Page:The Journal of Indian Botany, Volume III.djvu/310



Vol. III.

ON THE MODE OF INFECTION AND PERENNA- 1ION OF THE SMUT OF “ DOOB ” (CYNODON DACTYLON PERS.)

BY

Harm Chand Mehta M. Sc., Ph. D. (Cantab)

{Professor of Botany, Agra College, Agra)

Introduction

Magnus (4) has recorded as many as three different smuts on Cynodon Dactylon Pers, caused respectively by Ustilago paraguari • ensis, U. Dregeana and U. cynodontis P. Henn, which can be easily distinguished from one another.

Out of these three U. cynodontis P. Henn is the only one, as far as the author knows which occurs in the plains of India and does great damage to “ doob ” an important fodder grass in this country. The author has noticed the presence of smutted doob ” at many places in the United Provinces of Agra and Oudh, the Punjab, Central Provinces and Bihar, and keeping in mind the distribution of the host, it seems highly probable that the disease occurs also in other parts of India. In waste places and on lawns under cultivation one can easily find smutted specimens during the greater part of the year.

prom his unpublished notes, I learn that S. K. Basu, assistant to the Imperial Mycologist at Pusa, carried on some inoculation experi- ments in the year 1906 with the object of finding out whether the host is infected in the seedling stage. Unfortunately he did not get any positive results. In the year 1916 I took up this piece of work at the suggestion of Dr. E. J. Butler, to whom I am very much indebt- ed for casual advice and for the loan of literature from bis library

at Pusa. _.

The work was commenced at Agra and, during the period September 1916— August 1920, numerous inoculations on seedlings of