Influence of sowing dates on the population density of the fall armyworm Spodoptera frugiperda (JE. Smith) and its damage on maize plants in Chad

Abstract

Fall armyworm, Spodoptera frugiperda, constitutes a major challenge for maize growers and scientists, as it threatens the food security  of all these countries. In order to contribute to the sustainable management of the pest in Chad, this study aimed at assessing the effect  of sowing dates on the level of maize infestation in the field. Three sowing periods for maize, chosen in connection with the onset of  rains, were tested (the early sowing (July 2nd), the intermediate sowing (July 16th), and the late sowing (July 30th)) with a Fall armyworm- sensitive maize variety. The results indicated a significant effect of sowing dates on the population densities of the pest, with the early  sowing hosting the highest density and infestation rate of the pest, compared to the intermediate and late sowing (P < 0.0001). Moreover,  the results showed a significant impact of sowing dates on grain yield (P < 0.005), with significantly higher values in the  intermediate sowing while, the early and late sowing recorded lower yields. These results indicated that the intermediate sowing should  be recommended for this early maturing and fall armyworm-sensitive maize variety to limit population outbreaks of this pest, together  with its adverse consequences on maize yield.