Genotypic effects on boron concentrations and response on boron fertilization in maize inbred lines

Boron (B) deficiency in maize can result in barren cobs attributed to silks being nonreceptive which is particularly important for the female parent in seed production. The objectives of this study were 1) to investigate genotypic differences among nine female inbred lines used in seed production for B concentration in ear-leaf and grain, as well as for grain yield and moisture in a three-year experiment (2006-2008) and 2) to determine response and relations among the traits when four of the female inbred lines are treated by foliar boron fertilization - three times in 10-days interval with 0.5% Solubor solution (17.5% B) during one growing season (2008). The investigations were performed on Experimental field of Agricultural Institute Osijek, (soil type: eutrical cambisol). Highly significant differences among the nine female inbred lines were detected for B concentration in ear-leaf (from 14.7 to 46.7 mg B kg-1) and grain (from 1.20 to 2.06 mg B kg-1) as well as for grain yield (from 3.33 to 4.83 t ha-1) and grain moisture (from 14.7% to 26.6%). However, there were also significant effects of growing season and the genotype by environment interaction for all four traits. Positive and moderate correlations were found between the boron status in plant and grain yield. Although B concentrations were considerably increased by foliar boron fertilization (averages 41.7 and 125.3 mg B kg-1 in leaves, 1.79 and 2.80 mg B kg-1 in grain, for control and fertilization, respectively), in general grain yield differences among treatments were non-significant. (averages 5.21 and 5.15 t ha-1, respectively).