Comparison of Fall Armyworm (Spodoptera frugiperda) Damage Among Forage Corn Varieties

Abstract

Fall armyworm (FAW; Spodoptera frugiperda) initially invaded Japan in July 2019 and is one of the most important pests to forage corn. Fall armyworm damage is concerned to expansion and reduce of its damage is urgent issue. Resistant forage corn variety reduce FAW damage easily and inexpensively. But there is no knowledge of forage corn resistance to FAW damage. Therefore 50 forage corn varieties were tested for resistance to FAW damage across each four summer seeding times in 2021 and 2022. Leaf damage assessments after flowering revealed significant differences among varieties, with correlations in damage scores observed across seeding times. However, multiple comparisons showed no variety combinations with statistically significant differences, suggesting no highly effective FAW resistance of varieties tested in this study. When categorized into four maturity groups, late- or later-maturing varieties sustained less damage compared with earlier-, early-, and medium-maturity groups. Ear damage patterns mirrored leaf damage. From the above results, some late- or later-maturing varieties will show relatively low damage levels.