186 SEVENTEENTH REPORT. 



to aeeoimt for the jjreseiice of the Alteinaiia rot from orchards 

 free from otlier diseases. 



It may also be eontliided tliat lead arsenate combined with lime- 

 sulfnr im]»roves the fungicidal value of the mixture as the tests 

 show a uniform decrease in germination over the same strengths of 

 lime and sulfur alone. 



Self Boiled Liine-^Sulfiir. This was ur.xde u]i c(|uivalent to a 

 8-8-50 mixture. This was also repeated with tlie addition of ar- 

 senate of lead at the rate of 2 lbs. to 50 gals. 



PERCENTAGE OP SPORE GERMINATION OX SPRAYED SLIHES. 



Self boiled lime and sulfur 76% germination 



Self boiled lime and sulfur plus lead arsente 67% gcnniiiation 



While this did not reduce germination enough to be effective, it 

 controlled germination more than the 1-40 lime and sulfur. The 

 addition of lead arsenate reduced germination but not so much as 

 in the case of lime-sulfur jdus lead arsenate. 



i<!olnhlc ^Sulfur. This is a patented compound prepared by the 

 Niagara Spray Co. 



PERCENTAGE OF SPORE GERMINATION ON SPRAYED SLIDES. 



Strengths 31/0-200 Si/o-SO 10-50 1-10 1-50 



Soluble sulfur 96% 95% 90% 56% Slfc 

 Sol. Sulfur plus lead 



arsenate 91% 83%' 7% 53% 50% 



The results obtained in this experiment show that it has little 

 fungicidal value; the addition of lead arsenate increased the effi- 

 ciency of the spray as with the other sulfur compounds. 



Botdeauw Mixture. 



PERCENTAGE OF SPORE GiERMINATION ON Sl'RAYED SLIDES. 



Strengths 2-2-50 3-4-50 4-4-50 



Bordeaux and lead arsenate . 23% 12% 10% 



Bordeaux 32% 26% 11% 



These results show" that Bordeaux is more effective than any of 

 the other compounds tried. 



Arsenate of Lead. ' 



