Studies on Fungicides — II 



15 



y .9 H /j /s 17 tg ?/ ?3 



Age o/ spores in days 



Figure 2. toxicity of sulfur dust as related to the age of the 

 spore: percentage germination of conidia of sclerotinia amer- 

 ICANA 



TABLE 1. Relation of Spore Age and Toxicity of Copper-Lime Dust, to Percent- 

 age Germination of Macrosporium sarcinaeforme* 



* Data from results obtained by Dr. J. G. Horsfall, formerly "I this laboratory. 



Kind of water 



Among the external factors affecting germination, it is most logical to 



consider first the type of water host suited for the germination of the 

 spores. In general, for this purpose there is distilled, tap, or rain water, 

 the last including lake, stream, and spring waters. The last-named type 



