Response of Maize (Zea mays L.) Grain Yield and Yield Components to Irrigation and Nitrogen Fertilization

Abstract

Grain yield of maize is mostly affected by amount of available water and nitrogen and correlated to yield components. In this 2-years study the influence of different irrigation water amounts (a1=rainfed; a2=60-100% field water capacity (FWC); a3=80-100% FWC), nitrogen fertilizer levels (b1=0 kg*N*ha-1; b2=100 kg*N*ha-1; b3=200 kg*N*ha-1) and hybrids (c1=OSSK515; c2=OS5997; c3=OS5775; c4=OS5885) on grain yield and yield components was tested. Furthermore the correlation analysis as well as direct and indirect path coefficients were used to analyse the connection between yield and yield components (grain number/cob, grain weight, 1000 grain weight, cob length, cob weight) across tested treatments. The influence of all tested factors was significant (P<0.05) in both years of study. Specific study results were obtained in extremely wet year 2010 when irrigation water reduced grain yield and yield components (a1=9.9; a2=8.8; a3=7.8 t*ha-1). Opposite to year 2013 when irrigation water increased grain yield as well as yield components (a1=8.9; a2=9.7; a3=10.3 t*ha-1). Nitrogen fertilizer was significant to all tested variables in both years of the study (b1=5.7; b2=9.2; b3=11.7 t*ha-1 in 2010 and b1=6.3; b2=8.9; b3=10.6 t*ha-1 in 2013). Generally, the greatest amount of nitrogen fertilizer the larger yield or yield components are achieved. The influence of hybrid was significant for all tested variables with exemption to 1000 grain weight and grain weight/cob during growing season 2013. In both years of the study hybrid c2 OS5997 achieved the highest yield as well as yield components. Correlation analysis showed strong positive correlation between yield and cob weight (r=0.77 (2010); r=0.84 (2013)) what is confirmed with direct and indirect path analysis test.