Biology and Life Sciences

Biology and Life Sciences

Study on the Identification of Fungal Pathogen Causing Yam Rot in Lesser Yam (Dioscorea esculenta) in Batticaloa District, Sri Lanka

Pages: 4  ,  Volume: 4  ,  Issue: 1 , May   2018
Received: 13 May 2018  ,  Published: 19 May 2018
Views: 262  ,  Download: 122


# Author Name
1 K. Prasannath
2 S. Karunakaran


Dioscorea esculenta commonly known as the lesser yam is cultivated in Batticaloa district of Sri Lanka a small scale.  Pathogenic fungi reduce the quantity and quality of yam produced. Pathological investigations were carried out to find out the fungal organisms associated with yam rot of lesser yam. Eight pieces (2 mm in diameter) of the infected yam tissues were picked from the point of advancement of rot and inoculated on a solidified Potato Dextrose Agar (PDA) medium. Two replicates were made for each of the 4 yam tuber samples and the 8 plates were inoculated. The inoculated plates were incubated at room temperature (30°C) and observations were made daily for possible fungal growth. Sub-culturing was done to obtain pure cultures of the isolates. Cultural characteristics of the fungi were observed and recorded. The identification of the isolates was done by examining the isolates macroscopically and microscopically. The causative fungal pathogen was identified as Fusarium solani (Mart.) Sacc. based on the colony and microscopic characteristics of the pathogen. Fusarium solani produced white cream mycelia.  Macroconidia are three to four-septate, slightly curved, 28-42 x 4-6 µm. Microconidia are abundant, cylindrical to oval, one to two-celled, 8-16 x 2-4.5 µm. Pathogenicity test carried out confirmed this fungal species as the pathological agent of the lesser yam rot. The finding of the causal organism of the yam rot disease would be very useful in choosing effective control measures to extend the life span of yam in storage.



Amusa, N.A.,Adegbite, A.A., Mohammed, S. and Baiyewu, R.A. (2003). Yam disease and its management in Nigeria. African Journal of Biotechnology. 2: 497-502.

Barnet, H.L. and Barry, B.H. (1972). Illustrated Genera of Imperfect Fungi. 2nd Ed., Macmillan Publishing Coy. 886 Third avenue, New York. pp. 216.

Booth, C. (1971). The Genus Fusarium, Common Wealth Agric. Bureaux, Central Wales, Farnham Royal Bucks, England. pp. 81-167.

Ogundana, S.K., Naqvi, S.H.Z. and Ekundayo, J.A. (1970). Studies on soft rot yams in storage. Transactions of the British Mycological Society. 56: 73-80.

Okigbo, R.N. and Ikediugwu, F.E.O. (2000). Studies on biological control of post harvest rot of yam (Dioscorea sp.) with Trichoderma viride. Journal of Phytopathology. 148: 351-355.

Okigbo, R.N. (2004). A review of biological control methods of post harvest yam (Dioscorea sp.) in storage in south eastern Nigeria. KMITL Science and Technology Journal. 4: 207-215.

Osagie, A.U. (1992). The Yam Tuber in Storage. Post Harvest Research Unit, Nigeria. pp. 247.


Saikia, B., Rawat, J.S., Huitag and Das, A. (2011). An investigation on the taxonomy and ecology of the genus Dioscorea in Arunachal Pradesh, India. Journal of frontline Research in Arts and Science. 1: 44-53.