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JOUBNAL OF THE ROYAL HOKTIGULTURAL SOCIETY. 



Northern Territory of Australia, and when plants flowered they proved 

 to resemble those from India and Africa. The flowers are white, with 

 yellow anthers on white filaments. The dentate leaves are dark green 

 with irregular dark blotches. — F. J . C. 



Oats, The Blade Blight of : a Bacterial Disease. By j. 



F. Harms, {U.S.A. Agr. Exp. Stn. Ohio, Bull. 210; Oct. 1909).— An 

 abnormal condition of the oat crop due to the above disease seems to 

 have attracted attention in 1890, when it threatened to destroy the j 

 entire crop of oats in the Eastern and Central States. Between that i 

 date and now the trouble has been attributed by different investigators 

 to a variety of causes, such as thrips, grain louse {Macrosifhum ■ 

 granaria), fungus {Fusicladimn destruens) inclement, cold, damp 

 springs followed by hot dry weather, &c. 



After extensive experiments the writer of this bulletin discovered 

 that the blight was due to two species of bacteria, Pseudomonas 

 avenae, a white organism, and Bacillus o.venae, a yellow organism 

 living in symbiotic relationship. 



Inoculation with either organism singly produced limited or no | 

 results, whereas when both organisms were combined they gave rise | 

 to the typical oat blight. Infection takes place mainly through the 

 stomata, rarely through the roots. The organism is present in the 

 soil - and gets splashed on to the leaves during heavy rains. In the 

 early stages spots appear on the leaves. These spots gradually extend 

 until the entire leaves turn first yellow or red, and finally brown, ! 

 when they collapse altogether. 



The crop is affected either by direct infection of the heads by the I 

 organisms or indirectly through the general weakening of the whole ' 

 plant through damage to the leaves. Very frequently the main shoot 

 alone grows and develops, thus making the crop very thin, and splash- j 

 ing during rain is, in consequence, considerable. ! 



Cold, damp weather is very conducive to the rapid development 

 and spread of the disease. 



Infection can also be carried by aphides and other plant hce. ; 

 Inoculations with organisms found inside live aphides gave rise to | 

 typical blight. The blight is not only pathogenic to oats, but also 

 to certain forms of wheat, barley, maize, timothy grass, Poa pratensis, 

 P. compressa, and others. The only remedy suggested by the author 

 is the breeding and selection of resistant strains. 



Sixteen plates are given to illustrate the various stages of the 

 disease, the damage done, and the microscopic and macroscopic 

 characteristics of the two organisms under investigation. — D. M. C. 



Orchard Practice in Ohio. By F. H. Ballou {U.S.A. E.ip. Stn. 

 Ohio, Circ. 94; April 1909; 29 figs.).— This is the first report of the 

 new Division of Horticultural Inspection in this State, and is mainly 

 occupied with the study of horticultural conditions, possibilities, and 

 requirements in different parts of this large area. The writer favours 



