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Role of environmental factors and handling of some vegetables in degradation of organophosphorus
pesticides residues
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Abstract: Potato and tomato plants were treated with chlorpyrifos-methyl and pirimiphos-methyl insecticides under the normal field conditions at the rate of 250 and 750 grams active ingredient per feddan respectively. Pirimiphos-methyl insecticide had the highest initial deposits. The highest concentration of initial deposits was found on and in tomato fruits while the lowest were that on and in potato tubers. Tomato fruits exposed directly to spraying solution whereas potato tubers were buried in the soil. Potato tubers were devoid of any detectable amounts of both insecticides 14 days after treatment while tomato fruits collected 21 days after treatment were contaminated with 0.13 and 0.84 mg/kg of chlorpyrifos-methyl and pirimiphos-methyl respectively. The PHI,s are 14 and 15 days for tomato fruits while they are 1 and 2 days for potato tubers after treatment with chlorpyrifos-methyl and pirimiphos-methyl.
Treatment of potato tubers in warehouse with the two tested insecticides with the mentioned rates showed that the half-life time of chlorpyrifos-methyl was highest (5.4 weeks) than that of pirimiphos-methyl (3.5 weeks).
Sunlight was more effective than UV-rays in accelerating the photodecomposition of chlorpyrifos-methyl and pirimiphos-methyl residues. The intervals between successive sprays of both insecticides should be shorter at high temperature and vice versa.
Peeling of potato tubers gave 97.13 and 95.25% loss of chlorpyrifos-methyl and pirimiphos-methyl residues respectively from contaminated potato tubers. Boiling with hot water for 30 min. removed 83.07 and 91.56% of residues of the tested insecticides respectively. Washing with tap water removed 43.03% of chlorpyrifos-methyl from contaminated tomato fruits while soaking in vinegar gave 34.1% loss of pirimiphos-methyl from tomato fruits.
Key words: Potato tubers, tomato fruits, chlorpyrifos-methyl, pirimiphos-methyl, residues, pre harvest intervals, warehouse, photodecomposition, UV-rays, temperature, sunlight, home processing’s.
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| Publication year |
2005
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| Availability location |
7 شارع نادى الصيد - الدقى - الجيزة(المعمل المركزى لتحليل متبقيات المبيدات والعناصر الثقيلة فى الأغذية)
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| Availability number |
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| Organization Name |
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| Country |
Egypt
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| Department |
Pesticides Residue Analysis
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| Author(s) from ARC |
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| Agris Categories |
Pests of plants
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| Proposed Agrovoc |
Plants, Effect of insecticides;Plants -- Diseases and pests;
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| Publication Type |
PhD Thesis
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