DISEASES OF PLANTS. 751 



per cent. In the combined treatment of copper sulphate and salt it was found 

 that the fungicide became less effective as the proportion of salt increased. In 

 using fungusine, by far the best results were obtained by keeping the sediment 

 well stirred up. The results to date indicate that immersion in limewater after 

 treatment with copper sulphate is beneficial. As to the combined effects of 

 strength and time of immersion, it was found that reducing the former and 

 increasing the latter gave superior preventive effects, less injury to germination, 

 and a lower degree of reinfection on subsequent exposure. 



A new grass parasite, G. Massee {Roy. Bot. Gard. Eew, Bui. Misc. Inform., 

 1913, No. 6, pp. 205-207, fig. 1). — The author reports and describes a disease 

 first observed in 190S, when the trouble was checked by removing and burning 

 all diseased patches of grass. In 1913 it reappeared in a number of localities, 

 but so far seems to attack only those grasses which are most prevalent in lawns. 



The disease is said to be due to Cladochytrium graminis and investigations 

 with grass seed produced from diseased plants showed that the fungus was 

 carried over in the seed. AVatering a plat of Poa annua with a solution of 

 A lb. sulphate of iron to 1 gal. water checked the disease. The parasite is 

 thought to have been introduced from the continent, as it had not been pre- 

 viously reported as indigenous to Great Britain. 



Cotton anthracnose and how to control it, W. W. Gilbert (U. S. Dept. Agr., 

 Farmers' Bui. 555, pp. 8, figs. 8). — This is a popular description of cotton 

 anthracnose, due to Glomerella gossypii, with suggestions for its control. The 

 methods available for the reduction of loss are said to be the selection of seed 

 free from disease, rotation of crops, combined with fall plowing, and the use of 

 varieties least susceptible to the disease. 



A typical case of curly leaf of cotton in the greenhouse, R. Thiele (Ztschr. 

 Pflanzaikrank, 23 {1913), No. 4, pp. 198-201).— A recent study carried out by 

 the author with reference to that of G. Kranzlin (B. S. R., 25, p. 846) on cases 

 observed in German East Africa leads him to the view that lack of proper 

 nourishment and moisture are the primary causes of this trouble, and that as 

 the result of the consequent weakening of the plant, the cicadas are able to in- 

 flict the further injury noted. It is suggested that better control of the water 

 and food supply of the plants may prove an effective remedy. 



Diseases of ginseng' caused by Sclerotinias, G. A. Osnek {Proc. Ind. Acad. 

 Sci., 1911, pp. 355-364, figs. 6).— Of the 6 or 7 highly important diseases of 

 ginseng, the author here discusses 2, giving results of a recent study thereon. 



Black rot, now distributed in New York and some other States, is said to be 

 caused by a Sclerotinia flourishing best in cold weather; the sclerotia, it is 

 stated, being able also to withstand boiling water for several minutes. It is 

 said to spread from plant to plant through the soil and to be carried on tools 

 and otherwise, and to thrive equally well in alkaline or acid soils. Removal of 

 all suspected roots and disinfection with corrosive sublimate or formalin is 

 recommended, as is also sterilization with steam. The fungus is thought to be 

 able to remain in the soil as a saprophyte for several years. 



Crown rot, reported from parts of New York and as far west as Wisconsin, is 

 said to show at least 2 different types, one attacking the upper part of the stem 

 and the other the root near the crown. Its activity seems to be increased by 

 abundant moisture. The disease is attributed to S. Uhertiana. It appears to be 

 disseminated by both mycelium and spores and to be unaffected by changes in 

 acidity or alkalinity of the soils. Spraying with Bordeaux mixture and the 

 removal and destruction of affected plants are recommended. 



Sugar cane diseases, J. J. Chavanne {Bol. Min. Agr. [Buenos Aires'\, H 

 (1912), No. 8, pp. 738-756, figs. 6).— The author gives the results of some 

 observations and experiments made by himself and others on the several dis- 



