AND COLLEGE, PUSA, FOR 1914-15. 5o 



ment. The species R. Napi West, was found to be a 

 dangerous parasite of mustard and gram. This fungus is 

 incapable of active growth at temperatures above 29°C. — a 

 circumstance which limits its depredations in India. A 

 fertile stage was discovered and found to be identical with 

 the well known Botrytis cinerea Pers., which was described 

 as a disease of mustard by Frank some forty years ago. 

 As a result of this it is considered that R. Napi is not a 

 true member of the genus Rhizoctonia, which should be 

 restricted to those species with a fertile stage in the genera 

 Corticium or Hypochnus. The species R. destruens Tass. 

 was found to be the cause of serious disease of betel vine 

 and potato in Lower Bengal, Bihar and parts of Bombay. 

 In the latter province it also occurred on suran, lucerne and 

 groundnut. There were some indications that the fungus 

 had a perfect stage in the genera Corticium or Hypochnus 

 but no satisfactory proof could be obtained. Experiments 

 suggested that corrosive sublimate was a more reliable 

 fungicide against Rhizoctonia than formalin or copper 

 sulphate. 



In continuation of the research into the blight of opium 

 poppy experiments were conducted with a view to discover- 

 ing whether Rhizoctonia or Peronospora was the chief 

 cause of this disease. Poppy was grown at Pusa from 

 seed supplied by the Opium Department and the resulting 

 crop became infected with P. arbor escens. This fungus 

 was also very plentiful on poppy in the vicinity of Ghazi- 

 pur, but at Patiali Rhizoctonia, and not Peronospora, was 

 found. The matter cannot be regarded as definitely settled 

 but it is probable that Rhizoctonia is only a serious para- 

 site of poppy when conditions such as poor soil or defective 

 drainage are inimical to the growth of the crop. 



(6) Anthracnose. The investigation into anthracnose 

 of betel vine did not yield any results of practical import- 

 ance. There is no doubt, however, that the perfect stage of 

 this C olletotrichum is an ascomycete belonging to the genus 

 Glomerella. Attempts to secure successful inoculations 

 failed and our knowledge of this disease is therefore not 



