Weediness and grain yield of specialty maize hybrids cultivated with the application of ecological fertilisers

Maize hybrids (Zea mays L.) with specific traits, such as those with red pericarp, high-protein flints or white kernel hybrids, have increased utility value as they contain some vitamins and minerals beneficial to human and animal nutrition. Furthermore, their cultivation with the application of specific fertilisers could further increase the grain quality through increased participation of macro- and micro-elements that are lacking in the diet. Agronomic biofortification encompasses the application of different production technology that enables better absorption and effective accumulation of essential elements such as iron, zinc, manganese, copper in the edible parts of cultivated plants. On the other hand, fertilisation influences the weed infestation levels and especially the presence of nitrophilic weed species in maize crop. The fertiliser application changes the balance in competition between crops and weeds, not only for nutrients but also for other resources. The effects of different fertilisers were compared within developmental research in the field of ecological agriculture to point up the advantages of microbiological and organic fertilisers, since these fertilisers can contribute to higher yields, but unlike mineral fertilisers, they positively affect the soil and agro-ecosystem. The studies were carried out to determine to what extent agronomic biofortification contributed to the increase of yielding potential and grain quality of maize genotypes with specific traits, as well as how it affected the occurrence and distribution of weeds. The red kernel maize hybrid ZP5048C, high-protein flint maize hybrid ZP737 and white kernel maize hybrid ZP552b, were grown in variants with mineral fertiliser urea, microbiological fertiliser Team Micorriza Plus and organic fertiliser Fertor, that contained essential elements necessary for the nutrition of cultivated plants. No fertiliser was applied to the control treatment. The fertilisation mainly contributed to the increase of weed mass in comparison with the non-fertilised control variant in extremely dry 2017. The highest weed mass was recorded in the hybrid ZP737 in the variant with organic fertiliser, while the lowest weed mass was recorded in all hybrids when microbiological fertiliser had been applied. The highest, i.e. lowest grain yield was recorded in the hybrid ZP5048C (5.83 t ha-1), i.e. ZP737 (3.36 t ha-1), respectively. The protein content was increased at the highest extent in the kernel of ZP737 hybrid after the application of urea, while oil and starch contents were the highest in the grain of white kernel hybrid ZP552b treated with microbiological fertiliser. Due to the specificities and importance of meteorological conditions, the studies will be continued during the next few seasons. .