Influence of Fertilizer Application on Postharvest Storage of Two White yam (Dioscorea rotundata) Cultivars in Ghana

2018

English

Yam growers across major growing areas are being encouraged to increase tuber yield through the application of fertilizer at the recommended rates and periods. Ghana, the leading exporter of yam in Africa, is currently facing the problem of poor tuber storability. Some actors along the food value chain attribute most storage rots to the application of fertilizer by farmers. This study was conducted to investigate in to the claim that fertilizer application has an effect on the shelf life of white yam tubers. Four fertilizer application models were tested on two white yam cultivars, Serwa and TDr95/19177. No fertilizer application served as the control experiment. Healthy- looking white yam tubers of the two cultivars were randomly selected from a fertilizer application trial at Ejura-Sekyedumasi District in Ashanti Region of Ghana and storage rot experiment conducted at CSIR-CRI(onstation) between January and July, 2015.The experimental design was a Split plot design with three replications. The main plot represented the two cultivars whilst the sub-plot was the fertilizer models. Initial parameters taken were tuber weight, yield and moisture content. Temperature and relative humidity were periodically recorded. Rot assessment were done at 3rd, 4th, 5th and 6th months of storage. Rot analysis parameters taken were tuber weight, number of rotten tubers, rot initiation point, rot type and associated pathogens. Percent incidence and severity were determined and used for the analysis and interpretations. Severity data was subjected to statistical analysis using the Genstat statistical package 9.2, after the results was transformed using the square root transformation. Major fungi identified from rotten tissues over the period were Lasiodiplodia the obromae, Fusarium oxysporum, Penicilliumsp., Rhizopussp., Aspergillus flavus. Fifty-four percent of rotten tubers were the dry rot type. There were similarities in the incidence of rot among all treatments. There was no significant difference in terms of rot severity among the fertilizer application models as well as the control. However, varietal differences and tuber sizes were key factors identified as having effect on storage rots. Further studies on commercial white yam varieties such as Pona and Dente need to be conducted to evaluate the influence of fertilizer application on their shelf lives

Aidoo, A. K.; Danquah, E. O.; Frimpong, F.; Lamptey, J. N. L.; Ennin, S. A.; Appiah-Kubi, Z.