Assessing the Efficacy of Imidacloprid 20% SL as an Insecticide against Aphids in Cultivated Okra Plants in a Tropical Ecosystem: A Case Study of Mamponteng – Kumasi, Ghana for the 2011 and 2012 Cropping Period

2013

English

Okra, Abelmoschus esculents is an important vegetable widely grown in Ghana. The nutritional value derived from the consumption of okra cannot be over emphasized. However, okra has been regarded as a minor crop in Ghana, and for that matter, little or no attention is paid on the cultural practices that need to be adhered to in the cultivation of this important vegetable. The production of Okra in Ghana is severely affected by pests' infestation, notably among them is aphids (Aphis gossypii Glover). It is therefore considered imperative and worthwhile to find a more robust and effective method of controlling aphids' infestation in okra plantations in Ghana rather than resorting to the traditional methods which are to larger extent less effective in controlling aphids' population in tropical ecosystem. A field experiment was therefore conducted to find the biological efficacy of imidacloprid 20% SL on aphids in okra. The research was conducted in the 2011 and 2012 planting periods. Three doses of imidacloprid (25g, 50g and 75g active ingredient per ha) were used to test the efficacy of the treatment as compared to untreated plots (control). In both seasons, plants in the untreated plots recorded the highest mean number of aphids whereas those in the imidacloprid-treated plots had the lowest mean count. This study however shows that imidacloprid-treated plots had relatively more yield than the control (untreated plots). The research shows that efficacy of the insecticide is found to have a positive correlation with the rate of application. We therefore recommend 75g active ingredient of imidacloprid 20% SL /ha to effectively deal with aphids infestation in okra plants.

Amoakwah, E.; Frimpong-Manso, J.; Essumang, D. K.