Physical characteristics of several corn varieties and the interaction between planting patterns and varieties on pest attacks Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) and ant population Oecophylla smaragdina (Fabricius)

Abdul FattahI Nyoman WidiartaMuhammad Yasin^*Sahardi MuliaMuh Basir NappuSurianto Sipi^*Muhammad Fitrah HannanErwin NajamuddinIdaryani IdaryaniHerniwato HerniwatiSyafruddin SyafruddinPaesal PaesalSusilawati SusilawatiYudhistira NugrahaM Sudjak SaenongDidik HarnowoMuh AsaadWardah WardahNurjanani NurjananiWanti DewayaniAmiruddin Syam

• National Research and Innovation Agency (BRIN), Bogor, Indonesia

Superior varieties and planting arrangements significantly impact maize productivity. This research aimed to examine the effects of planting models (farmers' tile model vs. legowo 2:1) and maize varieties on agronomic performance, productivity, and the incidence of damage caused by Spodoptera frugiperda pests and the abundance of predatory weaver ants (Oecophylla smaragdina). The study was conducted using a two-factor split-plot randomized block design: main plots comprised the planting models (tile pattern: 70 cm × 40 cm and legowo 2:1: (50 cm × 35 cm) × 90 cm), and sub-plots involved seven maize varieties (Srikandi Kuning, Pulut Uri, Provit A1, Anoman, Srikandi Ungu, Bisma, and Sukmaraga), arranged in 150 m² plots with three replicates. Results demonstrated significant varietal differences in agronomic traits, including plant height (168.78-219.30 cm), leaf area (6.60-7.85 cm), flowering time (45.33-49.00 days after planting), and ear height (89.42-119.32 cm).Legowo 2:1 planting resulted in higher maize grain yield (7.89 t ha -¹) than the farmers' model (5.38 t ha -¹). Moreover, the legowo 2:1 arrangement significantly reduced leaf damage intensity by S. frugiperda (19.12%) compared to the tile planting pattern (21.26%), as well as corn cob damage (11.58% vs. 13.09%). Varietal differences significantly influenced S. frugiperda population density, ranging from 0.43 to 1.23 larvae per plant, with the lowest incidence in Bisma and the highest in Sukmaraga. The intensity of leaf and cob damage was lowest in Bisma (12.32% leaf, 8.80% cob) and highest in Sukmaraga (25.23% leaf, 15.03% cob).Weaver ant populations negatively correlated with S. frugiperda numbers and associated plant damage. Biplot analysis indicated Bisma as optimal under the legowo 2:1 model and Anoman optimal under the farmers' tile model, while Provit A1 showed suboptimal performance under the legowo arrangement. Therefore, varietal choice and appropriate planting models can effectively enhance maize productivity and reduce pest pressure. These findings provide valuable insights and recommendations for agricultural stakeholders to optimize maize yields through strategic planting configurations and variety selection.