Efficiency of Cold Plasma and Microwave Power on Different Stages of Callosobruchus maculatus

Abstract

This study investigated the effectiveness of cold plasma (CP) technology and microwave (MW) treatments on various stages of Callosobruchus maculatus. Beetle stages were exposed to three voltage levels of CP (150, 200 and 250V) for seven different exposure periods (1-20 minutes) and MW at two power levels (100 and 180W) for seven exposure periods (0.5-10 minutes). The results obtained showed that the effects of CP and MW on the beetle stages were independent of voltage, power level, and exposure time. For CP, mortality rates of C. maculatus stages were 51.2, 55.0, 56.9 and 50.5% after 5 minutes of exposure at 150V for adults, eggs, larvae, and pupae, respectively. Complete kill of all stages was achieved after 5 minutes of exposure at 250V. For MW, at 100W power level and 1 minute of exposure, mortality rates were 71.0, 67.7, 75.5 and 56.7% for the above-mentioned stages, respectively. Complete kill of all stages was achieved after 6 minutes of exposure at 180W. The larval stage was the most sensitive to both CP and MW, while the pupal stage was the most tolerant. Additionally, exposure to CP voltages enhanced cowpea seed germination, whereas microwave treatment decreased germination by 24%. CP voltages also reduced the cooking time of cowpea seeds.

Keywords:

Cold plasma, microwave, Callosobruchus maculatus, germination.