1898.] PUBLIC DOCUMENT — No. 33. 67 



A Disease of the Cultivated GsEANroM. 



During the past summer there appeared upon the leaves of 

 some geranium plants upon the college grounds a disease 

 which appears to be different from anything heretofore de- 

 scribed. The plants in question grew in a long border bed, 

 and comprised several ditt'erent varieties. Along the back 

 edge of the bed, trees and low shrubbery hung over to a 

 considerable extent, so that the plants in that portion were 

 quite shaded, while those in front were exposed more directly 

 to the sun. The disease came on in the latter part of July, 

 during the rainy weather then prevailing. The leaves began 

 to turn yellow in small spots, which gradually increased in 

 size, the leaf tissue dying away at those points ; thus the 

 leaves soon became covered with dead spots of considerable 

 size, and finally lost their vitality completely. The plants 

 in the front of the bed were most affected, those in the 

 shaded portion showing little or none of the disease. All 

 varieties, as above mentioned, were equally affected. The 

 plants were sprayed with the Bordeaux mixture, but with no 

 apparent success. The same disease was brought to our no- 

 tice in Northampton and also in the eastern part of the State. 



The trouble appeared to be the result of the attack of some 

 fungus, but investigation of the aff*ected leaves failed to re- 

 veal any such organism. Neither was there any evidence 

 of the presence of insects. Numerous bacteria, however, 

 were found in all affected tissue, and appeared to be the 

 cause of the spotting of the leaves. We do not consider this 

 a genuine disease of the geranium, nor do we expect to find it 

 occurring in the future. That the plants were in a condition 

 of low vitality and hindered growth by reason of the exces- 

 sive moisture, and hence were an easy prey to organisms 

 which ordinarily would be unable to affect them, seems the 

 most probable explanation. The futility of spraying to pre- 

 vent such a disease becomes apparent when its real nature is 

 revealed. 



Some Leaf Blights of Native Trees. 

 During the past season several different kinds of trees 

 have been so generally affected with certain leaf-attacking 

 fungi as to become almost entirely defoliated before the end 



