THE HORTICULTURAL SOCIETY OF NEW YORK 



While, of course, it is impossible in a short article to describe fully all 

 the insects and diseases for which spraying should be practiced, still a few 

 helpful suggestions may be given to guide those, who desire to spray 

 fruit trees, to an understanding of the general principles. 



Spraying should be considered under two general heads: (i) in the 

 dormant period ; (2) in the growing period. 



Spraying During the Dormant Period 



Spraying in the dormant period is designed to destroy the San Jose 

 scale, the oyster-shell bark louse, the scurfy scale, etc. ; also to destroy 

 insect eggs, disinfect bark wounds, and generally to destroy lichens and 

 other superficial growths occurring on the trunks and limbs of the trees. 

 The dormant spraying may be done any time after the leaves have dropped 

 in the fall and the leaf scars have had an opportunity to callous over. The 

 materials which may be used during the dormant period are miscible oils 

 or the lime-sulphur solution. The miscible oils should not be used on 

 the stone fruits, except in certain special cases, such as for the control of 

 lecanium or terrapin scale on peaches. It is not advisable to use a miscible 

 oil continuously for several years upon apple trees because, owing to the 

 high penetrating properties of the oil, its cumulative effects may amount 

 to serious damage and ultimately kill the trees. As a rule, a miscible oil 

 should be used only in the case of bad scale incrustation, and as soon as 

 the scale has been cleaned up, then the lime-sulphur solution should be 

 depended upon to keep the trees in good condition. In the case of shade 

 trees and ornamental shrubbery a miscible oil may be used with compara- 

 tive safety, because plants of this kind are more hardy and do not have 

 the delicate bud structures as is the case with fruit trees. 



As a rule, lime-sulphur solution should be used in late winter or early 

 spring, within a few weeks of the time when the buds should normally 

 begin to swell, because the fungicidal property of lime-sulphur solution 

 is one of its most important features, and the availability of this property 

 is much greater as a substantial coating over the twigs and branches of 

 the trees in the early spring if the spraying has been comparatively late 

 in the winter. 



The application of either a miscible oil or lime-sulphur solution should 

 be thorough, but not excessive, especially in the case of oil; the pump 

 should be capable of giving good pressure, and the material should be ap- 

 plied with a fine nozzle, and a calm bright day should be selected for 

 spraying. 



Spraying During the Growing Period 



Apples and Pears. — The principal insects are codling moth, curculio, 

 canker worm and, in some sections, bud moth. The principal fungous 

 diseases to be prevented are scab, bitter rot, cedar rust and frog-eye or 

 leaf-spot. 



