FORTIETH ANNUAL REPORT. 153 



serious, and at the end of the season the foliage was in good condition, 

 the apple leaf-spot having been controlled and the cedar rust held in 

 check. It was found also that arsenate of lead used with the lime-sul- 

 phur solution did not result in injury to fruit or foliage and that it 

 controlled codling moth as thoroughly as when combined with Bordeaux 

 mixture. 



EXPERIMENTS OF 1910. 



During the past season further experiments with the lime-sulphur 

 sjjrays were conducted near Wa\iiesboro, Va. A part of the w^ork .was 

 conducted as a demonstration in co-operation with the Bureau of Ento- 

 mology. From seventy-fiiN-e to 200 trees each of Winesap, York Imperial 

 and Ben Davis were sprayed and ten trees of each variety left unsprayed 

 as a check. The principal part of the experiment consisted of four plots 

 treated as follows: 



Plot 1 — Commercial lime-sulphur solution, one and one-half to fifty, 

 with two pounds arsenate of lead. 



Plot 2 — Home-made lime-sulphur solution, two pounds of lime and 

 four pounds sulphur to fifty gallons of water, with two jiouuds arsenate 

 of lead. 



Plot 3 — Bordeaux mixture, three pounds bluestone and four pounds 

 lime to fifty gallons water, with two pounds arsenate of lead. 



Plot 4 — Check, not sprayed. 



The Winesaps were sprayed (1) after the cluster buds opened, just 

 before they bloomed (April 5) ; .(2) as soon as the petals fell (April 

 19) ; (3) tbree to four weeks later (May 17) ; and (4) nine weeks after 

 the i^etals fell (June 20). The Ben Davis and York Imeperial received 

 only three treatments, the first application given the Winesaps having 

 been omitted from these varieties, for the reason that in Virginia they 

 do not suffer seriously from attacks of scab. 



Effect on the Foliage. — The weather w^as unusually cold and wet dur- 

 ing April and May and the conditions were favorable for spray injury. 

 Toward the end of May, soon after the second spraying of the Ben Davis 

 and Yorks, the leaves of these varieties showed considerable spray injury 

 on all the plots. On the lime-sulphur plots the leaves of the young 

 shoots were somewhat scorched around the margins, and as a conse- 

 quence some of them were crooked or curled. A few dead spots appeared 

 on some of the leaves and at that time it looked as though the injui'y 

 might prove serious. It did not progress any further, however, even after 

 the next application, and the trees soon grew out of it. By midsummer 

 nearly all evidence of injury had disappeared and during the remainder 

 of the season the foliage was in excellent condition. In respect to in- 

 juiy there was practically no difference between the home-made and the 

 commercial lime-sulphur. 



Bordeaux mixture caused more injury than either of tlie lime-sulphur 

 preparations and this injury increased as the season advanced. The 

 leaves were more or less spotted with circular brown areas and a consid- 

 erable percentage of them turned yellow and dropped off. The ti^ees 

 sprayed with the lime-sulphur solution went through the season with 

 much better foliage than those sprayed with Bordeaux mixture, demon- 

 strating the superiority of the former fungicide over the latter in this 

 respect. 



The apple leaf-spot disease was controlled equally well by both fungi- 



