58 REPORT OF THE AGRICULTURAL RESEARCH 



easily be overlooked, as its chief effects are to cause exces- 

 sive late tillering of the plant and partial sterility of the 

 ear. Its further investigation was taken up by Mr. Shaw, 

 who has established the parasitism of the fungus and 

 studied its behaviour in artificial culture. The disease is 

 probably one of the causes of the condition known in Burma 

 as gwa-bo, in which an undue proportion of the ears are 

 light or partially sterile and which is said to represent a 

 very great aggregate loss. I found on local examination 

 that most of the loss was attributable to insect pests, chiefly 

 borers, and that fungus injury was probably too slight to 

 be of economic significance. Mr. Shaw has prepared an 

 account of his investigation, which is in the press as a 

 Memoir. 



(2) Sugarcane diseases. — The " red rot " of sugarcane 

 (caused by C olletotrichum falcatum Went.), which is the 

 worst fungus disease of this crop in India, has been under 

 study at Pusa for a number of years. Various difficul- 

 ties which were met with have delayed the writing up of 

 the results, but sufficient information has now been ob- 

 tained to justify publication. A Memoir, prepared jointly 

 by myself and A. Hafiz Khan, Third Assistant, to contain 

 the results of experimental work since 1906, has been sub- 

 mitted for publication. The experiments have been chiefly 

 directed to obtain information as regards methods of infec- 

 tion. It has been securely established that the most com- 

 mon method in Northern India is by the planting of 

 infected setts from a previously diseased crop, a method 

 that has been recently controverted in Louisiana and the 

 West Indies. The failure of sett selection which has been 

 observed on several occasions, has been shown to be due to 

 the presence, in severely diseased crops, of a percentage of 

 infected canes which do not show the characteristic warn- 

 ing symptom of reddening in the pith. In attacks of 

 ordinary severity this percentage is negligible, but in severe 

 epidemics it is advisable to avoid the use of any cane from 

 the diseased crop for seed. It has been further shown 

 that sound setts may be infected after planting, though in 



