Effect of postharvest management on the microbial quality of potato (Solanum tuberosum L.) tubers

Abstract This experiment was conducted to appraise the role of the curing phytohormone treatment and storage method in the postharvest microbial decay of ware potatoes during storage. The study was designed as a Split-Split-Plot Design (SSPD) in which the curing period was placed in the main plot, and the storage method and the phytohormone were put in subplot and sub-sub-plot respectively. Each treatment was replicated three times to form a 4 × 3 × 3 factorial experiment. Each treatment consisted of 20 potato tubers out of which decayed samples were counted for the calculation of percentage rot loss and identification of the causal agent, which was done fortnightly until the end of the storage period of 12 weeks. Temperature, relative humidity, and wind velocity were monitored weekly. All data collected were subjected to analysis of variance (ANOVA) using the GenStat Discovery Edition statistical software package. Means that exhibited significant difference were separated using Duncan’s Multiple Range Test (DMTR) at p = 0.05 level of significance. The results of the analysis showed that the phytohormone levels had highly significant influence (p ≤ 0.01) on percentage rot loss. Although there was a significant interaction between the curing periods and phytohormone concentration, storage conditions (p ≤ 0.05) were observed throughout the storage period of 2–8 weeks. Fusarium solani, Rhizopus oryzae, and Aspergillus niger were implicated in the rotting of potato tubers.