INSTITUTE, PUSA, FOR 1917-18 7S 



laris) was grown on the Pusa farm as a seed crop for the 

 Fibre Expert to the Government of Bengal. The variety 

 grown was that called kakya bombai and about half the 

 area was sown in March and the remainder in June. The 

 early sown portion of the crop grew well, but about the 

 beginning of August a number of plants appeared to be 

 drying up, the leaves falling to the ground and the stems 

 blackening. Inspection of the crop showed that this dis- 

 ease commenced with the formation of a black patch on the 

 stem at a point from 1| — 3 feet above the ground level. 

 This black patch spreads rapidly forming a discoloured 

 band round the stem about 4 — 12 inches long. At this 



stage the leaves of the plant droop and fall and the black 

 band extends up and down the stem, until finally the dis- 

 eased plant is left simply as a blackened stick. 



Examination of the surface of a diseased stem showed 

 the presence of large numbers of pycnidia of a fungus 

 which proved to be identical with that known as Diplodia 

 Corchori Syd. This fungus was first collected as a para- 

 site of jute on Pusa farm in 1910, but until the present sea- 

 son there was no reason for suspecting it of being more than 

 an occasional parasite. As, however, the crop ripened the 

 disease increased until it was estimated that about 20 per 

 cent, of the crop was infected. The fungus was obtained 

 in pure culture and inoculations upon healthy plants suc- 

 ceeded in establishing the disease and proved the parasi- 

 tism of the fungus. 



Inspection of the jute seed crop in other parts of Bihar 

 showed that the disease was in 1917 widespread and, as the 

 Bihar seed crop was intended for seed distribution in the 

 jute growing districts of Bengal, suggested the advisability 

 of disinfecting this seed before sending it to Bengal. The 

 fact, however, that an examination of old specimens of jute 

 in the mycological herbarium at Pusa showed that this fun- 

 gus had, during the past 10 years, been collected, but not 

 identified nor suspected of parasitism, over a large area in 



Bengal, indicated that there was no danger of introducing 



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