41 



gallon tank of mixture the stock solution should he thorouo;hly stirred, 

 and then 2^ gallons of each dipped out, dikited and mixed as de- 

 scribed above. For a 100-gallon tank 5 gallons of each stock solu- 

 tion is used, and each diluted to 50 gallons before mixing. 



Bordeaux mixture according to Formula 6a is ])repared in exactly 

 the same manner as in Fornuila 6, except that slaking the lime and 

 straining the resulting solution is dispensed with. The required 

 amount of lime is weighed out, wet up with water, diluted, and then 

 thoroughly stirred. Stock solutions of hydrated lime can also be 

 used. 



Formulas for Buys and Blights. 



Make a smooth paste of the poiso7is and a little loater; add to the 

 Bordeaux mixture and sLir thoroughly; apply at onee. 



Formula 7. 

 Paris green, ........ ^ pound. 



Bordeaux mixture, ....... 50 gallons.' 



Formula 8. 

 Lead arsenate or disparene, ..... 1 pound. 



Bordeaux mixture, ....... 50 gallons.' 



Formula 11. 



Arsenate of soda stock solution, ..... 1 quart. 

 Bordeaux mixture, ....... 50 gallons. 



Arsenate of soda stock solution is prepared as follows : place 2 pounds 

 of white arsenic and 8 pounds of sal soda in 2 gallons of water. Store 

 in well-stoppered bottles or jugs with a poison label on them. This 

 is a much cheaper poison than Paris green to use with Bordeaux 

 mixture, and it remains in suspension better, but it is not safe to 

 use it alone with lime. White arsenic costs less per pound than Paris 

 green, and will go twice as far, in that 2 gallons of arsenate of soda 

 stock solution will do as much execution as 4 pounds of Paris green. 



Condensed Directions. 



A. For Scab. — Immerse the tubers one and one-half hours in a 

 solution of corrosive sublimate (Formula 1), or two hours in formalin 

 (Formula 2), or disinfect with formaldehyde gas (Formula 10). 



B. For Insects. — Spray with a poison alone (Formulas 3 or 4) . 

 If flea beetles are numerous, or there is danger from blight, use com- 

 bined Formulas 7, 8 or 11. 



C. For Blights. — Begin to spray when the tops are 6 or 8 inches 

 high, and spray thoroughly every ten days, — every week, if neces- 

 sary. If insects are plentiful, use combined Formulas 7, 8 or 11. After 

 danger of in.sects is passed, use Formula 6. 



Usually six and sometimes four sprayings are sufficient to protect 

 against late blight; but the leaves should show a coating of Bordeaux 

 from the time spraying begins till the crop is harvested or the tops 

 are killed by frost. One thorough spraying in rain}^ weather before 

 late blight has gained a foothold may be the most effective applica- 

 tion of the season. If early blight is prevalent, five or six very thorough 

 sprayings, beginning early in the season, are necessary to insure 

 sufficient protection. 



' An ordinary oil barrel liolds about 50 gallon.s. 



