النشر العلمي

  • الخلاوي ودورها في نشر التعليم الديني في السودان

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published in مؤتمر اللغة و الهوية في افريقيا

  • الإمام الغزالي و أثره على الفكر الإنساني

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published in جامعة الخرطوم

  • DETERMINATION OF INSECTICIDE RESIDUES IN OKRA FRUIT WASH USING MOSQUITO LARVAE (Anopheles arabiensis Patton) AS BIO-INDICATOR

A study was conducted to determine insecticide residues in okra (Abelmoschus esculentus L) fruits by using mosquito (Anopheles arabiensis Patton) larvae 3rd or early 4th instar as a bio-indicator a tool instead of high technology and costly analytical equipment. Mortality was evaluated by taking 10 larvae/replicate (3 replicates/ concentration) and each experiment was repeated thrice to obtain the Probit model used later in the field study to calculate the residues. The insecticide residues in tape water fruit wash of okra fruits collected from the field were investigated by using the mosquito larvae from day 1 to day 10 after insecticide application. The results were subjected to the equation of the regression line for each insecticide used, as the Probit model, to calculate the concentration of these insecticides in okra fruits collected from the sprayed field. The residues were measured from 250 g and 1 kg of fruits as mg/g okra fruit. Malathion and cypermethrin residues in the 0.25 kg batches and 1 kg batches were found below the Acceptable Daily Intake (ADI) of 0.02mg/kg body weight and 0.05mg/kg body weight, respectively, while imidacloprid was above the ADI (0.06mg/kg body weight) in day 1 - day 6, but was equal to ADI in day 2 for the 0.25 kg batches, and below the ADI for the rest of the days. Regarding the 1 kg batches, the imidacloprid was found above the ADI in days 1, 2, 3, and 4, equal to the ADI in days 5 and 6, and below ADI in 7, 8, 9, and 10 days.  Key words: Bioindicator, Cypermethrin, Imidacloprid, Insecticides, Malathion, Mosquito larvae, Okra, Residues

published in Agric Res J 54 (3) : 373-379, September 2017

  • Development of Multiple and Cross-Resistance in Cotton Whitefly (Bemisia Tabaci Gennadius) Population in Gezira, Sudan

The effects of endosulfan, deltamethrin and chlorpyrifos on the control of whitefly and development of cross and multiple resistances was investigated in laboratory bioassay with five sprays in the field with three insecticides, the laboratory bioassay test was done to the survival from field spray, each insecticides whitefly population exposed to other two insecticide, the results reveal that the endosulfan population developed high level of cross and multiple resistance after 3rd and 4th to deltamethrin and chlorpyrifos, respectively. The results reveal that when endosulfan used to control whitefly the chemical can be alternate with deltamethrin up to second spray, because after the 3rd spray the RR increase to 10 fold that means the deltamethrin cannot be use after two sprays with endosulfan to control whitefly due the development of cross resistance. In case of chlorpyrifos same scenario will happen but after the 4th spray the RR increase to 10 fold means chlorpyrifos cannot be use after three sprays with endosulfan to control whitefly due to the development of multiple resistances.
 
Keywords – Whitefly Bemisia Tabaci, Cross Resistance, Multiple Resistance, Endosulfan, Deltamethrin, Chlorpyrifos, Resistance Ratio.
 
I. INTRODUCTION
 
Cotton whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), a key pest of many crops throughout subtropical and tropical regions of the world, causes also significant problems in protected agricultural systems in temperate regions (Naranjo, 2001). The impact of direct feeding and honeydew excreta that favors sooty mold production is factors that affect crop yield in both quantitative and qualitative terms (Oliveira et al., 2001). However, the most economically significant losses are due to virus transmission, especially in tomatoes (RobledoCamacho et al., 2009). Chemical management is costly and, at best, provides only partial control because of the rapid development of resistance, a worldwide problem (Cahill et al., 1996 a, b; Vinuela, 1998; Kumar et al., 2008). The cotton whitefly is one of the most important pests of cotton, okra, and other horticultural; ornamental crops. It causes damage by direct feeding and production of large quantities of honeydew, although it is now perhaps the most feared as a vector of up to 60 Gemini-viruses (Bedford et al.. 1992). Insecticide resistance has long been seen by many as the greatest threat to chemical means of controlling noxious organisms including insect-pests of agricultural crops. Some believe that chemical methods will be severely curtailed as a result of resistance. But under field situations most failures are caused by faulty equipment, insecticide of

published in International Journal of Research in Agricultural Sciences Volume 5, Issue 2, ISSN (Online): 2348 – 3997

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