68 Wisconsin State Horticultural Society. 



blossoms themselves, going from them to the leaves and twigs. 

 It affected pears and apples alike, both in cultivated ground and 

 in sod. He thought it was caused bj the hot dry air withering 

 the tender petals of the flowers. He believed that the cause was 

 atmospheric. It was most seen in hot, moist weather, and in the 

 trees that are growing most rapidly, and in the tenderest, newest 

 growth. He knew of no remedy but to cut back and prevent 

 rapid growth, or to set the trees where they will make but a slow 

 growth. 



President Smith had noticed trees standing in the sod, 

 which had made but a moderate growth, that had been affected 

 with blight the present season, so that this did not seem to be a 

 sure remedy. 



Mr. Plumb remarked that he had carefully studied this subject 

 for a long time. Ten years ago he expressed the opinion that the 

 direct, the active cause of fire blight lay in atmospheric condi- 

 tions, and his subsequent observations had tended to strengthen 

 rather than to change the opinion then expressed. Occasionally 

 he found those who agreed with him, but the great majority, nine 

 out of ten, at that time claimed that the injury was done by in- 

 sects, but when examination was made they could not discover 

 the insects or find any signs of their having been there. Others 

 claimed that it was the result of fungoid disease. There is no 

 question but that fungus growth is present and is rapidly devel- 

 oped in cases of blight, but that does not prove it to be the cause 

 of the injury. It is far more likely that fungi come in as the re- 

 sult of the disease than that they can attack healthy wood and 

 destroy it. The spores are floating everywhere in the atmosphere, 

 and if they were able to produce the conditions favorable for 

 their development, they would lodge on all vegetation, germinate 

 and soon develop other spores and carry disease and death every- 

 where. The present season, the first half of June was very hot 

 and wet, and blight developed rapidly, then came a warm but dry 

 spell and blight was checked. The last part of June was hot 

 and wet again, and the blight spread as rapidly as before. This 

 connection between atmospheric conditions was seen every year, 

 and gees to prove that the development of blight is governed by 



