Susceptibility of different life stages of Callosobruchus maculatus and Callosobruchus chinensis to ECO2FUME gas and its impact on cowpea seeds quality

ECO2FUME gas is an alternative to toxic phosphine fumigant and as a quarantine treatment for the control of a particularly recalcitrant pest, Callosobruchus maculatus and Callosobruchus chinensis. This gas was used to fumigate stored cowpea piles under gas-proof sheets to assess its performance against different developmental stages of Callosobruchus maculatus and Callosobruchus chinensis. The mortality was determined on four developmental stages of C. maculatus and C. chinensis, employing ECO2FUME at different concentrations 25, 30, 40, and 50 g/m3 for 3-days. All stages of both insect species in packed cowpea stacks were completely controlled at 3-days when applied with an ECO2FUME application rate of 50 g/m3. Cases of pupae of C. maculatus and C. chinensis exhibit the highest resistance than other stages, with 78.2 and 73.93% mortality respectively, at 40 g/m3 after 3-days post-exposure to ECO2FUME. Suppression of F1 generation was obtained after fumigation with the same concentration (50 g/m3). Quality (in terms of cowpea germination) and all chemical constituents of cowpea seeds were non significantly (P≤0.05) affected by the fumigation concentration of 50 g/m3.

Susceptibility of different life stages of Callosobruchus maculatus and Callosobruchus chinensis to ECO2FUME gas and its impact on cowpea seeds quality

ECO2FUME® phosphine fumigant was used to fumigate stored cowpea piles under gas-proof sheets to assess its performance against different developmental stages of Callosobruchus maculatus and Callosobruchus chinensis. The mortality was determined on four developmental stages of C. maculatus and C. chinensis, employing ECO2FUME at different concentrations 25, 30, 40, and 50 g/m3 (2% PH3 and 98% CO2 by weight) for 3-days. All stages of both insect species in packed cowpea stacks were completely controlled at 3-days when applied with an ECO2FUME application rate of 50 g/m3. Cases of pupae of C. maculatus and C. chinensis exhibit the highest resistance than other stages, with 78.2 and 73.93% mortality respectively, at 40 g/m3 after 3-days post-exposure to ECO2FUME. Suppression of F1 generation was obtained after fumigation with the same concentration (50 g/m3). Quality (in terms of cowpea germination) and all chemical constituents of cowpea seeds were non significantly (P ≤ 0.05) affected by the fumigation concentration of 50 g/m3.

The Experimental Study on the Road Asphalt Fumes Suppressive Effect of SBS and Nano Calcium Carbonate

In order to study the fume suppressive effect of SBS and nano calcium carbonate， this paper studied the fume suppression laws of SBS and nano calcium carbonate， and carried out ratio test of SBS and nano calcium carbonate, and got the conclusions that: With the increasing adding level of SBS and nano calcium carbonate, the asphalt fume productive rate will reduce gradually and will reach a condition of stability. The adding level of 4% of SBS is a turning point. When less than 4%, the asphalt fume production rate decreased rapidly; and more than 4%, the asphalt fume production rate decreased slowly; when adding nano calcium carbonate at the level of 5%, the asphalt fume won’t decrease. The best ratio of SBS and nano calcium carbonate is 6% of SBS and 6% of nano calcium carbonate, with which asphalt fume reductive rate was up to 30%.