PESTS AND DISEASES OF PLANTS 215 



Lead Arsenate. 



There are two kinds of lead arsenate on the market the ordinary, 

 or acid, which is generally used and at times causes severe burning 

 to fruit and foliage if applied too strong, and neutral lead arsenate, 

 which is perfectly safe and should be used wherever there is any 

 danger of burning tender fruit and foliage, or usually in combination 

 when other insects or fungi are to be sprayed at the same time. 



A. Lead arsenate (paste) 4 to 8 pounds 



Water 100 gallons 



B. Lead arsenate (powder) 2 to 8 pounds 



Water 100 gallons 



Mix the paste or powder in the required amount of water or first 

 in a small amount and add the remainder for use. See that the 

 mixture is thoroughly agitated when spraying in order to keep the lead 

 arsenate in proper suspension. 



Lead arsenate is rendered none the less effective when combined 

 with Bordeaux mixture, iron sulfid or tobacco decoctions, but the acid 

 type should never be used in combination with oil emulsions, soap 

 sprays and doubtfully with lime-sulphur. The neutral type, however, 

 may be used safely with any of the above. 



Paris Green. 



If lead arsenate can not be had, Paris green may be used as 

 follows: 



Paris green 1 pound 



Air-slaked lime (or better, dry water-slaked lime) . . 5 pounds 

 Water 200 gallons 



First stir the poison into a thin paste with a little water, add this 

 to the lime, then strain the mixture through a sieve into a tank con- 

 taining the required amount of water. It is particularly necessary to 

 keep this mixture well agitated while spraying. 



As a dust, Paris green is mixed as follows: 



Paris green 5 ounces 



Air-slaked lime 1 pound 



The Paris green and lime are thoroughly powdered, mixed and 

 dusted upon the plants through a muslin bag or by means of a blower. 



Paris green may be effectually used when combined with Bordeaux 

 mixture, but should never be applied in combination with lime-sulphur, 

 soap sprays and emulsions. 



Poison Baits. 



Poison baits occupy a very important place in the control of 

 certain insects, such as grasshoppers, armyworms, cutworms, wire- 

 worms, etc., and are especially useful to the small gardener, though 

 they have often been used with excellent results in large fields and 

 orchards. 



