Effect of different rates of urea fertilization on yield and some biochemical and physiological properties of four wheat cultivars under two irrigation regimes

Saeed Samsami,Mahdi Zare,Bahram Amiri,Foroud Bazrafshan,Abdollah Bahrani

doi:10.5586/aa.1788

Abstract

Drought stress is one of the most serious limitations for the growth and yield of wheat worldwide. Under changing climatic conditions, understanding the urea fertilizer requirement for wheat could be helpful for improving the quality and quantity of yield. The effects of different urea fertilizer levels were evaluated for some biochemical and physiological properties of four wheat cultivars under two irrigation regimes. This experiment was conducted in a split-split plot, randomized complete block design, with three replications. The main plots were irrigation (normal irrigation and irrigation terminated at the stem elongation stage). The experimental plots employed four wheat cultivars (‘Shirudi’, ‘Chamran’, ‘Chamran 2’, and ‘Sirvan’) and four levels of urea fertilizer treatment (0, 120, 240, and 360 kg ha−1), at two locations, Khodayan (52°20' E, 29°8' N) and Nasrabad (52°64' E and 29°58' N), Fars Province, Iran. Results from the full analysis of variance across the two locations indicated considerable differences in yield parameters between irrigation, rates of urea application, and cultivars (p &lt; 0.01). Interaction effects of location, irrigation, cultivars, and urea levels were also significant for Chl b, 1,000-seed weight, and seed yield (p &lt; 0.01). The data indicated that termination of irrigation led to a reduction in RWC (20%), total chlorophyll content (30%), carotenoids (19%), 1,000-seed weight (18%), grain yield (29%), and a promotion in ionic leakage (17%) and proline accumulation (4%), in comparison to the controls. According to these results, ‘Chamran’ and ‘Shirudi’ showed the greatest tolerance to reduced irrigation and that using 240 kg ha−1 urea may effectively moderate the adverse effects of this in these and other wheat cultivars.

Highlights

Water deficit is a major stress for crop production which can have substantial adverse impacts on physiological and biochemical processes, plant growth and development, and crop yield components [1]
Comparison between treatments means showed that termination of irrigation led to a 20% reduction in relative water content (RWC) in comparison to the control
RWC increased by 5%, 8%, and 12% after application of 120, 240, and 360 kg ha−1 urea, respectively

Summary

Introduction

Water deficit is a major stress for crop production which can have substantial adverse impacts on physiological and biochemical processes, plant growth and development, and crop yield components [1]. It is important to seek new drought resistance genes from different wheat genotypes and introduce new cultivars for conventional breeding [2]. The nitrogen requirement of the crop may be affected by drought stress. Understanding the effect of crop water status for nitrogen application is likely beneficial for ensuring the highest yield [3]. Its success depends more on the soil water status than the timing and amount of its application [4]. Stages of vegetative growth including tiller proliferation depend on the accessibility of water and nitrogen supply

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