14 



tigation by several entomologists, notably by Cordley in Oregon, 

 Stewart " in Pennsylvania, and Parrott ^ in New York State. These 

 gentlemen have demonstrated that it is practicable for orchardists 

 to prepare concentrated stock solutions of lime-sulphur wash for 

 immediate or later use. Several orchardists have already adopted 

 this plan, and it will doubtless come into more general use in the 

 future. The details of the preparation of concentrated lime-sulphur 

 solutions can not properly be given in the scope of this circular, but 

 those interested should secure, if possible, copies of reports on the 

 work from the directors of the respective experiment stations. 



SELF-BOILED LIME-SULPHUR WASH. 



In the earlier experiments with the lime-sulpliur wash in the East 

 many efforts were made to avoid the necessity of cooking the wash 

 by utilizing, to dissolve the sulphur, the heat generated by the slak- 

 ing of the lime, or supplementing this by the addition of a quantity 

 of caustic soda or potash. This preparation, formerly designated as 

 sell-boiled lime-sulphur wash, has now largely, if not entirely, fallen 

 into disuse, and the spray under consideration is essentially a (Hffer- 

 ent preparation and was developed priuiarily as a fungicide. 



Ex])eriments made by the Bureau of Entomology in the vicinity 

 of Washington in 190<S, however, have shown that this self-boiled 

 wash, by destroying the J^oung insects and interfering with their 

 establishment, is an excellent summer treatment for the San Jose 

 scale. It is also effective in destroying aphides and, in addition, as 

 stated, will prevent numerous fungous diseases, as established by 

 Prof. W. M. Scott, of the Bureau of Plant Industry. Its use is espe- 

 cially recommended for scale-infested fruit trees which shcndd receive 

 applications of a fungicide and which may be more or less affected 

 with aphides. By the addition of arsenate of lead, at the rate of 2 

 pounds to 50 gallons of spray, the wash also becomes effective 

 against biting insects, such as the codling moth and plum curculio, 

 and this furnishes as nearly an all-around spray as anything at 

 present known. 



It is possible that the commercial concentrated lime-sulphur wash, 

 previously referred to, used at the rate of 1^ gallons to 50 gallons 

 of water, would destroy many of the young San Jose scales. It has 

 been shown to be an excellent fungicide, and at this strength not 

 injurious to the foliage. Arsenate of lead may also be added, as in 

 the case of the self-boiled wash. 



In using the self-boiled lime-sulphur wash as a scale treatment, 

 however, especial pains should be taken to coat the limbs and branches 



a Bul. 99, Pa. State Coll. Agr. Exp. Sta. (State College, Pa.), 1910. 

 bBul. 320, N. Y. Agr. Exp. Sta. (Geneva, N. Y.), 1909. 

 [Oil-. 124] 



