INSTITUTE, PUSA, FOR 1916-17 61 



sclerotial form. Inoculations with the former, which is 

 present on almost all diseased plants, but often apparently 

 in very small quantity, were carried out at Pusa but under 

 somewhat unsatisfactory conditions as the season was far 

 advanced and the available plants old. They gave negative 

 results. Further trials will be made with this and the 

 second fungus. During the enquiry, we were again con- 

 fronted with the probability that there was some condition 

 connected with the chemical composition of the soil in which 

 this root-rot occurred which was the predisposing factor. 

 This condition may be a weak concentration of harmful 

 alkali salts, but the evidence is contradictory in some aspects 

 and further enquiry and experiment will be required. 



Sclerotial diseases of sugarcane and paddy. Dr. Shaw 

 continued his investigations on these diseases throughout 

 the year in the laboratory at Pusa and during a tour to 

 Sindewahi Farm, Central Provinces. The specimens ori- 

 ginally received from the Central Provinces ultimately 

 yielded two sclerotial fungi in culture. One of these was 

 Rhizoctonia destruens, Tass. and the other has not at 

 present been identified. This second form possesses a 

 mycelium which is almost indistinguishable from that of 

 R. destruens but its sclerotia are large, irregular, white 

 bodies very different from those of R. destruens; both these 

 fungi proved to be parasitic upon the leaves of sugarcane. 

 At Sindewahi, however, it was obvious that the most serious 

 parasite was the second, unidentified, sclerotial fungus. 

 This occurred all over the farm on scattered clumps of cane 

 and resulted in the complete death of the outer leaves. The 

 'early stages of attack appeared as red spots on the leaf 

 sheath, the inner side of the leaf sheath being covered with 

 a thick sugary solution containing a fungal growth. As 

 the spot spreads the mycelium forms a thick crust on the 

 interior of the leaf sheath and the sugary solution dries 

 up. Finally the leaf is left as a dry and withered scale and 

 sclerotia are produced along its edges. Cultures were ob- 

 tained at Sindewahi from the mycelium on the leaf, from 

 sclerotia on the leaf, and from sclerotia in the soil. In 



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