114 THE AGKICULTURAL PESTS OF INDIA. 



able difference in this respect between one locality and 

 another. In the Meerut and Eohilkhand Divisions, where 

 winter rains are of regular occurrence, and dense mists often 

 prevail in December and January, it would be difficult to 

 find a wheat-field in which some plants were not attacked 

 by rust, and occasionally considerable damage is suffered 

 from it ; while in the centre and south of the North- 

 Western Provinces it often requires a considerable amount 

 of searching in order to discover such specimens. The 

 commonest of the fungus disease to which wheat is 

 liable is the one known as 'rattua' or 'girwi,' which 

 appears to be identical with the English mildew or rust. 

 The plant tissues become filled with minute orange- 

 coloured spores, which when ripe burst through the 

 plant skin in longitudinal fissures, sprinkling the leaves 

 and ears with a reddish powder. In this condition it is 

 known to botanists under the generic name of Trichobasis, 

 from the fact that each spore is furnished with a short 

 hair - like protrusion or stalk. As the plant ripens, 

 clusters of minute bodies appear, each consisting of a 

 stalk fixed in the leaf tissues, bearing a double-celled 

 head. These bodies grow out in clusters, each cluster 

 appearing to the naked eye a minute black spot. In this 

 stage the fungus is known as Puccinia, and was long 

 supposed to be a separate plant from the Trichobasis, 

 instead of merely a stage in its history. 



When ears of wheat are distorted and thickly covered 

 with a dark brown or black dust, the .plant is infected 

 with the disease known to English farmers as ' smut ' 

 (Ustilago), and to natives as ' kandwa.' The dust is 

 composed of very minute globular spores far smaller 

 than those of Trichobasis, but resembling them in being 

 single celled. Bust does not necessarily altogether 



