Report of State Board of Horticulture. 87 



WHY SHOULD WE SPRAY? 



Liquid fungicides are best applied in the form of a fine raist 

 or spray. This is economy, both in the quantity of material 

 used, and in the time required to apply it. The real object 

 in spraying is to prevent the fungous spores that have lodged 

 upon the foliage, branches or fruit, from germinating and 

 producing fungous growths. Every fungus that grows into 

 a leaf or into a fruit, and thus produces the destruction of the 

 former or the decay of the latter, first lodges on the leaf or on 

 the fruit as a tiny spore. If that spore can be destroyed 

 without injury to the leaf or the fruit, disease may be pre- 

 vented, and therefore the necessity of spraying. 



WHY SHOULD WE SPRAY EARLY? 



As already stated fungus spores are sometimes formed in 

 the fall and remain in open fields all winter uninjured. 

 These spores often lodge in the crevices of the bark of trees, 

 or in other convenient places on the trunk and branches of 

 trees. When the leaves and fruits appear the spores are 

 blown onto these new^ly formed parts and cause them to be 

 diseased. The object in early spraying, even while the trees 

 are still dormant, is to kill the spores that are lodged on the 

 tree and waiting for favorable conditions for development. 

 Again, every spore must remain for a longer or shorter time 

 in a domant state, even after it reaches the proper place for 

 its development, just as seeds remain for a little time under 

 proper conditions for germination before they begin their 

 growth. If the leaves or other plant parts are covered with 

 a fungicide before or immediately after the spores are blown 

 onto them, the spores will be destroyed, and the plant will 

 remain free from disease. 



WHY IS IT NECESSARY' TO SPRAY MORE THAN ONCE? 



After a plant has been sprayed new leaves or fruits are 

 often formed, w^hicli are not covered with the fungicide. Spores 

 may be lodged on these newly formed parts and develop into 

 fungous growths, causing the parts attacked to be diseased. 

 Or the fungicide originally sprayed onto the plant may be 

 washed off by rains, thus leaving the plant unprotected 

 against the spores that are constantly carried about in the air. 



