38 MAINE AGRICULTURAL EXPERIMENT STATION. 



In 1913 two different brands were used. One of these was 

 in the form of a moist paste and apparently had a large amount 

 of very finely divided sulphur, but gave off a distinct odor of 

 hydrogen sulphide, resembling the smell of stale eggs. The 

 other consisted of a dry, yellowish powder which appears to be 

 largely sodium sulphide. While the manufacturers made no 

 statements in the literature which they sent out, claiming that 

 such was the case, many of the purchasers of this latter com- 

 pound in Maine in 191 3 supposed that it was identical with 

 lime-sulphur solution with the water removed. 



The paste was used at the rate of seven pounds to 50 gallons 

 of water and the powder at the rate of two pounds to 50 gallons. 

 One pound of dry arsenate of lead was also added to control 

 insect pests. Three applications were made — one just as the 

 blossoms were showing pink, one after the petals fell, and 

 another about three weeks later. 



The plot sprayed with the fine sulphur paste showed no foli- 

 age injury and scab was well controlled on the leaves throughout 

 the season. On the other hand, while the powdered material 

 was efficient in controlling seal- it produced, when used as above 

 described in combination with the arsenate of lead, very decided 

 injury to the fohage. This began to appear shortly after June 3 

 when the second application of the spray was made, and con- 

 sisted of a spotting and more or less browning of the margins 

 of the leaves. After the third application this injury developed 

 quite rapidly and by July 7 from 75 to 90 per cent of the leaves 

 were affected. This was followed by much yellowing and leaf 

 fall, resulting in quite marked defoliation of the trees. 



The results obtained at harvest time when the percentages 

 of scabby and perfect apples produced on the different plots 

 were determined confirmed the observations made in the summer 

 with reference to the control of the disease on the leaves. Both 

 of the proprietary compounds produced as high or nearly as 

 high percentages of apples free from scab as was obtained 

 where standard dilution lime-sulphur was used. 



In 1914 these experiments were repeated and another pos- 

 sible substitute for lime-sulphur was added to the list. This 

 latter was simply a very finely divided sulphur, much finer than 

 the ordinary flour sulphur of commerce. The chief difficulty 

 encountered in attempting to use pure sulphur in a spray is 



