INSTITUTE AND COLLEGE, PUSA, FOR 1912-13. 59 



Northern India the parasite appears to die out rapidly in 

 the soil and there is not much danger from this source, 

 unless there is carelessness in allowing rotten canes to lie 

 on the fields after harvest. Infection by air-borne spores 

 through wounds in the stem, such as those caused by boring 

 insects, was found to be uncommon, though accepted as the 

 usual method in most other countries where the disease is 

 prevalent. The leaf scars at the joints, left after the leaves 

 are removed in stripping or wrapping the cane, are stated 

 by some observers to admit the parasite, but it was found 

 that this did not occur if the leaf had reached maturity 

 and came away readily. On the other hand the shoot and 

 root eyes at the joints can be infected and through the 

 latter, especially, the fungus has no difficulty in gaining 

 an entry into the cane pith. The most probable origin of 

 the infective matter was found to be a form of the fungus 

 which is parasitic on the midrib of the leaf, and which had 

 been overlooked by most observers. 



From these results, backed by field observations, it is 

 concluded that the most important precaution to be taken 

 against the disease is to select the setts used for planting, 

 so that only those with unreddened pith are used. The 

 effect of sett selection in keeping the disease from reaching 

 epidemic severity has been very satisfactory in several 

 Bihar estates and elsewhere, and it should be made a 

 routine practice. In very severe attacks sett selection may 

 fail, and it may be necessary to introduce new seed from 

 outside. Care must be taken at the same time to remove 

 early cases of the disease, in order to avoid risk of infec- 

 tion through the shoot and root eyes, and also to destroy 

 rotten canes and trash after harvest, so as to prevent in- 

 fection of the setts at or after the time of planting. 

 Finally it is pointed out that the " thin " canes, in which 

 India is so rich, are almost immune to the disease; that 

 the comparatively little damage caused by red rot in Java 

 may be due to the fact that many of the best Java canes 

 are the progeny of crosses between Indian thin canes and 

 the locally grown thick kinds; and that there is every 



