Influence of Sowing Dates on Physiological Traits, Yield Components and Grains Rot Disease Resistance in Maize (Zea mays L.) Cultivars

The study investigated the impact of three sowing dates (May 15, June 15, and July 15) on physiological traits, yield components, and grain rot disease infection rates in maize cultivars, including single-cross hybrids (SC131 and SC168) and the three-way cross TWC324 during the 2023 and 2024 growing seasons. Early planting (May 15) resulted in the highest significant values for dry matter accumulation (g/m²) and leaf area per plant (cm²). Additionally, early sowing significantly enhanced photosynthetic pigment content in leaves, yield and yield components (plant height [cm], ear diameter [cm], ear height [cm], ear weight [g], ear length [cm], 100-grain weight [g], grain weight per ear [g], grain yield [ard/feddan]), as well as grain crude protein and carbohydrate content (%). Furthermore, early planting reduced infection levels by Fusarium verticillioides, F. semitectum, Aspergillus niger, A. flavus, and Penicillium spp. compared to later sowing dates (June 15 or July 15). Among the tested cultivars, SC168 outperformed the others in all measured traits. The highest mean values for physiological parameters, yield characteristics, grain quality components, and resistance to grain rot disease were achieved by planting SC168 at the early sowing date (May 15) in both growing seasons. Therefore, this combination is recommended for optimal maize production under similar conditions.