Second Report on Potato Culture. 69 



spring before plowing the land for potatoes. The yield in 1896 was 

 314 bushels. Without any additional manure or fertilizer the land 

 was again planted to potatoes in 1897, and a yield of 273 bushels 

 obtained from the acre. Five cultivations and four sprayings were 

 given, the first three sprayings being with Bordeaux mixture and Paris 

 green, and the last spraying being with Bordeaux mixture alone. This 

 field was somewhat neglected, owing to the wet August, and the weeds 

 were permitted to grow. While it was late in the season when the 

 weeds were allowed to grow, there is no question but that the yield 

 of potatoes was materially decreased by them. To see what effect 

 weeding would have, four rows were cleaned of the large weeds by 

 hand, and it was found upon harvesting that the weeding had 

 increased the yield at the rate of 30 bushels per acre. The whole 

 potato field should have been kept perfectly clean of weeds until the 

 time of harvesting. A source of material loss to the potato crop is 

 frequently due to the fact that in late summer and early fall the weeds 

 are allowed to grow. 



Bordeaux Mixture. 



No doubt failure to secure satisfactory results from the use of 

 Bordeaux mixture is often due to the fact that the mixture is not 

 properly prepared. While its preparation is very simple, it is possible 

 the very simplicity has caused some to think no great care need be 

 exercised in its preparation. I'his is a mistake, for the success of the 

 application depends upon its being made properly. 



The standard formula for Bordeaux mixture is 



Copper sulfate 6 pounds. 



Lime 4 " 



Water 45 gallons. 



Potatoes will require from two to six barrels of the mixture per acre 

 according to the size of the vines. In case a large area is to be sprayed, 

 it may be well to make up a stock solution of copper sulfate. The 

 following directions for making up the solution may be found helpful. 

 Into a barrel containing 40 gallons of water suspend in a bag or gunny 

 sack 40 pounds of copper sulfate or blue vitriol. It is important that 

 this be suspended near the surface as the solution has a greater specific 

 gravity than water. If it should be put in the bottom of the barrel a 



