Description

ABSTRACT

Postharvest rot pathogens constitute a major threat to the enormous potential of yam tuber (Dioscorea species) in enhancing food security and safety. The control of yam rot in storage has been an object of research for decades especially in Africa, Asia and certain parts of Europe where yam is produced in large quantities. Various control methods ranging from the use of synthetic chemical, bio-control agents, curing, nanobiotechnology and the use of plant extracts; have been explored to tackle the menace of post-harvest rot of yam tubers. It was discovered that even though most researchers are discouraging the use of synthetic chemicals because of the associated environmental hazards and the inducement of resistance in targeted pathogens, it is still the most effective method in controlling the rot of yam tuber in storage due to its immediate action especially when compared to the use of biological control agents which often require some days before its effect is noticed. It is necessary that curing precedes any of the control methods adopted coupled with an appropriate storage structure. There is an urgent need to understand the mode of action of all the plant extracts proven by research to possess anti-rot properties so as to enhance its applicability. Standardization of plant extracts will also go a long way in enhancing their efficacy, especially at various concentrations; as it has been reported in the use of synthetic chemicals. Nanobiotechnology should be explored for possible solutions in addressing the strain of rot pathogens that have become resistant to synthetic chemicals. This review provides a critical analysis of all the control methods listed above, their strengths and weaknesses, the effect of storage techniques and structures on the microbial deterioration of yam while giving insight into ways of maximizing and improving them.

Keywords: Yam, rot, control, storage, microbial deterioration and postharvest