Važnije morfološke osobine i sadržaj biogenih elemenata kod hibrida kukuruza pri raznim nivoima đubrenja / More important morphological traits and the content of mineral elements in maize at the different levels of fertilization

The modern maize production is based upon knowledge of plants requirement, the dynamics of the uptake of nutrients during the vegetation and their role in the formation of particular plant organs which are key issue in determining the the time and method of the fertilizer application. Genotypic differences in uptake and accumulation of mineral elements between the different maize genotypes are noticeable in their different response to fertilization. Not considering the genotypic characteristics of individual hybrids in maize growing could result with incomplete utilization of their genetic potential and with impartial use of fertilizers. In this PhD thesis we studied the effect of different fertilization systems (control – P60K60 const; P60K60const. + N min spring; P60K60 const. + N40 autumn + N min spring; P60K60 const. + N60 spring; P60K60 const. + N100 spring; P60K60 const. + N40 autumn + N60 spring + Zn; P60K60 const. + N40 autumn + N80 spring + Zn and P60K60 const. +N160 spring +Zn) on the main morphological traits (ear hight, plant tassel height, ear length, ear diameter, number of kernels per row, number of kernel rows per maize ear), the content of mineral nutrients in leaf (nitrogen, phosphorus, potassium, calcium, magnesium, manganese, zinc, sodium and copper), the content of mineral elements in the grain (nitrogen, phosphorus, potassium, calcium, magnesium, manganese, zinc, iron, sodium and copper), quality parameters (protein, soluble protein, oil, starch, total sugar, phytin, inorganic phosphorus, SH thiol group, total phenols and tryptophan), yield and yield components of the NS maize hybrids from different cycles of selection. Obtained results of this research showed that selected hybrids (genotypes) of maize used in the study differs in the expression of investigated traits; expression of characteristics was significantly influenced with the genetic potential of the tested hybrids, fertilizaion systems and the amount of nutrients; studied genotyped varied in the efficiency of nutrient uptake from soil reserves and applied fertilizers and/or their efficient utilization with crops and as such are desirable in terms of economic efficiency of the maize production and the agroecosystem protection. Enhanced ability of accumulation, exploitation and/or reutilization of mineral nutrients can provide the basis for the development of maize breeding programs based on productivity and grain quality. Considering the maize production in the Republic of Serbia, identification and development of genotypes with favorable grain quality traits could help in development of maize utilization values which would allow greater export of these products in the international markets. This research has not only theoretical but also practical value, and the results have contributed to a comprehensive perception of the maize production improvement in the country and beyond.