Occurrence of storage rot disease of kolanut across the kola growing belt of Nigeria

Abstract

Studies were carried out at the Cocoa Research Institute, Ibadan, Nigeria to determine the frequency of
occurrence of storage rot disease caused principally by Botrodiplodia theobromae and Fusarium pallidoroseumon the
two edible Cola species, Cola nitida and Cola acuminata. Several samples of healthy and diseased kolanuts were
randomly collected from fourteen locations across the kola growing belt of Nigeria which is predominantly rain forest.
Samples were surface dis-infected and placed on acidified potato dextrose agar at 25°C for 7 – 10 days.
Botryodiplodia theobromae, Fusarium pallidoroseum Aspergillus, Penicillium, Mucor and Chlamydomyces spp
were the common fungal genera isolated from both C. nitida and C. acuminata nuts. The mean frequency of
occurrence of B. theobromae and F. pallidoroseum were 0.47 and 0.34 respectively on C. nitida while it was 0.20 and
0.34 respectively on C. acuminata. Storage rot disease was found to be present in all the locations where samples of
kolanut were collected. Similarly, the mean frequency of occurrence of B. theobrome and F. pallidoroseum were 0.69
and 0.53 respectively on kola pods when compared with the occurrence of other fungal genera. Whereas Peacilomyces
and Mucor spp were isolated on C. nitida nut they were not isolated from C. acuminata nut. This present study
confirmed the wide spread of the kolanut storage rot disease across the rain forest zone of Nigeria.
Key Words: Kolanut (Cola sp.); Storage rot disease; Botrodiplodia theobromae; Fusarium pallidoroseumon.