THE INFLUENCES OF GENOTYPE AND SOIL ON MAIZE NUTRITIONAL STATUS AND FREE PROLINE CONTENT

Five maize hybrids were grown on two soils in eastern Croatia (Rakitovica gleysol and Bicko selo luvisol) in the growing season of year 2007. Significant differences in leaf K, Ca, Mg, Fe, Mn and Zn content (the ear-leaf at flowering stage) were established depending on specific agroecological conditions of the localities. For example, leaf K, Fe, Zn and proline contents were higher on the gleysol, probably due to lower soil pH, and more severe drought stress. Leaf K content was negatively related to Ca and Mg. Synergistic relation of K to proline in maize leaves could be the reaction of plant to environmental stress, whereas proline was negatively related to grain % in ear mass. Soil influence was not significant for evaluated yield components (grain ear-1, ears plant-1and grain dry mass plant-1). The obtained differences in yield components among hybrids imply the necessity of further evaluation of their ability for nutrient utilization from acid soils and grain production in different climate conditions.