Northern corn leaf blight (NCLB) is a serious foliar disease in sweet corn (Zea mays L. var. saccharata) that considerably affects its productivity. This study evaluated the general combining ability (GCA) and specific combining ability (SCA) for NCLB resistance and yield-related traits in sweet corn. The crossing of five inbred lines and two testers using a line-by-tester design produced 10 F₁ hybrids. These F₁ hybrids and two commercial checks underwent evaluation through a randomized complete block design (RCBD) in 2025 at the PT BISI International, Pujon, Indonesia. The results showed Line B had a desirable negative GCA for disease severity and a positive GCA for yield, identifying it as a robust candidate parent for high-yielding and NLCB-resistant hybrids. Disease severity management was mainly with the non-additive gene action and revealed a weaker association between SCA and the hybrid performance, indicating that no single parameter was sufficient to predict hybrid success. Instead, an integrated selection approach is necessary considering the GCA, SCA, and field performance. The hybrid B × G emerges as the best candidate, showing significant resistance to NCLB and higher yield. The selection of parental genotypes based on combining ability and field evaluation could accelerate the development of disease-resistant and high-yielding hybrids.

Keywords: Sweet corn (Z. mays L. var. saccharata), Exserohilum turcicum, additive, dominance, variance components, hybrid performance

Key findings: The results revealed non-additive gene action predominantly influenced NCLB resistance in sweet corn (Z. mays L. var. saccharata). The identification of hybrid B × G succeeded as the best potential to use in developing sweet corn hybrids with NCLB resistance and higher yield.