lo April, 1909.] 



Rust and Smut Resistance. 



-59 



of this smut not onl\ infect the young seedling when they are attached 

 to the gxain, but more commonly infection occurs by means of the diseased 

 straw or flag in the soil. Hence treatment of the seed is not effective, and 

 field experiments are being carried nut to see how far a suitable rotation 

 of crops can mitigate tlie disease. This Flag .smut was first found on 

 wheat in Australia and determined by Wolff in 1873, as being the same 

 as that .so abundant on rye elsewhere and named Urocystis occulta Rah. 

 An experiment conducted at Burnley showed that this was not so, 200 

 grains of Federation wheat were inoculated with the spores of flag smut 

 derived from a crop of wheat grown in the north of Victoria the previous 

 season, and 200 grains of rve inoculated with the same smut. Clean 

 seed of both was sown alongside, the date being 28th June, 1908. The 



CLEAN AND FLAG-SMUTTED WHEAT. 



GRAIN FROM HEALTHY AND 

 DISEASED PLANTS. 



object of this test was simplv to see if wheat and rye could be infected 

 by the same smut. The results were taken on 29th December, and while 

 the wheat was diseased the rye was absolutely clean. There were 190 

 plants of wheat altogether, 21 of which were affected with flag smut and 

 169 clean, so that 11 per cent, were diseased. 



The di.sea.sed plants bore 85 ears and on counting the ears of 21 healthy 

 plants of the .same variety growing alongside, there were 165 or nearly 

 double the number. 



The photograph of the two bundles of wheat, each representing the 

 produce of 21 plants, shows the difference of yield of the healthy and 

 disea.sed. A represents the growth of the healthy plants and B of the 

 diseased, and the proportion of ears in A is nearlv double that of B, 



