Preliminary Biochemical, Physiological, and Yield Responses of Sweet Corn to Organic and Chemical Fertilization Across Genotypes

Sweet corn (Zea mays var. saccharata) is a widely cultivated crop valued for its sweet flavor and high nutritional content. Over the past decade, the area devoted to sweet corn grain production has increased substantially, driven by both its nutritional qualities and its economic value. In this context, we aimed to evaluate the impact of three genotypes (Royalty F1, Hardy F1 and Deliciosul de Bacau,) under two fertilization types (chemical and organic) compared with a control version on yield, biometrical, biochemical, and quality parameters. This research was carried out between 2022 and 2023 at an experimental station situated in the North-East region of Romania. The results revealed significant influences of cultivar, fertilization method, and the interaction between these two experimental factors on most of the analyzed indicators. Regardless of the fertilization type, the genotype Hardy F1 showed higher levels of photosynthetic activity, polyphenols (2.22 mg/g d.w.) and sucrose (6.7 g/100 g d.w.), leading to greater yield (13,995 kg/ha) than that of Deliciosul de Bacau and Royalty F1. Research on fertilization has shown that sweet corn grains under an organic method have higher levels of lycopene, chlorophyll a, chlorophyll b, total phenolic content (TPC), and fructose. In contrast, chemical fertilization more effectively supported growth, photosynthetic activity, yield, and the content of antioxidants and tannins. Regarding the combined influence of these factors, most of the nutritional characteristics of Royalty F1 were enhanced by organic fertilization, whereas those of the Hardy F1 genotype were improved by chemical fertilization. These findings provide practical guidance for selecting appropriate genotype–fertilization combinations to optimize the yield and nutritional quality of sweet corn and highlight key priorities for further research on sustainable fertilization strategies under climate change conditions.