INSTITUTE AND COLLEGE, PUSA, FOR 1910-11. 53 



It is probably responsible for a reduction of the yield 

 which may be much greater than the cultivators themselves 

 suspect, but no treatment can be recommended as yet. 



(e) Wilt diseases. — Experiments carried out at Pusa 

 and independently by the Mycological Assistant of the 

 Bombay Department at Poona, have demonstrated that the 

 fungus which causes rahar (pigeon pea) wilt produces viru- 

 lent spores on the stem of diseased plants. Hence it is ad- 

 visable to pull out attacked plants early. Mr. Shaw has 

 found that the cause of the death of cotton seedlings at 

 Cawnpore is Rhizoctonia and not a Fusarium wilt. It is 

 probable, however, that the cotton disease in the Central 

 Provinces, Berars and other parts of India is a true wilt, 

 and it is hoped to investigate this shortly. A gram dis- 

 ease resembling wilt, sent from the neighbourhood of 

 Peshawar, was found to be caused by Ascochyta Pisi and 

 not Fusarium. A supposed outbreak of indigo wilt which 

 caused a good deal of alarm in September, was shown to 

 be due to leaf-sucking insects. 



(/) Sugarcane diseases. — The field experiments with 

 red rot and Cephalosporiu7n disease were abandoned as 

 the plots became infected throughout, and were also at- 

 tacked by white-ants. Successful inoculations were ob- 

 tained with a fungus which causes a root disease in Madras 

 and has not previously been described. The Bombay De- 

 partment is following the recommendations of this section 

 in introducing healthy sets into some districts where red- 

 rot is severe. 



{g) Forest tree diseases. — These continue to occupy a 

 certain amount of time as there is no Mycologist attached 

 to the Forest Department. The chief work of the year 

 was the study by A. Hafiz Khan of the passage from root 

 to root below ground of Trametes Pini, the fungus which 

 causes heart rot of the blue pine. He published an account 

 of his investigation in the Indian Forester, October, 1910. 

 A serious disease of the Nahor [Mesua ferrea) has appear- 

 ed in Sibsagar and Tista Divisions. It is undoubtedly 

 caused by a fungus at the base of the tree, but we have 



