INSTITUTE, PUSA, FOR- 1918-19 77 



number of plants are sometimes destroyed in the seed beds 

 from this cause in the neighbourhood of Pusa. On older 

 plants attack cannot be secured unless the humidity is 

 maintained at a high level, and such humidities are not 

 usually found at any but the early period of the growth of 

 the crop in Bihar. Natural attack on plants subsequent to 

 -the seedling stage have not been observed. 



On ginger the disease has long been known and its field 

 characters and control were described by Mr. McRae in 

 1911. It causes a soft rot of the rhizomes and base of the 

 stem in several widely-separated parts of India, and is a 

 disease of much importance to ginger cultivation. As the 

 underground parts are attacked, the disease is found during 

 periods when the soil is moist, and is chiefly confined to the 

 monsoon and early part of the dry weather following. It 

 may thus last almost up to the time when the plants are 

 fully grown. 



On papaya the attack usually takes the form of a foot 

 rot of the base of the stem at or just above ground level, 

 Sometimes the stem higher up is affected. Large areas of 

 soft rotting develop and the tree is often ultimately blown 

 over. As before, the progress of the disease is usually 

 confined to the rainy season. 



The fungus on ginger was formerly identified by the 

 writer as Pythium gracile Schenk, but these further studies 

 have led Subramaniam to separate it from that species, and 

 he has named it P. Butleri n. sp. It is evidently a wide- 

 spread and, at times, destructive parasite in India. 



Definite suggestions for its control have been made, and 

 tested experimentally with good results, by Mr. McRae for 

 ginger and L. S. Subramaniam for papaya. Attempts to 

 check it in tobacco seed beds have proved less successful. 

 Treatment of the soil with the ordinary antiseptics usually 

 recommended has failed, but a treatment by burning dry 

 grass on the surface was effective on a small scale. Further 

 work in this direction is required. 



(6) Pigeon pea wilt. Work on this disease was con- 

 tinued by the writer 1 in collaboration with Mr. Finlow, 



f2 



