Fungal Organisms Associated with Post-harvest Rot of Frafra Potatoes [Solenostemon rotundifolius (Poir.)] in Bongo-Soe, Upper East Region, Ghana

Abstract

Aims: The study aims to identifying the microorganisms associated with post-harvest rot of frafra potatoes in Bongo-soe, Upper east region of Ghana.
 Place and Duration of Study: Department of Horticulture and the Pathology laboratory of the Faculty of Agriculture, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana. The Solenostemon rotundifolius tubers were stored at the Horticulture Department laboratory whiles rot identification was carried out at the Pathology laboratory of the Faculty of Agriculture. The Tubers were stored from 2nd November, 2012 to 22nd March 2013.
 Methodology: Four hundred (400) tubers of black cultivar and four hundred (400) tubers of a brown cultivar of Solenostemon rotundifolius tubers showing visible signs of rot during the storage were collected. Pieces of diseased tissues from the margin of the necrotic collected and immersed in 10% commercial bleach solution for sterilisation, for one minute. These were then blotted dry and plated on Potato Dextrose Agar PDA. The plates were sealed with a cellotape until growth occurred.
 Results: The microorganisms identified to be responsible for causing rot in Solenostemon rotundifolius tubers were six in number. Colletotrichum gloeosporioides was identified to be responsible for 30.76% of rots observed, followed by Aspergillus niger, 23.07%, Curvularia lunata, 19.23%, Aspergillus flavus, 11.54%, Trichoderma sp and Penicillium sp both recorded 7.70% of rots observed. The percentage incidence of Aspergillus niger (15.38%), Curvularia lunata (11.54%) and Aspergillus flavus (7.69%) was higher in the black cultivar as compared with the brown cultivar which had percentage incidence of 7.69%, 7.69% and 3.85% respectively. Also, the percentage incidence of Colletotrichum gloeosporioides (15.38%) and Penicillium sp (3.85%) was the same in both the black and brown cultivars of Solenostemon rotundifolius tubers used in this study.
 Conclusion: The activities of the damaging microorganisms can be reduced by controlling mechanical injury during harvesting, transportation and storage of Solenostemon rotundifolius tubers should be prevented or reduced because they pave the way for tuber infection by the rot causing microorganisms.