Botany. 51 



Various methods of treating diseased trees were also being tried in 

 this and other orchards. Three complete sets of inoculations, con- 

 sisting of ten or more individual infections each, have been made 

 during the past season. Five or more pure cultures of the organism 

 from cankers on apple trees, blighted twigs of apples and pears, 

 and blighted fruits of both apples and pears, have been obtained and 

 tested in various culture media to determine their identity. Over 

 100 photographs of various forms and stages of the canker and twig 

 blight have been obtained. Extensive and detailed data in the 

 shape of notes, correspondence, etc., have been gathered. A paper 

 prepared on the subject, and illustrated with some 30 lantern slides, 

 was presented before the American Pomological Society in session at 

 Kansas City, September 19-21, 1905. 



Briefly the following conclusions may be dra^vn from the year's 

 work : 



a. The disease is quite prevalent and destructive throughout 

 central New York, the Hudson Valley region north of Albany and 

 in the extreme northern part of the state about Chaumont. It is 

 also reported from the southern part of the state. 



b. Trees of from six to 15 years of age suffer worst from this malady. 

 Of the young orchards just coming into bearing in the Hudson River 

 region fully 95 per cent, are badly affected. Old trees also suffer 

 frequently. 



c. The cankers have been proven to be due to bacteria and success- 

 ful inoculations into the healthy bodies of pear and apple trees have 

 been made, resulting in well developed cankers. 



d. By cross inoculations both direct and from pure cultures, the 

 twig blight of pears and apples, and these cankers on apple trees as 

 well as the " Body Blight" of pears have been proven to be due to the 

 same organism. Bacillus amylovoriis. The testing of pure cultures of 

 the organisms obtained from these different sources, through some 

 10 or more different culture media, has shown them to be the same. 



e. The chief methods of infection seem to be: through water- 

 sprouts on limbs or body, wounds, pruning knife, or insects that follow 

 to suck up exuding sap and boring insects, e. g., borers, etc. 



f. The high per cent, of deaths of trees in certain regions seems to 

 be due largely to the work of secondary fungi and bacteria that gain 

 entrance through the infection courts provided by the cankers and 

 cause heart rot of the tree. 



g. Slightly affected trees may be successfully treated as follows: 

 cut out all diseased or cankered tissue, sw ab out with a two-tenths per 

 cent, solution of corrosive sublimate or a thi-ee per cent, solution of 



