Effect of Nitrogen Fertilization and Variety Differences on Nitrate Reductase Activity of Wheat (Triticum aestivum)
I. MANOLOV, V. CHALOVA and S. KOSTADINOVA
Agricultural University, BG-4000 Plovdiv, Bulgaria
MANOLOV, I., V. CHALOVA and S. KOSTADINOVA, 1999. Effect of nitrogen fertilization and variety differences on nitrate reductase activity of wheat (Triticum aestivum). Bulg. J. Agric. Sci., 5: 599-604
The study included 9 varieties and lines winter soft wheat grown on three levels of nitrogen fertilizing (N0, N120, N240). The effect of nitrogen fertilization, variety differences and their interaction on plant nitrate content (NC) and nitrate reductase activity (NRA) in tillering, jointing, flowering stages and yield were studied. Analyse of variance showed that nitrogen fertilization had the highest effect on NC and NRA. The three fertilizing levels formed different models of NC and NRA changes during plant growth.
Concerning to obtained yields, variety differences showed much lower effect in comparison with soil nitrogen level. The varieties Sadovo 1, Record, and LC-318 were the most productive at nitrogen level N240. The combination of lower nitrogen levels and unfavourable climate conditions did not lead to maximum use of genetic potential of varieties.
Key words: wheat, nitrate content, nitrate reductase activity
Abbreviations: nitrate content (NC), nitrate reductase activity (NRA), nitrate reductase (NR)