454 EXPERIMENT STATION EECORD. 



118-122, figs. 2). — ^i\fter a brief discussion of the method of infection by tbe 

 loose smut of these 2 cereals, the authors describe the various recognized 

 methods of seed treatment for combating loose smut, including a discussion of 

 the necessary apparatus and methods of procedure for disinfecting both small 

 and large quantities of grain by either the hot-water or hot-air treatment. 



Field experiments with wheat diseases, 1910-11, J. T. Pridham (Jour. 

 Dept. Agr. Victoria, 9 {1911), No. J,, pp. 2 JO-256).— Attention is called to the 

 general prevalence and serious damage done to wheat crops every year by 

 "take-all" (E. S. R., 25, p. 44) and also to the occurrence of this or a very 

 similar disease on oats and barley. 



The treatment of seed grain with formalin is claimed to have improved the 

 germinating power as well as to have destroyed all external fungus spores. 

 Tables are given showing the prevalence of " take-all " and the results of seed 

 treatment with formalin, copper sulphate, and copper sulphate plus a 2 per cent 

 salt solution. 



Investigations on potato disease (second report), G. H. Pethybridge 

 (Dept. Agr. and Tech. lustr. Ireland Jour., 11 (1911), No. 3, pp. Jfll-W, pis. 

 10). — This is a report on work conducted during 1910 at the temporary station 

 for the study of plant diseases at Clifden, Ireland (E. S. R., 22, p. 746). It in- 

 cludes further studies on the life histories and means of controlling the late 

 blight of the ix)tato (Phytophthora infestans) , yellowing or yellow blight, stalk 

 or sclerotium disease (Sclerotinia sclerotiorum) , Botrytis disease, black stalk 

 rot (Bacillus vielanogenes), Spongospora scab, Rhizoctouia scab (Hypochnus 

 solani), and leaf-roll disease. 



Experiments on the infection of potato plants by wind-blown ascospores of S. 

 sclerotiorum showed that such infection was possible. The author holds that 

 the attacking of the potato plants by this disease occurs chiefly from aerially 

 borne spores and not from the soil. 



Potato plants were also found attacked by a Botrytis which, the author 

 claims, is distinct from the Sclerotinia disease. Observations and cultures 

 failed to show any genetic connection between the 2 fungi, and further, the 

 sclerotia differ morphologically and physiologically. The sclerotia of the 8. 

 sclerotiorum fungus produce ascophores, while the Botrytis sclerotia produce 

 only tufts of conidia. 



In a further study of the black stalk rot (see below) which is said to be 

 caused by B. melanogenes, the author claims to have proved that this organism 

 also rots turnips, swedes, carrots, and parsnips, but not mangels. 



The leaf-roll disease as it appears in Ireland is caused, so it is claimed, by 

 Verticillium alboatrum, the mycelium of which was often found in the brown 

 vascular tracts of the plants, and also in the roots. Plants grown from diseased 

 tubers were affected with leaf-roll disease. 



A bacterial disease of the potato plant in Ireland and the organism caus- 

 ing it, G. H. Pethybridge and P. A. Murphy (Proc. Roy. Irish Acad., 29 

 (1911), No. 1, Sect. B, pp. 1-37, pis. 3). — This is a detailed study of the disease 

 known as black stalk rot and the organism causing it, a preliminary account of 

 which has been previously noted from another source (E. S. R., 24, p. 552). 



The author describes similar diseases, the characters of this disease, the 

 isolation of the causative organism, and its morphological and cultural charac- 

 teristics, discusses its pathogenicity toward other plants, and compares the 

 causative organism with allied species. The disease is characterized by a 

 discoloration and drying up of the foliage, browning of the principal flbrovascu- 

 lar bundles of the stem, decay of the underground portions of the stalk, and 

 rotting of the tubers. The causative organism is called Bacillus melanogenes. 



