12 CONNECTICUT EXPERIMENT STATION, BULLETIN NO. 178. 



spread in varying degrees of seriousness over nearly the entire 

 northern territory where chestnut grows. 



RELATION TO HOST CONDITIONS. 



From our own observation and from the opinions of wood- 

 land owners who have watched the spread of the disease it would 

 seem that the dry seasons, which are unfavorable for the growth 

 of the chestnut, have been an important factor in the spread of 

 the disease. It has been fountl that chestnut growing on dry 

 hill-tops is generally more seriously affected with the blight 

 than that in lower land where there is more moisture. Chest- 

 nut growing on dry hillsides has been evidently killed entirely by 

 dry conditions, as no blight could be found on it. Chestnut 

 injured by fire or in other ways is invariably more quickly 

 attacked by this disease and often it is the trunks of these trees 

 which are infected, thus causing the death of the tree much 

 quicker than if the twigs and small branches were attacked. 



Instead of the chestnut bark disease being an introduced dis- 

 ease as is thought by some, it seems more probable that it was 

 present in this country, growing inconspicuously on dead and 

 dying trees, and that after the chestnut was weakened by a 

 succession of dry seasons it became an active parasite and 

 attacked and killed living trees. 



PRESENT SITUATION AND FUTURE PROSPECTS IN CONNECTICUT. 



The present situation in Connecticut is that the disease is still 

 spreading and unless its progress is checked by some natural 

 causes the future prospects are not bright for chestnut in this 

 state. However, instances have been noted where trees were 

 overcoming the disease and blight cankers which had attained 

 a diameter of eighteen inches were healing over, this healing 

 process having been begun in 1911. This condition is not gen- 

 eral, but if it is possible for some trees which have had favorable 

 growing conditions to overcome the disease we may expect that 

 if the seasons are such that the trees are able to make a more 

 vigorous growth the disease will decrease in virulence consider- 

 ably. Of course, predictions as to the final outcome are at best 

 rather uncertain and evidence at hand furnishes arguments for 



