l2ri Miittliim.oi.Y AMI l'.\l!.\SITI.s.M (IT KlIIZOCTONIA. 



(iromid mil. — In llic licLnniiiiii,' of lltll. while cxaiiiiniii'; sonic 

 soods of ground mit. it wns noticed that in a huge lunnlx-r of sccch^ 

 the pericarp had a mottled aj)pearance. showing discoloured ])atche.s 

 (PI. IV. Figs. 3. 4). Examination of these dark areas revealed, in 

 some cases, byplia?, like those of Rhizcctonia, ranufying in the tis- 

 sues ; in other cases there was no apparent cause for the discolora- 

 tion. Not only were hyplia? found in the pericarp but they were 

 also sometimes present within the embryo. Portions of the pericar]) 

 of seeds, and, in some cases, entire seeds, were incubated in sterile 

 ])etri dishes and gave a vigorous growth of hyphit" of Rliizvdoniu 

 which was sub-cultured on agar medium E. 



A further e.xpeiiment was then j^M-fonned in which four seeds 

 were sterilised by soaking in 2'5"o Formalin for five minutes, and 

 sown in sterile drying towers containing Knop"s solution, a method 

 first used V^y Ward(29). Of these four seeds only one germinated, 

 the remaining three died and became covered with an abundant 

 growth of livpha- and small black scjeiotia, which were sub-cultured 

 on agar medium K ; the cultures obtained in this way resenil)led 

 tho.se of the llhizoctoHta of cotton and jute. Latci- in the year, in 

 August, an examination of the ground mit crop on Pusa Farm show- 

 ed that many plants were infected with Rhizcctonia. The upper 

 portion of infected plants appears brown and witlicrcd (PI. 111. Kig. 

 3), while at the ground level the .stem is a dark lilack colour : in this 

 portion hyphse and sclerotia are particularly abundant. Specimens 

 of groundnut attacked by Rhizactcnia were also received from Surat : 

 in these the small black sclerotia were abundant, occurring not only 

 on stems but also on leaves. A small piece of one of these blackened 

 stems was incubated and gave a culture which resembled in all res- 

 pects that obtained from the hyphse in the seeds. In this connec- 

 tion it may be noted here that specimens of diseased sesame from 

 Surat were found to be infected with Rhizvdon'.a in the same way 

 as the ground nut, the external symptoms of the disease ajid the 

 cultural cbaracttrs of the fungi's ixactly icstmbling those detailed 

 ubcve. 



