



Check, not sprayed. 



! 99-8 



It will be seen from this table that the home-made lime-sul- 

 phur solution and the Bordeaux mixture both held the scab down 

 to about 6 per cent, of the crop, while practically all of the un- 

 sprayed frtiit was scabby. The plot sprayed with the commercial 

 solution had the lowest percentage of scabby fruit (2.2 per cent.), 

 but this was probably due to a difference in the plots and not in 

 the fungicides. Plot i contained medium sized trees easily spray- 

 ed, while the trees in plots 2 and 3 were large and rather dif- 

 ficult to sprav with the outfit used. 



It would seem from these results and those obtained in previ- 

 ous experiments that the efficiency of the lime-sulphur solution as 

 a remedy for apple scab could no longer be cpiestioned. 



