Abstract:

During storage of ginger, the occurrence of Pnyxia scabiei Hopkins can cause serious damage, leading to huge
economic losses. In this study, we examined the effect of controlled atmospheres with varying O2/CO2 levels (100% O2,
95% O2 + 5% CO2, 90% O2 + 10% CO2, and 85% O2 + 15% CO2) on the physiological metabolism, growth and development,
and mortality rate of P. scabiei Hopkins. The natural atmosphere was used as control. Physiological indexes of P. scabiei
Hopkins were measured at regular intervals at 20 ℃ and 85%–95% humidity. The results showed that the controlled
atmospheres, especially 95% O2 + 5% CO2, significantly reduced enzyme activities in P. scabiei Hopkins. After 60 h,
compared to the control group, the activities of protease, polyphenol oxidase (PPO), acetylcholinesterase (AChE),
carboxylesterase (CarE) and glutathione-S-transferase (GSTS) were reduced by 14.7%, 53.59%, 72.52%, 80.3% and 61.63%,
respectively, and the mortality rate (97.83%) was increased by 96.22%. The effect of 90% O2 + 10% CO2 was slightly
weaker, but showing no significant difference from the 95% O2 + 5% CO2 treatment. This study demonstrates that the O2/CO2
controlled atmospheres can be a potential control measure for P. scabiei Hopkins during ginger storage.

Key words: ginger, Pnyxia scabiei Hopkins, O2/CO2 controlled atmosphere, high oxygen, high carbon dioxide, mortality