10 FARMKRS BULLETIN 867. 



COST OF ARSENATE OF LEAD. 



In 1!)16 tlio {:j;ia(lo of powdorod ai'soiiate oi load rocommondod for 

 treating tobacco retailed at prices ranging from 20 to 30 cents per 

 pound; very little, howeror, being sold for more tlian 25 cents per 

 pound. By clubbing together farmci-s may find it possible to buy 

 someAvliat cheaper direct from the factory. At 25 cents per pound 

 the fii-st application of ])o\vdered ai-sonate of lead will cost from 87^ 

 cents to $1 per acre, and at 1916 price^s the 5-pound dosage recom- 

 mended for large tobacco will cost $1.25. With Paris gi-een, a H- 

 pomul dosage woidd cost from 60 to SO cents, and a 2-pound dosage 

 woiUd.cost from 80 cents to $1. At present, therefore, it is apparent 

 that ai-senate of lead is alint)st as cheap as Paris green, and when its 

 greater lasting qualities are taken ii\to consideration it is cheaper. 



SUMMARY. 



Paris green, although an elective insecticide, frequently burns 

 tobacco very severely and may reduce the value of the crop by as 

 much as 50 per cent in exceptional cases. 



Ai-senato of lead never seriously hijures tobacco even under tlie 

 most unfavorable conditions. 



A dosage of Paris green large enough to be effective against honi- 

 worms can not be applied without grave danger of burnhig tobacco. 



Paris green, which is applied in dust form without a carrier, is 

 used at the rate of from 1 to 2 pounds per acre. 



Ai"senate of lead is safe and eil'ective durhig rainy weather, whereas 

 Paris green is dangerous anil ineffective. 



It is recommeniled that ai-senate of lead be used against the tobacco 

 hornworms and that it be applied as a dust or powder. 



The dosage of ai-senate of lead in powdereil form varies from 3^ 

 pounds to 5 pounds per acre. If applied as a spray, use from 3 to 

 4 pounds in 100 gallons of water. 



To apply arsenate of lead in powdered form, without a carrier, 

 use a dust gun having a fan diameter of at least 10 inches and a 

 special device for preventing clogghig of the delivery pipe. If a gun 

 with such a device is not used, it will be nocessar}' to mix the ai-se- 

 nate of lead thoroughly with equal parts of dry wood ashes. 



Apply ai-senato of lead when there is no brooze and when dew is 

 on the plants. 



Use only sucli hramh of arsenate of lead as arc guaranteed to contain 

 at least SO per cent of arsenic oxid, of which not more than 1 per cent 

 is free, or water-soluble. 



