80 



INSECTICIDES AND SPRAYING. 



It is applicable against all forms of biting insects ; it kills eater- 

 pillars, locusts, leaf-eating beetles, and other insects which eat leaves. 

 For an average crop of cotton, young juari or maize, pulse, castor, wheat, 



I \ 



FIG. 97. 

 Success Knapsack Machine : leloic-left, Bordeaux nozzle ; right, Verwiorel nozzle. 



etc., from 80 to 100 gallons of mixture are required per acre using 

 from 1 to 1J Ibs. of lead arseniate. This explains its small poison- 

 ous effect on cattle, since there is so little arseniate actually on each plant. 

 An insect eats so large a proportion of food compared to its size, that it 

 absorbs relatively much more of the poison and is killed. Experiments 

 made in the Punjab with bullocks fed on fodder dipped in the mixture 

 showed that no harm resulted, and that freshly-sprayed fodder could 

 safely be fed to cattle. As a matter of practice, the lead arseniate 

 would not remain on a plant after the lapse of a week or longer, and 

 the crop would have scarcely any poison on it after cutting and harvest- 

 ing. In small gardens, in plots of vegetable crops, it is simply applied 



