Nitrogen Fertilizer Rates and Pesticides Interaction Effect on Maize and Fall Armyworm Performance in Northern Ghana

Abstract

Maize is in high demand due to its significant contribution to food security and income generation. However, in Ghana, its production is adversely affected by low soil fertility and fall armyworm (FAW) infestation. The application of fertilizers and sound FAW control could contribute to increased maize yield in the country. This study was conducted to determine the effect of nitrogen fertilizer rates and FAW pesticide application on growth and yield of maize. The experiment involved four levels of fertilizer rates (No N- fertilizer, N- fertilizer at 40 kg∙ha−1, N- fertilizer at 60 kg∙ha−1, N- fertilizer at 80 kg∙ha−1,N- fertilizer at 100 kg∙ha−1), and two levels of pesticides application (Emastar 125 EC, Pesticide-free plot) in split-plots design with four replications. The results show that generally, fall armyworm number of egg mass, larvae, and leaf injury severity were significantly (p < 0.01) lower on the sprayed plots. The number of egg masses on unsprayed plots (51.4%) and sprayed plots (49.8%) were highest on nitrogen fertilizer at 100 kg/ha and least on 40 kg per/ha, compared to the control. The 100 kg/ha fertilizer rate with or without insecticides spray gave the highest number of egg mass, larvae, and mean crop damage while the least occurred on 40 kg/ha treatment. Grain yield, hundred seed weight, and stover dry weight were significantly (p < 0.01) higher on sprayed plots, compared to unsprayed plots. Furthermore, the 80 and 100 kg/ha fertilizer rates with or without insecticides spray gave the highest grain yield, hundred seed weight, and stover dry weight. The present findings suggest that the appropriate nitrogen fertilizer application and strategic use of pesticides could improve maize yield as well as mitigate fall armyworm infestation.