334 Report of the Horticulturist of the 



most, while the trees in the outside rows were noticeably freer 

 from the canker than those in less exposed situations. 



It has been argued by some persons that the trees, now forty 

 years old, have reached the limit of their usefulness and are dying 

 of old age. However, those trees that are free from canker are in 

 a very vigorous condition, and the fact that cankered limbs occur 

 on much younger trees in widely separated localities and in the 

 best orchards, tends to disprove this theory. IN'either can the 

 trouble in this case be attributed to neglect, unless it be in the 

 matter of spraying, since the orchard has received from the begin- 

 ning practically the same culture that is advocated by our best 

 authorities of to-dav. Sixteen vcars ago the orchard was thinned 

 by taking out each alternate diagonal row of trees. The elder 

 Mr. Chapin was one of the first to spray with insecticides, but the 

 all important point, as it now appears, spraying with Bordeaux 

 mixture, has been neglected. An apparent contradiction to this 

 statement is found in an old orchard not a quarter of a mile dis- 

 tant, that has never been sprayed and has been in sod for years, 

 yet there are very few cankered limbs in any of the trees. It may 

 be mentioned, however, that this orchard is located on a different 

 slope of land and on poorer soil. The soil of the Chapin orchard 

 is for the most part deep and rich and has produced a vigorous 

 growth so that now the trees are very large. 



Severe and unintelligent pruning has also been given as the 

 cause of the presence of canker in this as well as other 

 orchards. While it is admitted that misuse of any kind may favor 

 the development of the canker fungus indirectly, yet the answer 

 to the specific statement is found in the fact that unpruned seed- 

 ling apple trees are found in wood pastures that are badly attacked 

 by the canker fungus. 



In the preliminary studies of the canker certain large, dark 

 colored spores were found, which were at the time supposed to 

 come from some saprophyte; however, cultures were made from 

 them. Agar plate cultures were also made from the diseased 



