PKAK GROWING IN CALIFORNIA. 347 



gouge any suspicious portions of the trunks and branches. In this way 

 cankers may be discovered which otherwise would remain, with the 

 possil)ility of their disseminating the disease during the growing season. 

 The type of gouge used is shown in Fig. 147d. The frequent disinfec- 

 tion of the gouge to prevent inoculations is absolutely necessary. 



Not all cases of blighted branches discovered during the dormant 

 season Avill transmit the disease to other trees because of the fact that 

 the bacteria may die and the disease thus become inactive. Cases of 

 this nature are very commonly found offering excuses for the care- 

 less man to neglect his orchard hoping that the blight will die out of 

 its own accord. Again, it is not safe to take chances and whenever a 

 case of holdover is found it should be removed because of the possi- 

 bility that it is in a live condition and therefore capable of spreading 

 the infection to other branches or other trees. 



Control. 



As early as 1895 Mr. M. B. AVaite, who w^as at that time assistant 

 in the Division of Vegetable PhysiologA^ and Pathology, U. S. Depart- 

 ment of Agriculture, published an article on the cause and prevention 

 of pear blight in the year book of the Department of Agriculture. In 

 this article Mr. Waite gave much splendid advice which pear 

 growers would do well to follow today. After the pear blight made its 

 appearance in California and threatened to very materially injure the 

 industry in certain parts of the state, the Department of Agriculture 

 came to the aid of our growers and in the year book of 1906 we find a 

 report of the Bureau of Plant Industry, from which we quote as 

 follows : 



"The Department has worked out by careful bacteriological investi- 

 gation, methods of controlling this serious menace to the pear and 

 apple industry. The disastrous attacks of the old eastern pear blight 

 upon the magnificent pear orchards of California have brought into 

 prominence the importance of this work. During the past six years 

 the Department has been engaged in demonstrating on a small scale 

 in certain isolated orchards the practicability of controlling the dis- 

 ease, mainly by the eradication of the blighted portions of the tree and 

 the antiseptic treatment of the wounds. Strenuous efforts are being 

 made by the Department, in cooperation with the State Experiment 

 Station and the state and county horticultural commissioners of Cali- 

 fornia, to assist in applying these methods in saving the California 

 orchards. ' ' 



There are tAvo methods that may be used successfuly in controlling 

 the blight. The first, or cutting metliod, has been generally adopted in 

 the past, and since the days when Waite demonstrated that by taking 

 the proper precautions, blight removal would save the trees and 

 orchards, hundreds of orchardists have carried on an effective campaign 

 against the disease. The second method, which is newer but wliich 

 promises to be by far the most practical and economical is the propa- 

 gation of trees on roots and trunks that are resistant or immune. Great 

 progress in the work of finding resistant or immune varieties and species 

 has been made by the Southern Oregon Experiment Station, under the 

 immediate direction of F. C. Reimer of Talent, Oregon. 



9—37406 129 



