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Effects of 2,4-D(2,4-dichlorophenoxy acetic acid) and Dichlorvos(2,2-dichlorovinyl dimenthyl phosphate DDVP) were investigated on soil microbial population in a 4 weeks experiment. Soil samples were serially diluted and inoculated using pour plate method on different medium and incubated at 37°C for 24 and 48 hrs for enumeration of microbial diversity, colonies that appeared on plates were counted. At pre-application of 2,4-D, bacteria had the highest population (9.5x107 Cfu), followed by fungi (7.5x105 Cfu ), actinomycetes (1.6x106 Cfu) and protozoa (1.1x103 Cfu). Likewise, the pre-application of DDVP represents the population count of microorganisms in the following manner: Bacteria (8.0x107 Cfu)>fungi (5.1x105 Cfu)>actinomycetes (1.0x106 Cfu)> protozoa (1.0x103 Cfu)f The post-application of 2,4-D and DDVP also had the similar pattern of population count. With percentage difference on each of the microbial counts, 2,4-D of bacteria, fungi, actinomycetes and protozoa (99.5%, 95.3%, 99.9% and 86.0% respectively), DDVP percentage difference (99.2%, 99.4%, 99.3% and 98.6% respectively). Application of these pesticides at recommended rates was followed by the general decline in microbial counts. Therefore, the pesticides had toxic effects on microorganisms which may be beneficial to cultivated plants.
Obrycki JJ, Harwood JD, Kring TJ, O’Neil RJ. Aphidophagy by coccinellidae: Application of biological control in agroecosystems. Biol. Control. 2009;51(2):244–254.
Fanti Alessandro, et al. Nonlinear analysis of soil microwave heating: Application to agricultural soils disinfection. IEEE Journal on Multiscale and Multiphysics Computational Techniques. 2017;2:105-114.
Cycoń M, Piotrowska-Seget Z, Kaczyńska A, Kozdrój J. Microbiological characteristics of a sandy loam soil exposed to tebuconazole and λ-cyhalothrin under laboratory conditions. Ecotoxicology. 2006;15(8):639-646.
Singh B, Singh BP, Cowie AL. Characterisation and evaluation of biochars for their application as a soil amendment. Soil Research. 2010;48(7):516-525.
Cycoń M, Piotrowska-Seget Z, Kozdrój J. Responses of indigenous microorganisms to a fungicidal mixture of mancozeb and dimethomorph added to sandy soils. International Biodeterioration & Biodegradation. 2010;64(4):316-323.
Subhani A, El-Ghamry AM, Changyong H, Jianming X. Effects of pesticides (Herbicides) on soil microbial biomass-A review. Pakistan Journal of Biological Sciences. 2000;3(5):705-7O9.
Ashton FM, Crafts AS. Mode of action of herbicides. New York; John Wiley. 1973;504.
Foster RK, McKercher RB. Laboratory incubation studies of chlorophenoxyacetic acids in chernozemic soils. Soil Biol. Biochem. 1973;5:333-337.
Hemmett RB, Faust SD. Biodegration kinetics of 2,4-dichlorophenoxy acetic acid by aquatic microorganisms. Residue Rev. 1969;29:191-207.
Hodges L. Environmental pollution. New York, NY: Holt, Rinehart and Winston, Inc. 1973;184.
Kurle K. Do soils suffer from pesticides? Pesticide Chemistry. Proceedings 7th International Congress of Pesticide Chemistry. 1991;1.
Lotti M. Clinical toxicology of anti-cholinesterase agents in humans. In: Krieger R, (Education). Handbook of Pesticide Toxicology. Volume 2. Agents, 2nd Education Academic Press, San Diego. 2001;1043-1085.
Saad O. A Vez dos herbicide. 2. Ed. Sao Paulo: Nobel. 1978;267.
Takano HK, et al. Efeito da adicao do 2,4-D ao glyphosate para o controle de especies de plantasdaninhas de diffcilcontrole. Revista Bras. Herbicides. 2013;12(1):1-13.
Oh K, Tuovinien OH. Bacterial degradation of phenoxy herbicide mixture 2,4-D and MCPP. Bull Environment. Contam. Toxicol. 1999;47:222-229.
Smith AE, Aubin. Loss of enhanced biodegradation of 2,4-D and MCPA in a field soil following cessation of repeated herbicide applications. Bull. Environ. Contam. Toxicol. 1994;53:7-11.
Shaw LJ, Burns RG. Biodegradation of 2,4-D in a noncontaminated grassland soil profile. J. Environ. Qual. 1998;27:1464-1471.