Sweet Corn Yield and Sugar Content Depending on Genotype, Sowing Date and Irrigation

The research examines the influence of year, sowing date, sweet corn genotype (Zea mays L. saccharata Sturt.), and irrigation norm on productive traits and sugar content in sweet corn kernels. The experiment was set up in a completely randomized block design with four replications. In both years, sowing was done in two periods: end of April - beginning of May and mid-July. Three hybrids (Enterprise, Union, and Sweet Nugget) were observed under three irrigation treatments: full norm (100%), reduced norm (50%) and natural wetting (control). Combined analysis of variance (pooled ANOVA) showed a statistically significant effect on all examined yield and sugar content parameters, as well as their higher-order interactions. Hybrid Enterprise stood out as the most productive, with the highest values of ear weight, kernel weight (up to 272.13 g) and kernel yield (up to 16.25 t ha-1 in the first year and up to 13.66 t ha-1 in the second year), especially in the second sowing date with full or reduced irrigation norm, with a shelling percentage over 70%. The highest content of total sugars (39.71% in the first year and 40.39% in the second year) was achieved in the Sweet Nugget hybrid in the first sowing date under natural moisture conditions, where a slight water deficit stimulates sugar concentration. The obtained results highlight the advantages of the Enterprise hybrid for high yield under irrigation conditions and the Sweet Nugget hybrid for kernel quality (sweetness), and underscore the importance of factor interactions.