MICHIGAN ACADEMY OF SCIENCE. 187 



PERCENTAGE OF^ SPORE GBRMINATIOX OX SPRAYED SLIDES. 



Streugths 1-50 2-50 

 Lead arsenate 92 7o 86% 



These results show that lead arsenate nsed alone has but little 

 fungicidal value, but wlien combined with the other spray it seems 

 to aid in reducing germination. 



Suinniart/. Many apples in widely scattered regions of the United 

 States are found to be infected with a core rot which is not con- 

 trolled by many of the ordinary sprays used in orchard manage- 

 ment. 



The causal organism is a species of Alternaria which is often 

 mentioned as Longyear's Alternaria. The fungiis is confined to the 

 fruit in the apple, the most common point of entrance seeming to 

 be through the calyx tube. 



Fiinyicides. Lime-sulfur did not i)rove effective in the control of 

 this fungus, as any strength which Avould prevent germination 

 could not be used on the foliage. Self boiled lime-sulfur while it 

 did nut prove an effective agent in preventing germination, showed 

 a greater value than the 1-40 strength of commercial lime-sulfur. 

 Soluble sulfur proved to be slightly more effective than either of 

 the above fungicides. ' 



Lead arsenate when use<l alone showed little fungicidal value, 

 but when combined with other sprays it increased their eflficiency 

 to a very great extent. 



Bordeaux mixture was found to be the most effective fungicide. 

 The weakest dilution gave better results than many of the others 

 in their greatest strengths. 



Michigan Agricultural College, 

 East Lansing, Mich. 



