Growth response of Botryodiplodia theobromae to some environmental factors and its implication on yam storage. – A. A., Markson, G. Omosun, B. E. Madunagu, A. C. Amadioha, S. E. Udo, E. J. Umana, U. Ekaluo
Successful yam storage has always been mitigated by activities of microorganisms. One of such is Botryodiplodia theobromae Pat. This fungus is a serious rot pathogen of many tuber crops. It causes dry rot of yam in the field and in storage. This study investigated some environmental factors that influence its growth in vitro. The factors considered were temperature and nutrient sources (carbon and nitrogen). Results of this study revealed that the growth of B. theobromae was supported within the temperature range of 200C and 300C. Below the lower limit, there was no initiation of growth and above the upper limit; there was significant decline in growth. At 400C, there was a total cessation of growth. Of the five carbon sources tested, sucrose gave the highest growth (110mg mycelial dry weight) while Carboxymethyl Cellulose (CMC) recorded the least mycelial dry weight of 70mg. Urea was the nitrogen source that supported the growth (100mg) of the test pathogen best, followed by potassium nitrate. Ammonium nitrate recorded the lowest growth value which did not differ from the 40mg weight recorded in the control experiment.