LIME-SULPHUR vs. BORDEAUX MIXTURE AS 

 A SPRAY FOR POTATOES, IL * 



M. T. MUNN. 

 SUMMARY. 



The experiment herein described is, in the main, a repetition 

 of an experiment made in 191 1. The results of the 1912 experi- 

 ment agree essentially with those obtained in 191 1. Plainly, the 

 lime-sulphur solution is not to be recommended as a spray for 

 potatoes. Six applications of bordeaux mixture prolonged the 

 life of the plants about two weeks and increased the yield of 

 marketable tubers at the rate of 11 1.5 bu. per acre; while rows 

 receiving six applications of lime-siilphur died earlier, even, 

 than the check rows. 



Tipburn, and late blight {Phytophthora infestans) associated 

 with and following which is the common rot of the potato tubers, 

 were the chief diseases encountered in the experiment. Both were 

 largely controlled by bordeaux. Lime-sulphur, on the contrary, 

 dwarfed the plants and aggravated the tipburn, although, so 

 far as could be determined, it did not bum the foliage. The 

 effect of lime-sulphur on late blight and rot i Phytophthora in- 

 festans) is uncertain, but, apparently, it did not check them. 



IXTRODUCTIOX. 



During the year 1911 an experiment designed to test the re- 

 lative merits of lime-sulphur, lead benzoate, and bordeaux 

 mixture, as a spray for potatoes, was conducted; and a detailed 

 report upon it was given by F. C. Stewart and G. T. French 

 in Bulletin Xo. 347 of this Station. It was deemed advisable to 

 repeat this experiment during the past season along similar lines, 

 but to omit the use of lead benzoate as it was conclusively shown 

 that this material possessed no merits as a spray for potatoes. 



•A reprint of Bulletin No. 352. November, 1912: for "Popular Edition," 

 see p. 850. 



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