284 DISEASES OF ECONOMIC PLANTS 



In the Geneva and Rivcrhead experiments rows sprayed 

 three times received Bordeaux mixture and Paris green 

 twice and Bordeaux alone once, the dates being July 3, 17, 

 and August 3. Other rows were sprayed six times, twice 

 with Bordeaux mixture and Paris green and four times with 

 Bordeaux alone, the dates being Jul}' 3, 17, August 3, 18, 

 and September 1, IG. Still other rows were not spraj'cd at 

 all with Bordeaux, but were treated twice, Jul}' 3 and 20, 

 with Paris green in limewater to control bugs. The Bor- 

 deaux mixture contained G pounds of copper sulphate to each 

 50 gallons of water and lime to correspond. Paris green 

 was used at the rate of 1 pound to 50 gallons of mixture. 



The recommendation of th(> Geneva Station i< : " Com- 

 mence spraying when the plants are six to eight inches high 

 and repeat the treatment at intervals of 10 to 14 days in 

 order to keep the plants well covered with Bordeaux 

 throughout the season. During epidemics of blight it may 

 be necessary to spray as often as once a week. Usually 

 six applications will be n^quired. The Bordeaux .should 

 contain 4 iiounds of cojiimt sulphate to each 50 gallons 

 in the first two sprayings, and 6 pounds to 50 gallons in 

 subsequent sprayings. Whenever bugs or flea beetles are 

 pl(!ntiful, add one to two pounds of Paris green or two 

 quarts of arsenite of soda stock solution to the quantity 

 of Bordeaux required to spray an acre. 



"Thoroughness of application is to be desired at all times, 

 but is especially important when flea beetles are numerous 

 or the weather favorable to blight. Using the same quan- 

 tity of Bordeaux, frequent light applications are likely to 

 be more effective than heavier applications made at long 

 intervals." 



