638 ANNUAL REPORT OF THE OfiE. Doc. 



In conclusion, as the result of this success, all we ask is that 

 you j>ivo us your kind aud cordial sympathy and co-operation, which 

 we have had heretofore. The work that has been started is neces- 

 sary for the coutiuuatiou of your success. We aim to meet the needs 

 of the people, and we invite your friendly criticism. We have the 

 satisfaction of knowing that we have been of public service, aud the 

 gratification of receiving in return, the support and expressions of 

 interest of our friends. 



LIME SULPHUE kSPEAYS FOE THE SUMMEE TEEATMENT 



OF OECHAEDS 



By W. M. SCOTT aud J. W. ROBERTS, Bureau of Plant Industry, V. 8. Department of Agriculture. 



DILUTE LIME SULPHUR SOLUTIONS FOR APPLE DISEASES 



The lime-sulphur preparations for the summer spraying of the 

 apple have been developed not because Bordeaux mixture has not 

 proved to be a good fungicide, but because it often injures both 

 fruit and foliage to a very serious extent. On the fruit of many 

 varieties the injuries caused by Bordeaux appear as russeted streaks 

 or areas. Often, too, many of the ap])les are drawfed or badly dis- 

 torted. The applications made within three or four weeks after 

 the blossoms fall are largely responsible for these injuries, which 

 are particularly serious in a wet spring. 



Midsumjuer or late spraying, such as that required for bitter rot, 

 seldom russets the fruit since by that time the tissues of the skin 

 have become more mature and are accordingly less tender. The 

 skin of the young fruit is injured by the copper, the injured parts 

 enlarging with the development of the apple and finally forming the 

 familiar russet spots and streaks. In wet seasons russeting of fruit 

 may be so serious as to reduce its market value 25 per cent, or even 

 50 per cent, in some cases. 



Lime-sulphur preparations then, comprise the results of an at- 

 tempt to find a summer spray of less causticity than Bordeaux 

 mixture but possessing its fungicidal powers. During the past four 

 years the Bureau of Plant Industry, and some of the experiment 

 stations, have been conducting experiments with lime-sulphur fung- 

 icides and the results have been such as to warrant the recommenda- 

 tion of a lime-sulphur solution as a partial substitute for Bor- 

 deaux mixture. 



THE LIME-SULPHUR SPRAYS 



The lime-sulphur preparation used for summer spraying is but 

 a weak modification of the old wash, long used as a dormant spray 

 for scale and peach leaf curl. Concentrated lime-sulphur solution 

 may be made at home by boiling lime and sulphur in water, or it 

 may be purchased already made up, requiring then merel;^ dilution 

 .to make it ready for use. 



