In our research, we compared the development of three sweet maize hybrids of different genotypes and ripening periods in the most important phenophases. Measurements were made on six occasions: 2-leaf stage, 4–6-leaf stage, 6–8-leaf stage, during male flowering, female flowering, and at maturity. Greenness was measured using NDVI and chlorophyll content was measured with the SPAD meter.

Based on our research results, we found that the examined sweet maize hybrids differed significantly (P<0.05) in terms of phenological parameters such as plant height (149–198 cm), ear length (69–79 cm) and stem diameter (20–24 mm).

The yields of sweet maize hybrids, the weight of the harvested ears, wet grains, and cob differed significantly more than plant height, ear length, and stem diameter.

A satisfactory SPAD value was associated with a high yield. The highest yield was achieved by the NO sweet maize hybrid with excellent productivity. Its raw yield (ear+husk) important for industrial use was 21.953 t ha-1. The lowest yield (by 7.835 t ha-1) was achieved by the PR hybrid.

Analyzing the other generative parameters, we found that the differences are similar in proportions and significantly different in absolute terms. The PR sweet maize hybrid had a wet ear weight of 6.66 tons per hectare, a wet grain weight of 5.460 tons, and a cob weight of 1.200 tons less than the NO sweet maize hybrid.

Keywords: sweet maize, genotype, phenometry, SPAD, NDVI