DISEASES OF PLANTS. 261 



diseases on Long Island in the season of 1895, which appeared orig- 

 inally as Bulletin 101 (E. S. R., 8, p. 234), and the cucumber ilea beetle 

 as the cause of "pimply" potatoes, which has previously been pub- 

 lished as Bulletin 113 of the station (E. S. R., 9, p. 156). 



The mildew of Lima beans, W. C. Sturgis ( Connecticut Mate Sta. 

 Rpt. 1897, pp. 159-160, Jigs. 4). — Investigations are reported in which the 

 author sought to find the manner in which the beau pods are infected 

 by the mildew of Lima beans (Phytophthora phaseoli). It was thought 

 probable that preliminary information as to the means by which the 

 disease is spread might result in securing means for its prevention. 



Studies of the flower show that bees are the source of dissemination 

 of the fungus spores and that the first attack of the fungus is at two 

 points, namely, the style and the base of the ovary, where the bee, 

 searching for nectar, touches the more moist and delicate tissues of the 

 flower. In most cases where young diseased pods were examined it 

 was found that the infection first appeared at the base or tip — very rarely 

 in the middle. 



The author also shows that wind plays an important part in the 

 dissemination of this mildew. An experiment was conducted in which 

 mildewed pods were brought from a distance and the spores allowed to 

 infect the surface of sound, nearly ripe pods at one end of a row of pole 

 Limas. Within a few days the mildew made its appearance on these 

 infected pods, and within two weeks (the prevailing winds having been 

 in that direction) the disease had spread from one end of the row to the 

 other. 



While from the nature of the disease it would seem probable that 

 the use of fungicides would present many difficulties, yet from experi- 

 ments in which Bordeaux mixture, ammoniacal copper carbonate solu- 

 tion, sulphur, and potassium sulphid were used it appeared that when 

 three applications of Bordeaux mixture was followed by two applications 

 of ammoniacal copper carbonate solution the amount of the disease was 

 greatly reduced. 



The conclusions drawn from the experiments with fungicides show 

 that even in a season most favorable for the Lima bean mildew a thor- 

 ough treatment of the vines with Bordeaux mixture will insure a crop. 

 The selection of well-drained land and a light soil, reducing the number 

 of vines in the hill, and planting the poles erect will insure conditions 

 as little favorable to the development of the fungus as possible. 



On the cause and prevention of a fungus disease of the apple, 

 W. C. Stuegis (Connecticut State Sta. Rpt 1897, pp. 171-175).— During 

 the autumn of 1896 a rather peculiar disease of Rhode Island Greenings 

 and Newtown Pippins was observed. It was characterized by blotches, 

 circular in outline, pale at first and later becoming sooty black and 

 exhibiting under a lens a radiating structure. The individual blotches 

 measured from a quarter to a half inch in diameter, in many cases 

 coalescing and covering the surface of the apple with a sooty coating. 



