THE SPRAYING OF PLANTS. 53 



WHEN TO SPRAY. 



The time of spraying will depend upon the purpose in view, 

 lait in no case should spraying be done when the plants are in 

 full bloom. Spraying at this time will often interfere with the 

 fertilization of the flowers, and consequently reduce the crop of 

 fruit, while there is much needless destruction of bees and other 

 insects which work upon the flowers. 



In general, spray early. "Delays are dangerous." Fruit 

 trees should be sprayed before the buds open, potatoes before 

 disease or insects appear. Subsequent treatment will depend 

 very largely upon the nature of the season ; if very wet, it may 

 be necessary to spray every two or three weeks ; if relatively dry, 

 three or four treatments may be sufficient.* 



HOW TO SPRAY. 



Insecticides and fungicides are more effective if applied in a 

 liquid rather than in a dry form, since they adhere to the foliage 

 better. Sprinkling is not spraying. The best results are 

 obtained from the use of a fine spray or mist forcibly applied to 

 the foliage ; and so far as possible, it should reach the under 

 sides of the leaves. A fine mist is preferable to a coarse spray, 

 as there is much less waste of material and much less danger of 

 injury to the foliage. A single dash of the mist is better than 

 continued soaking, as in the latter case the material gathers in 

 drops and runs off or injures the foliage. 



As already stated, spraying for fungi is' a preventive measure 

 rather than a cure. If the surface of the leaf is not completely 

 covered on both sides, with the protective coating, there is still 

 danger of attack. The spores of the fungus may fall upon the 

 smallest unprotected spot. 



Again, while young insects may be killed by a very small dose 

 of poison, a much larger amount will be required as they grow 

 older. So spraying should be commenced early, that the first 

 meal of a young insect may be his last, and in order to insure 

 this end, the poison must be finely divided and evenly dis- 

 tributed. 



* The station has prepared specific directions for spraying; fl) Apples and 

 other fruit trees; (2) potatoes. These will be sent free to any address upon appli- 

 cation. 



