Flao Smut of ]V//ca/. 



A final experiment was undertaken at Burnley Horticultural Gardens, in 

 which 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 rye inoculated with the same smut. Clean seed of 

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

 test was simply 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 diseased plants bore 85 ears, and on counting the ears of 21 healthy 

 plants of the same variety growing alongsida there w^ere 165, or nearly double 

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

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

 diseased. A represents the growth of the healthy plants, and B of the 

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

 that the number of ears on each plant affected with the Flag smut fungus 

 would be reduced, on an average, about one-half (Fig. 12.) 



In Fig. 13 is shown the grain from the healthy and diseased plants, and the 

 yield from the former is fully three times that of the latter. 



Fig. 12. — Clean and Flagsnuitted Wheat. Fig. 13. — Grain from healthy and diseased plants. 



A. — 21 healthy plants ; B. — 21 diseased plants. A. — 21 healthy plants yielding about 8 oz. of 



grain ; B. — 21 diseased plants yielding exactly 



2i oz. 



The main conclusion to be drawn from these experiments is, that the Flag 

 smut of wheat and rye are not mutually infective, and therefore the name 

 given to Flag smut of wheat by Koernicke in 1877, who received specimens 

 from R. Schomburgk in South Australia, should be retained, viz., Urocystis 

 tritici. 



