Evaluation of Complete Fertilizer in the Aspect of the Antioxidant Enzyme System of Maize Hybrids

Abstract

Studies on physiological and biochemical processes in crops are highly relevant for breeders to produce hybrids with high yield. Two different maturity groups of maize hybrids were tested in this study. The research site was located at the Látókép Experimental Station of the University of Debrecen and the experiment lasted for 2 years. The examined nitrogen ranges were separated into two parts. Firstly, the effects of nitrogen fertilizer ranging from 120–300 kg ha−1 were examined, supplemented with a constant, high-level P2O5 and K2O. Secondly, the optimal ratio of N:P:K was measured. In order to monitor the health status of maize hybrids, stress indicators including the activity of ascorbate peroxidase (APX), and superoxide dismutase (SOD), the rate of lipid peroxidation (LP), and grain yield were measured. The samples were taken in five phenological stages. Variance analysis based on nitrogen fertilizer showed variation in sampling times and fertilizers on APX, LP, and SOD. Variance analysis based on NPK indicated variation in sampling times, years, and fertilizer levels on APX, LP, and SOD. Correlation analysis showed that yield correlated negatively with SOD during the use of NPK fertilizer, as the use of nitrogen fertilizer cannot make corrections to yield with SOD but phosphorus and potassium can correlate with yield, and SOD. Principal component analysis showed that NPK5 and N5 had maximum stability and effect on yield. The activity of APX had the highest value during silking, and LP was in the V14 leaf stage. The correlation and principal component analysis showed that silking and the V14 leaf stage are the most important stages for yield, thus, higher attention must be paid to these stages in the LP and the activation of APX to achieve maximum yield.

Keywords

• antioxidant response
• field experiment
• long-term experiment
• maize
• nitrogen fertilizer