Effect of intercropping on the incidence and severity of damage of fall armyworm (Spodoptera frugiperda J.E. Smith) on maize (Zea mays l)

The fall armyworm (Spodoptera frugiperda J.E. Smith) is an invasive anddestructive pest that came into Nigeria recently, where it has established itself as one of themaize’smost important insect pests. The effect of intercropping on the incidence and severity of damage tomaize was investigated, where maize was intercropped with five different crops, namely, cowpea, groundnut, soya bean, sorghum and roselle, and controlled plots with sole maize. Randomized Complete Block Design was used, and the treatments were replicated four times. Parameters taken were number of damaged leaves per plant, severity of damaged on leaves, number of damaged ears per plot, severity of damage on ears and yield per plot. The result of the study had shown that plots where maize was intercropped with soya bean had, significantly (P<0.05), the lowest incidence (17.5 %) and severity of damage (2.8) compared to plots with sole maize, that had the highest incidence (43.8 %) and severity of damage (5.5). The percentage of damaged tassels was the highest in plots where maize was a sole crop (17.5 %), followed by maize and sorghum (15 % each). The lowest percentage of damaged tassels was recorded on maize that was intercropped with soya bean (5.0%), and was significantly (P< 0.05) lower than the rest of the five treatments. Similarly,the percentage of damaged ears was the highest with maize as a sole crop (15 %) and lowest on maize intercropped with soya bean (3.7 %). Highest yield was also recorded in plots where maize was intercropped with soya bean (7.43 tons/ha), followed by maize-cowpea intercropped plots (6.44 tons/ha) and maize-groundnut intercropped plots (5.23tons/ha) and plots where maize was a sole crop had, significantly the lowest yield (P< .05) The result of this study is indicative of the potentials of using intercropping, especially when legumes such as soya bean, are included, as a management tactic against fall armyworm on maize.This will reduce a total reliance on synthetic insecticide to manage the insect pest by small holder maize farmers in Nigeria.