46 EXPERIMENT STATION RECORD. 



(Phytophthora infestans), winter rot (Nectria solani), black seal) ( (Edomyces leproides), 

 bacterial disease (Bacillus solanacearum) , and potato seal) (Sorosporium scabies). 

 The effect of these different fungi on the host plants is described, and so far as known 

 the methods of distribution, infection, and means of control are given. 



Potato spraying experiments in 1904, F. C. Stewart, H. J. Eustace, and 

 F. A. Sikkine {New York Stair Sin. Bui. 264, pp. 95-204, pis. 16, map 1).— In continua- 

 tion of the LO-year spraying experiments for the control of potato diseases (E. S. R., 

 1-4, p. 875; 15, p. 7s I i, a report is given of the operations carried on by the station 

 during 1904. 



The bulletin gives the details of 58 experiments in different parts of the State, in 

 which increased yields of potatoes due to spraying are reported. At Geneva 5 spray- 

 ings increased the yield by 233 bu. per acre, while 3 sprayings gave an increase of 

 191 bu. At Riverhead the gain due to 6 sprayings was 96J bu. and to 3 sprayings 

 56^ bu. pei- acre. At this place the flea beetle was the principal enemy. 



In the experiments carried on by farmers in different parts of the State, gains of 

 62j bu. per acre art' reported in one series including 180 acres. This gain w T as made 

 at an average cost of $4.98 per acre, and the net profit, based on the market price of 

 potatoes at digging time, was 824.86 per acre. In another series of experiments 

 carried en with 41 farmers throughout the State, including 363| acres, the average 

 gain due to spraying was 58^ bu. per acre, the net profit received being $22.01 per acre. 



Different fungicides were tested in these experiments, soluble Bordeaux mixture 

 and soda Bordeaux being compared with Bordeaux mixture made with lime after 

 the usual formula. The results obtained were in favor of the use of the lime Bor- 

 deaux, as previously described. It is believed that the efficiency of the soluble 

 Bordeaux mixture may have been reduced by the use of too dilute a solution. 



The authors state that the practice of spraying potatoes for the control of blight is 

 on the increase in New York, and many growers are preparing to spray who have 

 hitherto disregarded this precaution. For 1905 the regular experiments will be 

 continued at Geneva and Riverhead, and efforts made to extend the work through 

 volunteer cooperative investigations. 



Profits from spraying- potatoes, F. H. Hall et al. (Xeir York State Sta. Bid. 

 264, popular >d., pp. 16, Jigs. 3). — This is a popular summary of the above bulletin. 



Notes on Cobb's disease of sug-ar cane, F. F. Smith (Centbl. Bakt. [etc], 2. 

 AbL, 13 {1904), No. 22-23, pp. ? 29-736).— The author gives the results of a study of 

 a disease of sugar cane which was first recognized in Australia by N. A. Cobb (F. S. 

 R., 7, p. 513). The disease is accompanied by a copious exudation of gum, and on 

 this account is sometimes called the gum disease of sugar cane. 



The author investigated the cause and behavior of the disease, concluding that it 

 is of bacterial origin and due to the organism previously described but which by the 

 present system of nomenclature becomes Pseudomonas vascularum. The organism 

 was separated and grown in various media, after which successful inoculation experi- 

 ments were carried on. 



Attention is called to the resemblance between this disease and its cause and that 

 which is known as the sereh disease of sugar cane in Java. 



A bacterial wilt disease of tobacco, Y. Uyeda {Centbl. Bakt, [etc.], 2. AbL, 13 

 {19(>4), No. 9-11, pp. 327-329, figs. 3).— A bacterial disease of tobacco is described 

 which has been under observation at tin- experiment station at Tokyo, Japan, and 

 which is attributed to attacks of Bacillus nicotianse. The disease is said to cause 

 much injury, especially when the transplanting is made late in the season. 



Prolonged moist weather followed by a high temperature favors the development 

 of the disease, which is characterized by a wilting and yellowing of the lower leaves, 

 followed by a blackening of the stem and leaves and finally of the roots. The 

 natural infection seems to take place through the roots, hut the author believes that 

 it may also occur through wounds caused by topping or suckering of the plants. 



