162 HED ROT OF SUGARCANE. 



in every node and this was less intense as a rule. The hitter cuttings 

 had generally a white strand along the side from which the shoots 

 arose. Of 30 inoculated cuttings 8 growing points were found 

 to become diseased ; a similar condition was observed in two controls. 

 In one inoculated shoot Colletotrichum was identified. The control 

 shoots were more numerous, weighed more and were generally more 

 healthy in appearance than those from inoculated cuttings. In 

 Barbados, 40 setts each of White Transparent, Bourbon, B 147 and 

 B 376 were inoculated before planting, a parallel set being grown 

 as controls. The inoculations took, but growth within the setts 

 was slight, the discoloration being only visible for about 2 by l 

 inch round the wound after 6 weeks. There was no definite sign of 

 penetration into the buds at this period. After three months theie 

 were 7 withered shoots in the controls and 15 in. the inoculated 

 cane. Colletotrichum could not be found in the diseased growing 

 tips. The healthy shoots were cut oH' from the inoculated setts by 

 the formation of a woody partition. The authors conclude tliat 

 the fungus is a facultative wound parasite, infecting chiefly through 

 wounds such as borer holes, and not carried into the young slioots 

 from infected setts. 



Since it is fully established that stem wounds allow of arti- 

 ficial infection, experiments were carried out witli a view to ascer- 

 tain how far tliis is a conuuon origin of the disease in nature. Pi'ac- 

 ticallv the only wounds wliich open a passage direct to the pith 

 aie those due to the various stem borers so commonly found in cane. 

 These wounds were tested for (\)lh'tofrirJnnn on several occasions. 



In Novend)er, 1907. when red lol was pre\alent at I'nsa, six 

 canes with })orer holes were examined hy cutting out aseptically a 

 slab to include the reddened area always fonnd in the immediate 

 vieinitv of the hole. ( )n incubation none gave Collcfofilc/nnn. 

 In the same month the following yea i' the experiment was repeated 

 with 9 bored canes. The result was again negative. in.Iamiary, 

 1909, 12 bored canes were similarly examined at Samalkota, with the 

 same result. In addition we have exannned by sectioning the neigh- 

 bourhood of the holes in bored canes on many occasions when the 



