

Till: AGRICULTURAL NEWS. 



•lii.v 17, 1915. 



FUNGUS NOTES. 



THE INTERNAL DISEASE OF COTTON 

 BOLLS. 



91 I. Mr. \V. I; 

 the Botanic 8 



'truing tin e pi bacterial blight due to 



Bad 1 1 urn m ■ la nd, submitted specim 



of what appeared to hin i ' inct boll affection. 



I'. \\ Soul h, M \ co! I lepartment, examii 



these and noticed i ority of the bolls the association 



oi discoloured lint with proliferations ol the inside tissues of 



tin n ■ of t In nn ire dec ■ 



ecimens. II istence of the proliferations 



;.- si ggesl ive "' dama i ; insei It may be 



■ i b proliferations in 

 • :ked by plant bugs appears to have ! " 



first described and figured by Df. A. \\ . Morrill (United 



States Departinei B au of Enl 



54, I9i ' ' i. In the same month 



ison called { occurrence on two estates of 



large numbers of internally discoloured bolls. In respo 

 to a query b) South he expressed the opinion that cott >n 

 stainers were not pn ?ali d1 on these fields at the time of the 

 observations. Further reference was made to the affection 

 in the Report of the Montserrat Botanic Station For 1911-1 2, 

 and in th report the cotton stainer was said to !»■ 



incn ice as 6ton pest, so that many 



planters had found it necessary to adopt means of < trol. 



In December 1913, Robson's attention was a, 

 called to the ■;■■ the presence ol discoloured lint in 



the second crop of t] ! I led I hi occui i 



of co egarded the apparent disproportion 



between theii served numbers and the amount of the 



injury as telling a thi ted i sion. Ma 



collected at tliis ! i nined by the present writer, 



who found the general appearance! of the affected bolls to 

 coii i except that of abnormal sh : 



with the description given bj Lewton-Brain. Proliferations, 

 as described by Morrill and mentioned by South, were found 

 to be general in the affected bolls, and it seemed clear in 

 some that the rot had commenced from these. 



i ibed by Lewton Brain, were not prea 

 but in all cases hyp] round growing amongst 



the lint and in the lumina of the fibres. Spores of 

 one type were present to a greater or lesser extent in 

 all the i samples, but their conm i 



ild not be out. They an- one-celled, elongate, 



straight or more usuall} slightly ereacentic, acuminati 



;0 by 2 microi They oi 



in irregular tufts or clumj I adhere closelj 



At' i] were un 



cessful. 



In January 1914, Rob tor confirmed i i mnt 



nt t he rapidity with w I ion devi lopi i ling 



discoloured l»>lls to > 



wei I free. ] otes the 



.mil 



sakell ' : ! in t\ pes, 1 . itei I ■ added 



to thi~ li I i he Mont set r it \\ ild ci >l < nial 



■ 

 which he I 



In \l;i\ 1914, fivi ntal pints were started it 



Monl serraf on line rj bj the present writer I 



■ sumption that a definite fungous infection was con- 

 cerned. Three plots of some fil h were p] 

 in close pro two of them with tained 

 bolls, i irrosive sublin 



ited in tin : fr Bat 



the affection is not known to occur. There « 

 material din Its of these tin lo The 



first crop, picl ">epte I a peri enl 



I bolls which varii 1 irn gularly from 10 to 



ill i Wit h the beginning of I he 'si nd pii 



ou November II, the number had fallen to i ro o 

 plot (tit: \ bolls pel plot i very 



low throughout the month. InD pidand regular 



rise '■ mrhood of 7i 



cent, towards the end of the month, and maintained in the 

 - and nineties in the two January pickings which 

 concluded the experiment. trth plot, n om the 



I id with Barba los seed on land not recently 

 in cotton. No staining whatever occurred during 8 

 t tctobet , and Ni >\ i ruber, bul fi im early 1 1 i inward 



i he plot shared in the rapid ris al the same 



time mi the prei iously defect ibed plots. 



During the course of tl riments Robson bet 



convinced that t 

 a neci int of the affection. 



He gives as his reasons for this view: (a) the absence of 



Section in situations where cotton - 1 ire not found, 



(b) the high percentage of afl level cotton 



are plentiful, (c) the issoi n of 



proliferations on the inside of the carpels with the staining, 

 and (d) the occurrence, in bolls in which staining i 

 commencing, of wa d taken as indii 



punctures such as would be cause. I \>\ the setae of tin 



The history of the fifth of the plots above mentioned i- 

 interesting in this connexion. It was planted with Barbados 

 seed on land where cotton grown the previous season had 

 been heavily stained, and the rest of which was now in sugar 

 cane. During September and Octobei staining was recorded 

 in two out of five examinations, namely 5 per cent, on 

 ruber 12, I per cent, on October 12. Whether stainers 

 were present on these occasions was not n I There 



was no .staining during November. On tin 27th of that 

 month about 100 stainer bugs were artificially intro 

 duced. Affected bolls occurred ] examination 



during l> mber and January, varying irregularly from 



■ ' to I : ' i ient. The Imgs did not seem to find the 



situati ion ■■ trial and are reported to have all disappeared 



by tin I i signifii mt point is that 



while On all theother plots, which remained infested with 



the ie to : reached 50 per cent, by 



t he middle i t I tecembfir and culminated at the 

 observation in J nuafj al 92, 94,84, and To pei 



tively, the amount on the fifth plotdid not go above 

 15 and ended at operant. Examples of the affected bolls 

 from these plots were exi y the writer. In a 



' ion ot ria were dominant, iii the real 



,i hint in the stained lint. The 

 seen in the previous year were not found, which m ly or may 



I l f the 



to t he id 



When h - the cause uf the 



affectio I I to imitate their action by pricking about 



twenty bolls with a needle. Six diys latei 



