Interactive Effects Of Dichlorvos, Dimethoate, And Cypermethrin On Physiological And Oxidative Responses Of Okra
Okeke, Chinedu Gabriel
Department of Environmental Management and Toxicology, Federal University of Petroleum Resources, Effurun, Delta State, Nigeria
Abstract
The study investigated the effects of individual and combined applications of three commonly used pesticides— dichlorvos, dimethoate, and cypermethrin—on the growth and biochemical responses of okra (Abelmoschus esculentus) plants. The experiment was conducted in a greenhouse at the College of Science, Federal University of Petroleum Resources, Effurun, Nigeria. A completely randomized design was employed, utilizing eight treatment groups: a control group (sprayed with water) and seven groups exposed to single pesticides or combinations. Growth parameters, including plant height, stem girth, and relative water content (RWC), were monitored over a four-week period. Biochemical markers, such as catalase (CAT) and superoxide dismutase (SOD) activities, along with malondialdehyde (MDA) concentrations, were analyzed to assess oxidative stress and ant oxidative responses. The results showed that all pesticide treatments significantly inhibited plant growth compared to the control, with the most pronounced reductions observed in the three-pesticide combination group. RWC declined progressively with increasing pesticide complexity, indicating impaired water retention under pesticide-induced stress. Biochemical analyses revealed elevated CAT and SOD activities and increased MDA concentrations in all pesticide-treated groups, reflecting oxidative stress. Combined pesticide treatments exhibited synergistic effects, causing significantly higher oxidative stress and ant oxidative enzyme activities than single treatments. Root tissues showed the highest oxidative stress, followed by stems and leaves. These findings highlight the detrimental effects of pesticide combinations on okra physiology and biochemistry, emphasizing the need for careful pesticide management to minimize environmental and agricultural risks. This study provides valuable insights into the interactive effects of pesticides, aiding in the development of sustainable pest control strategies