450 EXPERIMENT STATION EECOED. 



sprayed, a second was sprayed on the upper leaf surface only, a tliird on the 

 lower surface only, and a fourth on both sides. Bordeaux mixture was em- 

 ployee! in 1 i>er cent strength May 28 and 2 per cent June 12 and July 2. 



All vines remained clear of the infection to the middle of June when weather 

 increasingly favorable to Peronospora set in. Under the influence of this 

 weather lot 1 became so badly infected by June 21 that the stocks had to be 

 very thoroughly sprayed to prevent loss of all the leaves. These during the rest 

 of the experiment exhibited the ill results of late spraying in case of such 

 weather, 95 per cent of the leaves being attacked and showing an average per 

 leaf of from 10 to 12 points of infection. Early in July plats 2 and 3 also 

 showed attack, the former on from 60 to 65 per cent of the leaves, the latter 

 on about 50 per cent, the latter high percentage being attributed to the increased 

 difficulty of the late spraying from the under side when the leaves were thick 

 and large. Plat 4 was not attacked, which fact is taken to indicate the advan- 

 tage of complete treatment in weather so favorable to Peronspora. It is thought, 

 however, that this may be economically attained and at the same time the 

 flowers and grapes may be better reached by employing a flne spray under high 

 pressure directed obliquely upward. It is considered that these experiments 

 confirm the views of IVTiiller-Thurgau and that they demonstrate the necessity 

 of early and timely spraying, repeated whenever rain falls soon after its employ- 

 ment, but that weaker solution than commonly used may be safely employed. 



A rot of grapes caused by Cryptosporella viticola, C. T. Gregory {Phyto- 

 pathology, 3 (1913), No. 1, pp. 20-23, figs. 2).— While studying the black rot of 

 Niagara grapes in September, 1911, the author observed many berries that did 

 not exhibit the typical black rot effect. Studies were made of these, and as a 

 result of inoculation experiments it was found that the berries were attacked by 

 C. viticola, the same fungus which causes the dead-arm disease of the grapevine 

 and which upon the fruit produces a rot quite similar to the common black rot. 



A new Exobasidium disease of the tea plant, S. Ito and K. Sawada (Rot. 

 Mag. [Tokyo], 26 {1912), No. 308, pp. 237-241. figs. 7; abs. in Mycol Centhl., 2 

 {1913), No. 5, p. 274)- — I'he authors report a disease of Thea sinensis, said to 

 be very serious in the province of Suruga and to be common in the north of 

 Formosa. It attacks the young tea leaves and it is said to be different from 

 E. vexans, being described under the proposed name E. reticulatum u. sp. 



Diseases of the sweet pea, J. J. Taubenhaus and T. F. Manns {Gard. Chron., 

 3. ser., 54 {1913), No. 1385, pp. 21-25, figs. 12).— The authors describe certain 

 diseases of the sweet pea, the investigations of which have been carried on for 

 some time. 



Among those described are the mosaic disease, the exact cause of which is 

 not definitely known. This disease can be artificially induced, and it is thought 

 that under field conditions green aphids are the active agents in its distribution. 

 The disease is considered contagious, but all attempts to discover the organism 

 have as yet failed. 



A description is given of the root rot caused by Thielavia, root rot caused by 

 Rhizoctonia or Corticium, stem or collar rot due to Sclerotinia Ubcrtiana, 

 Fusarium wilt, nematode attacks, anthracnose caused by Glomerella rufomacu- 

 lans, bud drop, or failure to set blossoms, which is attributed to too high fer- 

 tilization with nitrogenous fertilizers, and powdery mildew, which in England 

 is attributed to Erysiphe polygoni and which in the United States has not been 

 definitely determined. 



Notes on some western XJredineae which attack forest trees, II, G. G. 

 Hedgcock {Phytopathology, S {1913), No. 1, pp. 15-17). — In continuation of a 

 previous note (E. S. R., 27, p. 252), the author gives an account of some ob- 



