Effects of Extracts of Some Botanicals against Three Species of Fungi Isolated from Cocoa (Theobroma cacoa L.) Pods

Cocoa is an important cash crop in the tropics and sub-tropics. However, its production is reported to be immensely constrained due to black pod disease caused by fungal agents. This study evaluated in vitro the efficacy of ethanolic and aqueous extacts of purging nuts (Jatropha curcas L.), bitter leaf (Vernoma amygdalina), lemon grass (Cymbopogon  citratus), pods of guinea pepper (Xylopia aethropica), seeds of black pepper (Piper guinense), rhizomes of ginger (Zingiber officinale) and stem ash of Acioa bacteri at varying concentrations (0, 10, 20, 30, 40 and 50%) against the  fungi associated with pod rot of cocoa. Results obtained from the study showed that the ethanolic extracts of black pepper (Piper guinense), wood ash (Acioa bacteri) and ginger roots (Zingiber officinale) strongly inhibited the radial growth of Phytophthora megakarya and Colletotichum ignotum by (84-100%). While PDA media modified with warm water extract of black pepper (Piper guinense), bitter leaf (V. amygdalina), wood ash (A. bacteri) and ginger (Z. officinale) roots showed varying levels of inhibition (71-100%) of the radial growth of three test fungi. Of all the extracts, F. decemcellulare was only sensitive to water extracts of V. amygdalina recording (84-100%) inhibition. However, irrespective of concentration and extracting solvent Purging nut (Jathpha curcas) A. aethiopica and C. citratus were not effective in minimizing the growth of the assayed fungi in culture. Hence, extracts of ginger, black pepper, bitter leaf and A. bacteri can be exploited for control of pod rot of cocoa caused by P.megakarya and C. ignotum.   Keywords: Cocoa, Pod rot, Plant extracts, Colletotrichum ignotum, Phytothtora megakarya