Effect of Nitrogen and Chlormequat Chloride on Grain Yield, Phytomass and Water Use Efficiency of Four Rainfed Wheat Cultivars

پژوهشهای زراعی ایران

Article 8, Volume 8, Issue 4 - Serial Number 18, September and October 2010, Pages 636-645   

Document Type: Research Article

DOI: 10.22067/gsc.v8i4.7956

Authors

H. Miranzadeh^* ; Y Emam

Shiraz University

Abstract

Abstract
It appears that the risk of crop production under dry land conditions would be increased due to climate change in the next future decades. Recently, because of in most dryland regions, water use efficiency (WUE) is low due to undesirable production management. Water stress affects many physiological processes, involved in wheat (Triticum aestivum L.) yield formation. In order to improve economy of water use, regulation of root and shoot growth is important. In this study effects of different levels of nitrogen fertilizer and plant growth retardant (Chlormequat Chloride) on grain, phytomass yield and WUE of four rainfed wheat cultivars were examined in a field experiment during 2006-07 and 2007-08 growing seasons in College of Agriculture, Shiraz University located in Badjgah. The results showed that differences between cultivars for grain yield, phytomass and WUE were significant. Effects of chlormequat chloride and nitrogen on grain and phytomass yield were significant. In the first year the highest grain yield and phytomass production (192.4 and 431.2 g/m2, respectively) were obtained from Nicknejad cultivar, Chlormequat Chloride application and using 80 kg/ha nitrogen, and in the second years from Azar-2 cultivar (121.5 and 333.5 g/m2, respectively). Chlormequat chloride and nitrogen had significant effects on WUE in both years. Interaction of chlormequat chloride and 80 kg/ha nitrogen application in both years on WUE were significant (0.95 and 2.35 g/m2/mm, respectively). It appeared that nitrogen and chlormequat chloride application with increase root expansion and proliferation improved soil water uptake. It might be recommended that selecting resistant cultivars to later season drought stress, together with application of chlormequat chloride and nitrogen fertilizer have beneficial effects on increase of WUE of rainfall and could improve wheat grain yield under rainfed conditions.

Keywords: Dryland Wheat Cultivars, Plant Growth Retardant, WUE, Drought Stress, Grain Yield