DISEASES OF SPECIAL CROPS 105 



tions for avoiding the blight were deduced, and tested by 

 Waite.^ They have proved their worth in many states.^ 



1. Pruning in winter when the tree is dormant pro- 

 motes growth and favors bUght. Withholding the pruning 

 knife, which may not otherwise be best for the tree, will 

 reduce this tendency. 



2. Overstimulation with fertilizers, especially those 

 rich in nitrogen, is to be 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. 



5. The only really satisfactory method of controlling 

 pear blight (that is, exterminating the microbe that 

 causes it) is 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, including the apple, pear, quince, Siberian crab apple, 

 wild crab apple, the mountain ash, service berry, and all 

 the species of Crataegus, or hawthorns, should be examined 

 for this purpose, the blight being the same in all. The 

 orchard! st 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 his work. Cutting out 

 the blight may be done at any time in the winter or spring 

 up to the period when growth begins. The best time, how- 



' Taken in modified form from M. B. Waitc, U.S. Dept. Agr. Yearbook, 

 1895. 



- Whetzel, H. H., and Stewart, V. B., N.Y. (Cornell) Agr. Exp. Sta. 

 Bui. 272. 



