The Mode of Infection by Smut in Sugar-cane. 
BY 
JEHANGIR FARDUNJI DASTUR, M.Sc. 
Supernumerary Mycologist , Pusa , India. 
With ten Figures in the Text. 
UGAR-CANE smut ( Ustilago Sacchari , Rabenh.) is well known in almost 
O all the cane-growing countries, but as yet the exact details of the 
manner in which sugar-cane is infected with smut have not been worked 
out . 1 Kriiger 2 and Delacroix and Maublanc 3 believe that cane smut is not 
only produced by planting setts taken from infected parents, but also by 
direct infection of healthy plants. Wakker 4 has observed that setts taken 
from stools grown in the neighbourhood of smutted Saccharum spontaneinn 
gave a diseased crop, and therefore Delacroix and Maublanc suppose that 
the spores infected the setts, probably the buds. In Java, artificial inocula- 
tions on cut surface of the setts and also on the buds have given diseased 
shoots in about a year. Ajrekar , 5 in Poona, succeeded in growing diseased 
shoots by planting setts after smearing them with spores. Dr. Butler, the 
Imperial Mycologist, in his unpublished notes, which he has very kindly 
allowed me to consult, says that he did not succeed in duplicating the 
results obtained in Java. He dipped, before planting, a hundred setts in 
water containing smut spores, and only one sett gave a smutted stool. My 
experiments show that the direct infection takes place only in two ways : 
(i) through very tender buds, (2) through old buds only when wounded. 
These results are in direct contradiction to those obtained in Java as far as 
the infection of setts through the cut ends is concerned. As regards direct 
infection there is discrepancy between the results obtained in Pusa, Java, 
and Poona, which perhaps can be explained in the light of the present work. 
It is possible that Dr. Butler, in Pusa, may have used setts from mature 
1 Butler, E. J. : Fungi and Disease in Plants, p. 378, 1918. 
2 Kruger, W. : Das Zuckerrohr und seine Kultur, p. 406, 1899. 
3 Delacroix, G., and Maublanc, A. : Maladies des plantes cultivees dans les pays chauds, 
p. 5 H> 19 11 - 
4 Wakker : Archief voor de Java-Suikerindustrie, p. 929, 1895. 
6 Ajrekar, S. L. : On the Mode of Infection and Prevention of the Smut Disease of Sugar-cane. 
Agr. Journ. India, xi, p. 292, 1916. 
[Annals of Bo‘.any, Vol. XXXIV. No. CXXXV. July, 1920.J 
