52 Maine; agricui^tural experiment station. 191 i. 



boiled lime-sulphur at several dilutions with and without arseni- 

 cals, self-boiled mixture, bordeaux mixture with lead arsenate, 

 and the latter used alone. 



The results reviewed as a whole again demonstrated an effi- 

 ciency of the sulphur sprays equal to bordeaux in fungus con- 

 trol and reduction of injury to foliage and fruit. Some leaf 

 injury was obtained, but serious defoliation occurred in but 2 

 cases — one when arsenite of lime was used with lime-sulphur, 

 the other when lime-sulphur with lead arsenate was applied to 

 peaches with the carbonic acid gas sprayer. 



Russeting was noted on apples, but of a degree no greater or 

 even less than that effected by the weather on unsprayed fruit. 



Wallace regards foliage injury from lime-sulphur* as entirely 

 distinct from that produced by bordeaux mixture, because of 

 the differences in chemical constituents. He is also of the opin- 

 ion that injury from the former is limited to short periods fol- 

 lowing the application of the spray, and that injuries appearing 

 a considerable time after spraying may be ascribed to the arseni- 

 cals used. In other words, in bordeaux as applied the copper 

 is in the insoluble (hydroxide) or harmless form and cannot 

 cause injury until certain changes occur. In lime-sulphur solu- 

 tion on the other hand, the sulphur is applied in the soluble form, 

 which is then many times more caustic than at any time after 

 it has once dried. 



Wallace also emphasizes the conditions of the leaf as affected 

 by insects and fungi and the vigor of the trees as important 

 factors related to the degree and amount of injury inflicted. 

 The amount of spray applied, according as this is excessive or 

 moderate, is also regarded as bearing on the amount of injury. 



In connection with the above field experiments laboratory 

 studies of the fungicidal properties of lime-sulphur alone and 

 in combination were made.** Spores of peach brown rot, apple 

 scab and apple canker were employed. 



The results show that equal concentrations are not equally 

 efficient for different fungi. Arsenate of lead appears to have 



* Wallace, E. "Spray Injury Induced by L,ime-Sulfur Prepara- 

 tions." N. Y. Agric. Expt. Sta. (Cornell), Bull. 288, (1911). 



** Wallace, E., Blodgett, F. M. and Hesler, L. R. "Studies on the 

 Fungicidal Value of Lime-Sulfur Preparations." N. Y. Agric. Expt 

 Sta. (Cornell). Bulletin 290 (1911.) 



