EXPERIMENTS WITH FUNGICIDES ON POTATOES. S7 



ready for use, since they only need to be diluted with the 

 requisite amount of water. If one is using much Bordeaux mix- 

 ture this is of little practical importance, for by using stock solu- 

 tions freshly prepared Bordeaux mixture (with allowance for 

 time of preparing stock solution) can be as quickly prepared as 

 the ready made goods can be stirred up and diluted. 



The Cost. Copper sulphate costs at retail, in lots of 50 to 

 200 pounds, about 7 cents per pound. Lime costs about 50 cents a 

 hundred by the cask. Thus the materials for making a barrel 

 (50 gallons) of Bordeaux mixture costs between 40 and 50 

 cents. The prepared goods of this strength are practically as 

 good as the freshly prepared. The small grower will probably 

 find the ready made goods enough more convenient to justify a 

 somewhat higher cost. The large grower should not with present 

 prices pay much more than at the rate of 50 cents for enough 

 material to make a barrel of the mixture. The trouble of pre- 

 paring the mixture from lime and sulphate of copper is slight. 

 Enough lime to make ten barrels of the mixture was weighed 

 out, slacked and strained by the writer in 23 minutes. Making 

 the copper sulphate solution takes practically no labor, although 

 it will be several hours after it is suspended in the water before 

 it will be all dissolved. 



DOES SPRAYING WITH COPPER SALTS PAY? 



In the experiments here reported upon, four sprayings with 

 Bordeaux mixture at a cost, including labor of man and team, 

 of not more than at the rate of $2.50 per acre gave 280 bushels 

 of first-class potatoes as against a yield of 147 bushels of green 

 and too small potatoes to command a ready sale. At the prices 

 which prevailed at time of digging, the crop from the sprayed 

 would have sold for $106.40; $102 for the merchantable and 

 $4.40 for the starch potatoes. The crop on the unsprayed w r ould 

 have sold only with difficulty except for starch, but assuming 

 that the so-called merchantable could have been sold for the same 

 price as the sprayed, the money value of the crop would be 

 $62.60; $53.50 for the good potatoes and $9.10 for the starch 

 potatoes. The investment of $2.50 gave at the least a money 

 return of more than $40.00 per acre. 



To be effective, spraying must be rightly done and at the 

 proper time. Full directions for spraying the potato are given 

 in the article which follows. 





