engleski

Influences of liming on grain yields and nutritional status of parents of maize hybrids

Maize is most spread arable crop in Croatia. In the last decade period (1980-1989), harvested area of maize was 506,575 ha/year or 33% of total arable lands of country. In general, the most fertile soils are use for seed-maize growing, but partially it is organized under stress soil conditions, especially on acid soils. For this reason we tested response parents of maize hybrids to liming. Ten parents (Os77-9, W64A, Os1-48, Os86-39, Os87-24, Os89-9, Os36-16, Mo17, B73 and Os30-8) of maize single-cross hybrids were grown during the growing season of 1993 under field conditions. Soil was classified as planosol (pH in KCl = 4.2; humus contents 1.8%). Two fertilization treatments were applied: a) standard fertilization and b) standard fertilization + liming with sugar factory wasted silt (carbocalk - product of Osijek Sugar Factory: 15 t/ha; incorporation to 15cm of soil depth immediately before maize sowing). The field trial was conducted by split-plot method in four replications. The experimental plot measured 8.05m2. Theoretical plant density was 57140 plants/ha. Grain yields were calculated on theoretical plant density of mother component of seed-maize (42860 plants/ha) and 14% moisture basis. The ear-leaf was taken for chemical analysis (Ca, Mg, Zn, Mn and Fe) at beginning of the silking stage (25 leaves in mean samples) from each plot. As affected by liming, grain yields were increased for 23% (mean 2124 and 2623 kg/ha, for standard fertilization and liming, respectively). At the same time, contribution of female-sterile plant (FSP) was decreased (mean 15% and 6%, respectively), while plant density realization (mean 78% and 87% PDR ) and plant height (mean 150 and 168cm PH) were increased. Also, ear-leaf composition was in close connection with fertilization as follows (means of standard fertilization and liming treatment): 0.81 and 1.13% Ca, 0.25 and 0.38% Mg, 43 and 29 mg Zn/kg, 106 and 51 mg Mn/kg , 177 and 150 mg Fe/kg, respectively (calculations on dry matter basis). Also, considerable differences of tested properties were found among the parents of maize hybrids as follows (minimum and maximal values): 1072 and 3420 kg/ha (grain yield), 1 and 34% (SPC), 67 and 94% (PDR), 150 and 196 cm (PH); ear-leaf composition = 0.67 and 1.55% Ca, 0.22 and 0.54% Mg, 52 and 115 mg Zn/kg, 125 and 209 mg Mn/kg , 125 and 209 mg Fe/kg. Specifies of individual parents were as follows: Os77-9 = the highest Mn and Fe concentrations; Os1-48 = the highest Zn concentrations, the lowest SPC and the lowest PH; Os86-39 = the highest grain yield; Os87-24 = the highest PDR; Os89-9 = the lowest PDR, the highest Ca and Mg concentrations; Os36-16 = the lowest Mg , Zn and Mn concentrations; Mo17 = the highest PH; B73 = the lowest grain yield and the highest SPC; Os30-8 = the lowest Fe concentrations. In four parents (Os77-9, W64A, Os1-48 and B73), liming resulted by insignificant differences of yields, while in remaining six parents tested, they increased as follows: 20% (Os86-39), 28% (Os36-16), 37% (Os89-9), 40% (Os87-24), 44% (Mo17) and 100% (Os30-8). In general, the similar specific trend of ear-leaf composition was found among tested maize genotypes following standard fertilization and liming.

Liming; Corn; Yield; Hybrids

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