MAINE APPLE DISEASES. 349 



It has been claimed that Hme-sulphur sprays do not cause 

 leaf-spot. The experiments already referred to (p. 346) which 

 were conducted by Mr. Bonns in 1910 with lime-sulphur and 

 similar substitutes for bordeaux mixture used with lead arsenate 

 as an insecticide, indicate that exceptions to this statement 

 may be expected when these sprays are tried on the more tender 

 varieties like the Ben Davis. 



Experiments conducted at Orono by the writers in 1908 and 

 1909 with self -boiled lime-sulphur in comparison with bordeaux 

 mixture on Alilding, Fameuse and Mcintosh resulted in no in- 

 jury with either spray. Moreover published reports of spray- 

 ing apple trees in Arkansas, Oregon, Missouri, New York and 

 New Hampshire, with self-boiled, home-cooked and certain of 

 the commercial lime-sulphur sprays are agreed as to the absence 

 of spray injury from lime-sulphur. However, in our own ex- 

 periments and in .some of the others mentioned the trees used 

 were not those which are particularly susceptible to bordeaux 

 injury, and while the results are of value as showing the fungi- 

 cidal value of lime-sulphur, they do not show that it would not 

 produce spray injury on the more tender varieties. Aluch more 

 experimentation will be necessary to determine this point ; hence 

 it is impossible at this time to state with any degree of accuracy 

 what may be expected from the lime-sulphur sprays in the line 

 of spray injury. However, there is every reason to believe that 

 it may be used on the more tender varieties with much less dan- 

 ger of injury than with bordeaux mixture. It is probable that 

 the combined use of the two would yield the more satsifactory 

 results. That is, for the more tender varieties, use bordeaux 

 mixture for the first spraying, in the spring before the leaves un- 

 fold, followed with lime-sulphur for the later sprayings. 



Baldwin spot. The disease which is generally known in 

 Maine under this name is not of fungus origin. It takes its 

 name from the fact that it was first observed on and occurs most 

 commonly on Baldwin apples, but it is not confined to that va- 

 riety. 



This disease is characterized by sunken spots distributed irreg- 

 ularly over the surface of the apple, as shown in Fig. 242. These 

 spots are somewhat hemispherical in shape. They vary in size 

 from one-eighth to one-fourth inch in diameter and have very 

 much the appearance of l)ruiscs. :\n examination of the tissues 



