1916] DISEASES OF PLANTS. 455 



figs. 9). — An account is given of the leaf spot of celery due to S. apii, with sug- 

 gestions for its control. Experiments are reported in which this blight was 

 very successfully controlled by the use of Bordeaux mixture, large increases 

 in merchantable celery being obtained from sprayed plats over those not simi- 

 larly treated. 



Cotton anthracnose, F. M. Rolfs { Oklahoma Sta. Circ. 40 {1916), pp. 

 3-7). — A description is given of the anthracnose of cotton due to Glomerella 

 gossypii, with suggestions for control measures. These include seed selection, 

 crop rotation, use of old seed, and treatment of seed with hot water and sul- 

 phuric acid. 



Potato diseases in New Jersey, M. T. Oook and H. C. Lint (New Jersey 

 Stas. Circ. 53 {1915), pp. 3-23, figs. 9).— Prepared as a substitute for Circular 

 33, previously noted (E. S. R., 31, p. 52). 



The diseases of the potato, C. R. Okton {Pennsylvania Sta. Bui. 14O {1916), 

 pp. 37, figs. 23). — A description is given of the more prevalent diseases of the 

 potato, with suggestions for their control as far as definite means are known. 



A western fi.eld rot of the Irish potato tuber caused by Fusarium radici- 

 cola, O. A. Pbatt {U. S. Dept. Agr., Jour. Agr. Research, 6 {1916), No. 9, pp. 

 297-310, pis. 4). — In a previous publication (E. S. R., 34, p. 246), Carpenter 

 gave an account of laboratory investigations on potato rots due to species of 

 Fusarium. In the present publication the author gives the results of experi- 

 ments carried out under field conditions in an irrigated region of southern 

 Idaho, where the fungus, F. radicicola, is believed to be well distributed 

 throughout the soils. 



It is claimed that F. radicicola is the cause of a field black rot of potato tubers 

 in this section, the disease being principally confined to round types of potato, 

 such as Idaho Rural and Pearl. It is also capable of causing a jelly end rot 

 similar to a rot of that character on potatoes of the Burbank group in southern 

 Idaho, though under actual field conditions other factors are considered partly 

 responsible in producing this disease. Neither the black rot nor the jelly end 

 rot makes any progress in storage if the potatoes are kept below 50° F. 



As potatoes infected with black rot will bring about an infection of the fol- 

 lowing crop, it is considered probable that the black rot may be controlled by 

 planting sound potatoes only on lands which have been in other crops for a num- 

 ber of years and by providing good conditions for growth. 



Silver scurf of the Irish potato caused by Spondylocladium atrovirens, 

 E. S. ScHULTz (U. S. Dept. Agr., Jour. Agr. Research, 6 {1916), No. 10, pp. 339- 

 350, pis. 4). — The results are given of a study of the silver scurf of the Irish 

 potato, part of the investigation on which was carried on at the University of 

 Wisconsin. The symptoms of the disease, its morphology, histology, etc., are 

 fully described. 



While there is considerable range in spore dimensions, the author concludes 

 that there is but one species and not two, as other investigators have claimed. 

 The fungus is negatively heliotropic, withstands a wide range of temperature, 

 its growth being inhibited at 2 to 3° C, but it is not killed at —10°. Its opti- 

 mum temperature for growth is 21 to 27°, with a maximum of 30°. 



The disease may be carried by infected tubers, and under favorable moisture 

 and temperature conditions may spread to other tubers in storage. Disinfecting 

 the seed tubers with corrosive sublimate reduced very materially the percentage 

 of infected tubers, and warm solutions were found to have a more toxic effect 

 on the fungus than cold ones. 



Notable contributions on diseases and animal enemies of the sugar beet in 

 1914, A. Stift {Bl. Zuckerriibenbau, 22 {1915), Nos. 3, pp. 30-32; 5, pp. 52- 

 61574°— No. 5—16 5 



