66 Diseases of Economic Plants 



2. Overstimulation with fertilizers, especially those rich 

 in nitrogen, is to l)e avoided. 



3. A well-cultivated tree is more inclined to blight than 

 one growing on sod or untilled land. 



4. In irrigated orchards a reduction of the water supply 

 to the minimum has been found effective. 



In nurseries or small orchards or in regions where the 

 blight is not excessive, the disease may be reduced by cutting 

 out and burning every particle of blight when the trees are 

 dormant. Not a single case of blight should be allowed to 

 survive the winter, either in the orchard or within half a 

 mile of it. Every pomaceous tree near by, including the 

 apple, pear, quince, Siberian crab apple, wild cral:) apple, 

 the mountain ash, service berry, and all the species of Cratse- 

 gus, or hawthorns, should be examined for this purpose, the 

 blight being the same in all. The orchardist should not stop 

 short of absolute extermination in every case, for a few trees 

 or branches overlooked may go a long way toward undoing 

 all of his work. Cutting out the blight may be done at an}^ 

 time in the winter or spring up to the period when growth 

 begins. The best time, however, is undoubtedly in the 

 fall, when the foliage is still on the trees and the contrast 

 between the blighted and the healthy limbs is strong. It 

 is further necessary to make a weekly inspection of every 

 tree throughout the growing season, beginning when the 

 blossoms fall, in order to cut out blight whenever it is 

 found. 



In each case it is essential to cut well below any external 

 evidences of the disease. To avoid spreading the infec- 

 tion, in case the pruning tools should accidentally cut into 

 the diseased tissue, the cutting blade should each time be 

 disinfected by wiping it with a cloth saturated with a strong 

 solution of corrosive sublimate (1 part to 1000). When the 

 wound made l)y this excision is at all large, it also should be 

 disinfected with the corrosive-sublimate solution. Particular 

 care should be taken to remove and burn all diseased spurs 

 and water sprouts. 



