420 AGRICULTURE OF MAINE. 



dead or diseased limbs, cankers, or mumified fruit should be al- 

 lowed to remain on the trees or in the orchards. Particular 

 attention should be given to the removal and destruction, by 

 burning, of all rubbish, litter, decaying wood or fruit which 

 might serve as breeding places for fungi or for insects. The 

 good effects of cultivation in the orchard are by no means con- 

 fined to those which tend to make available the food supplies 

 contained in the soil and to the conservation of moisture. It 

 also assists materially in the control of the fungous and insect 

 pests of the orchard, particularly the latter. 



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

 but 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 

 f ruitj while there is much needless destruction of bees and other 

 beneficial insects which work upon the flowers. 



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 ob- 

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

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

 side 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 has already been pointed out (p. 383), the vegetative por- 

 tions of the fungi causing disease are deep within the tissues 

 of the plant beyond the reach of destruction. Hence sprays are 

 of value largely to prevent the entrance of parasites into the 

 healthy tissues and not as agents to kill them after they have 

 once gained entrance. To be successful the spray must be on 

 the fruit or foliage in advance of the spore of the fungus. 



For many years bordeaux mixture has been practically the 

 only spray used on orchard trees for the control of fungous 

 diseases. While it has proven in every way efficient in con- 

 trolling most of the destructive fungous diseases of the orchard, 

 it has been found that the fruit and foliage of certain varieties 

 of apples are frequently injured by the spray. As a rule the 

 beneficial effects resulting from disease control have far out- 

 numbered the ill effects of spray injury. That certain varieties 



