Evaluation of damage by Spodopetera frugiperda (J. E. SMITH, 1797) (Lepidoptera: Noctuidae) to maize cultivars.

Abstract

The objective of this work was to evaluate leaf damage by Spodoptera frugiperda to maize cultivars, in two sowing times, in the region of Jaboticabal, state of São Paulo, Brazil. A visual scale applied during the phenological stages of 4, 8, and 2 developed leaves was used to evaluate the extent of leaf damage. The experimental design was the randomized complete blocks in a split-plot arrangement, in which the plots were represented by 25 cultivars and the subplots by the application or no application of chemical products to control the insect. The insecticide application resulted in reduction of the leaf damages in the off-season and the regular season crops. In the stage of 2 developed leaves in the off-season, and 4 developed leaves in the regular season, the most attacked cultivars were Z 8420, BRS 30, and XB 702 (off-season), and DKB 440 and AG 9090 (regular season), which showed torn leaves in the cartridge. When chemical control was applied, BRS 30 was the less attacked cultivar.Additional keywords: fall armyworm; leaf damage; phenological stages; Zea mays L.