CEREALS 101 



available water supply. It is fortunate that the crop does 

 not suffer from any serious fungus attack. Dr. Butler, 

 Imperial Mycolo>gist to the Government of India, has 

 reported 1 rice bunt (Tilletia horrida, Tak.), Cercospora 

 oryzse, Miyake, (?) Entyloma sp., Eplcoccum hyalopes, 

 Miyake, Fusarium sp., Metaspkseria albescens, v. 

 Thuem., Nectria bolbophylli, P. Henn., Phoma gluma- 

 rum, Ell. and Trac., Pyrenochsete oryzse, Shirai, and 

 Septoria sp., as commonly found in the ears, stalks, or 

 leaves of rice in Lower Burma, but in no case doing any 

 material damage, being chiefly present on plants weakened 

 by insect attack. The latter constitutes the most serious 

 source of damage, and the various attacks of insects are 

 known collectively to Burmans as " gwabo." They are 

 mainly due to boring and cutting grubs of species of 

 Schoenobius and Nonagria. This insect attack, which 

 manifests itself in sterility and emptiness of the glumes, 

 is kept in check to a certain extent by the practice of 

 burning the stubble which is common in Lower Burma. 

 On only one occasion has the present writer seen a crop 

 completely destroyed by this cause, and that occurred in 

 the newly opened Mon-Canal area in Upper Burma. So 

 far attempts to obtain insect-resistant lines by selection 

 have not given any positive results. 



The very serious eel-worm disease of Bengal, known 

 as ufra, and due to a species of Tylenchus, has, for- 

 tunately, not yet made its appearance in Burma. 



The intra-varietal selection for "yield" forms one of 

 the most interesting and important aspects of rice im- 

 provement. At the Hmawbi Station the Svalof method 

 of comparing a large number of pure lines taken at 

 random, and selecting the heaviest yielding of these, has 

 been adopted. In the case of each variety to be improved 

 it was determined to begin the first year with 1,000 parent 

 ears selected at random, and planted out widely enough 

 to enable the habit of each individual plant to be seen. 

 At harvest a few of the largest and most vigorous plants 

 were first singled out, and then every tenth plant at 



1 " Diseases of Rice," Bulletin No. 34 of the Agricultural 

 Research Institute, Pusa, 1013. 



