Evaluation of the Effect of Using 2,3-dichlorovinyl Dimethyl Phosphate (sniper) as Storage Insecticide on Quality of Cowpea (Vigna unguiculata (L.) Walp) Nutritional Content
The effect of 2, 3-dichlorovinyl dimethyl phosphate (sniper) application on the nutritional contents of cowpea over a period of time has been investigated. The chemical free cowpea samples were purchased directly from local farmers in Mubi town, Adamawa State. Three different treatment rates of 5, 10 and 15 ml of sniper were used. Each of the treatment rates was applied to 13 kg of cowpea and was placed in an air tight galloon. Another galloon containing 13 kg of cowpea without chemical treatment was used as the control sample. These were kept for a period of 30 and 60 days before analysis. The proximate and mineral components of the cowpea were analyzed using standard procedures. Assessment of the proximate composition revealed varied concentrations of protein, carbohydrate, ash, fat, crude fibre and moisture that ranges between 22.79-26.16%, 58.85-60.86%, 3.85-5.88%, 2.25-2.53%, 1.52-1.76% and 5.90-6.85%, respectively. Most of the proximate compositions were observed to decrease with increase in sniper concentration and storage duration. The proximate contents at 60 days after treatment application were observed to be significantly lower than that at 30 days. The mineral components analyzed ranges between 185.03-195.54 mg/100 g (P), 226.32-245.76 mg/100 g (Ca), 80.76-85.92 mg/100 g (Mg) and 595.25-642.34 mg/100 g (K) respectively; and at day 60 it ranges between 186.54-198.65 mg/100g, 251.07-262.73 mg/100 g, 86.48-90.12 mg/100 g and 650.06-700.04 mg/100 g respectively. The mineral contents were observed to increase with increase in treatment concentrations as well as storage duration. Therefore, sniper has significant effect on the proximate and mineral contents of cowpea. The effect depends on the rate and duration of storage. The use of sniper as an insecticide in the storage of cowpea should therefore be discouraged.