Abstract: Two insecticides were applied separately to the soil at 4000 and 8000 ppm for thiodan® and 6000 and 12000 ppm for karate®, respectively. Their effects were investigated at 0, 14, 21, 28, 35, 42 and 49 Days after Treatment (DAT) on the population of bacteria, fungi, actinomycetes and protozoa in the soil. The microbial population was estimated using the standard dilution plate technique. The two insecticides investigated at both rates of application significantly (p 0.05) reduced the fungi, actinomycetes and protozoa population in the soil. Whereas the bacteria population was significantly (p 0.05) increased. Thiodan at the rate of 8000 ppm gave significantly (p 0.05) lowest population of fungi in the soil compared to actinomycetes and protozoa population. A progressive increase in the soil microbial population for various insecticidal treatments in the order of 49DAT > 35DAT >28DAT > 21DAT > 14DAT > 0DAT was observed. The significance of thiodan and karate insecticide at two different rates of application on the soil microbial population is herein discussed.
T.A. Adebayo , O.A. Ojo and O.A. Olaniran , 2007. Effect of Two Insecticides Karate(R) and Thiodan(R) on Population Dynamics of Four Different Soil Microorganism . Research Journal of Biological Sciences, 2: 557-560.