DISEASES OF PLANTS. 541 



liumus, and in no case was it as maiived as wliere large quantities had been 

 used. 



Some noticeable differences in a stand of rye attributed to the use of sul- 

 phur are also reported. 



Failure of wheat seed to germinate normally, G. P. Darnell-Smith {Agr. 

 Gas. N. S. Wales, 26 (1915), No. 3, pp. 231, 232).— Experiments carried out 

 indicate that twisting and consequent failure to emerge from the soil in case 

 of wheat plantlets are due chiefly to deep planting or to setting in case of cer- 

 tain soils. The importance of a properly prepared seed bed is emphasized. 



This explanation does not seem to apply to some cases in which the shoot 

 tip appears to have lost its iisual property of negative geotropism. It is con- 

 sidered possible that a fungus, probably a Podosporiella, which has been found 

 within the seeds, may be a contributing factor in this connection. 



The control of cereal and grass smut and the Helminthosporium disease in 

 Holland and Germany, O. Appel {Phylopathology, 5 {1915), No. 4, pp. 230- 

 232). — The author describes various methods of seed treatment for the control 

 of diseases of cereals and grasses, and he claims that, while Quanjer's method 

 (which consists of spraying the seed grain with a solution of 200 gm. of cop- 

 per sulphate in 2 to 2 J liters of water for each hectoliter of seed) gives good 

 results in Holland, it is less successful in Germany, where the formaldehyde 

 treatment is preferred. Seed treatment with a 0.1 per cent solution of the 

 mercuric salt of monochlorophenol for 10 minutes is said to be as effective as 

 formaldehyde against stinking smut, but anilin dyes and chinosol are less 

 satisfactory. In case of a light attack of Helminthosporium, the mercuric salt 

 above mentioned and chinosol were used with good results, while in a severe 

 attack in 1912 copper sulphate was more^ effective than formaldehyde, but did 

 not entirely stamp out the disease. For the control of Fusarium all the fungi- 

 cides are said to be about equally efficient. 



Stem rot of clovers and alfalfa as a cause of " clover sickness," A. H. 

 Gilbert and D. S. Myer (Kentucky Sta. Circ. 8 (1915), pp. 46-60, figs. 3). — A 

 description is given of a stem rot of clover and alfalfa due to Sclerotinia tri- 

 foliorum, a disease which has been under observation in Kentucky for a short 

 time and which is reported as being destructive in certain portions of the State. 

 Methods of control are suggested. 



Effect of temperature on Glomerella, C. W. Edgerton (Phytopathology, 5 

 (1915), No. 5, pp. 247-259, figs. 4)- — In connection with previous investigations 

 (E. S. R., 23, p. 250), the author found that the hot summer months in Louisi- 

 ana prevent the development of the fungus causing bean anthracnose. 



Following these investigations, he has considered it desirable to test the bean 

 anthracnose fungus, as well as a number of allied species, under laboratory 

 conditions. Forty-nine cultures of Glomerella from 22 different host plants 

 were grown at various temperatures ranging from 14 to 37.5° C. in Petri dishes 

 on agar made from bean pods. Comparisons were made of the growth of the 

 different species, and it was found that the 49 cultures readily fell into six 

 groups, based upon their optimum temperatures for growth as well as their 

 maximimi temperatures. 



The form from the banana, Glcensporium musar'um, has an optimum tempera- 

 ture of 29 to 30°, and a maximum temperature above 37.5°. Forms from 

 various hosts represented by Glomerella cingulata and G. gossypii grew at an 

 optimum temperature of 27 to 29°, and a maximum temperature above 37.5°. 

 The form on the apple and other hosts that is best known by the name Gloeo- 

 sporium fructigeiium has an optimum temperature of 24 to 25°, and a maximum 

 of 34 to 35°. Another form growing on the apple is characterized by a lower 

 optimum and maximum temperature and a slower growth. The watermelon 



