Effect of temperature and relative humidity on efficacy of diatomaceous earth (Protect-It) on mortality of rice weevil, Sitophilus oryzae.

摘要

The effect of diatomite (DE) on mortality of adults of Sitophilus oryzae clearly revealed the importance of temperature and relative humidity (RH). A 100% mortality was recorded at combinations of highest temperature (35 degrees C) with all the 4 RH of 30, 50, 70 and 90% and at 30 degrees C in only 30, 50 and 70% RH combinations, while at 25 degrees C at only 2 lower RH (30 and 50%) and at lowest temperature 20 degrees C in only with lowest RH (30%) combinations. However, in other combinations, mortality ranged from 75 to 97%. A very similar trend was observed in 2 releases. Sorghum seed germination ranged from 38 to 88.5% in different concentrations of temperature and RH tested. The least germination was recorded in the untreated control (40%). No seed damage was recorded in even at highest RH (90%) at both the highest temperature (30 and 35 degrees C). More seed damage was noticed in the untreated control.