Microbial, thermal and photodegradation of cadusafos and carbofuran pesticides | ||
Journal of Pest Control and Environmental Sciences | ||
Volume 14, Issue 2, December 2006, Pages 107-130 PDF (217.31 K) | ||
Document Type: Original Article | ||
DOI: 10.21608/jpces.2006.460728 | ||
Authors | ||
F. I. Eissa* 1; Hend A. Mahmoud2; N. A. Zidan3; E. B. A. Belal4 | ||
1Environment and Bioagric. Dept., Fac. of Agric., Cairo, Al-Azhar Univ. | ||
2Central Agricultural Pesticides Laboratory, Agricultural Research center, Dokki, Giza. | ||
3Pesticides Dept., Fac. of Agric., Kafr El-Sheikh Univ. | ||
4Agric. Botany Dept., (Agric. Microbiology), Fac. of Agric., Kafr El-Sheikh Univ. | ||
Abstract | ||
Experiments were conducted to investigate the influence of microbial activity, different temperatures, ultraviolet (UV) rays and direct sunlight on the rate of degradation of cadusafos and carbofuran, which are widely used in Egypt as nematicides and insecticides. Microorganisms capable of degrading the two tested pesticides were isolated, using an enrichment technique, and identified as Pseudomonas sp., Pleurotus sp. and Phanerochaete chrysosporium. Pseudomonas sp. was isolated from soil, while Pleurotus sp. and P. chrysosporium were isolated from mature compost previously treated with the two tested pesticides. Cadusafos half-life values in a liquid mineral medium amended with Pseudomonas sp., Pleurotus sp. and P. chrysosporium were 29.77, 91.47 and 24.82 days, respectively. On the other hand, carbofuran half-life values in the same medium that amended with the aforementioned microbial strains were 12.7, 16.9 and 17.7 days, consecutively. Thus, P. chrysosporium was the most active strain in cadusafos biodegradation and Pseudomonas sp. was the most effective strain to degrade carbofuran. Generally, carbofuran was highly biodegradable than cadusafos. Data concerning the role of temperature indicated that increasing half-life values were observed with decreasing the temperature, where the recorded half-life values for cadusafos and carbofuran were 1056.18 & 499.10 hrs at 25 ˚C; 472.54 & 253.45 hrs at 35 ˚C and 395.36 & 207 hrs at 45 ˚C, respectively. As regards UV-rays, results revealed that cadusafos photo-decomposed faster than carbofuran, since their half life values were 7.33 and 16.11 hrs, successively. As respects sunlight, data demonstrated that half-life values of cadusafos and carbofuran were 5.79 and 3.89 hrs, consecutively. It can be observed that sunlight is found to be more effective than UV-rays in accelerating the photodecomposition of the tested pesticides. Perusal of the early mentioned results clearly showed that degradation rate of the two tested pesticides varied according to their chemical structure, factor causing degradation and time of exposure. | ||
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