| Postharvest factors such as temperature, relative humidity, pH value, water content of the pericarp and several fungicides
on posthavest diseases of lychee fruits were investigated in this paper. The diameters of colony of Peronophythora litchii cultured on potato dextrose agar (PDA) were reduced in lower temperature as well as lower pH. Treating the fruit by boiling water combining with acid dipping and hence stored in lower relative humidity could reduce the occurring of P. litchii and Penicillium spp.. Treating the fruit by drying pericarp combining with acid dipping not only maintained the red colour of the pericarp but also suppressed Penicillium spp.,the main disease occurring in 0~4℃storage. The inhibition effects of seven fungicides to colony of P. litchii cultured on PDA were analyzed. Sportak, sporgon, shibaike and tecto totally inhibited the growth of colony at a concentration below 7 μg/L, and the EC50 were 0.1853, 0.3260, 0.4350, 0.8080 μg/L respectively. But aliene, sorbic acid and imazalil inhibited the growth of colony at a concentration above 450 μg/L, and the EC50 were 231.1, 401.9, 541.9 μg/L respectively. Drying pericarp combining with acid dipping or using the
fungicides such as sportak might serve as a postharvest treatment for cold storage of lychee fruits. |
