The effect of leaf defoliation on remobilization and remobilization efficiency in bread wheat cultivars under water deficit stress

Document Type : Research Paper


1 Former M.Sc. Student and Professor, College of Agriculture, Shiraz University, Iran

2 Professor, College of Agriculture, Shiraz University, Iran

3 Assistant Professor, National Salinity Research Center, Agricultural Research, Education and Extension Organization (AREEO), Iran

4 Former M.Sc. Student, College of Agriculture, Shiraz University, Iran


In order to evaluate the effects of leaf defoliation on assimilate remobilization in wheat under water deficit stress, a field experiment was carried out as a split split plot based on randomized complete block design with three replications at College of Agriculture, Shiraz University during 2013-2014 growing season. The treatments included water stress: normal irrigation and cutting-off irrigation at anthesis as main plot, wheat cultivars: Pishtaz, Chamran and Marvdasht as sub plot, and levels of source manipulation: non-defoliation, defoliation at mid-stem elongation or mid-anthesis as sub sub plots. The results showed that leaf defoliation, especially at stem elongation reduced grain yield significantly (Pishtaz 19.2%, Chamran 24.7% and Marvdasht 24.9%). The highest remobilization was also obtained from leaf defoliation treatment at stem elongation, so that defoliation at stem elongation increased proportion of stem and ear in grain yield by 1.6 and 1.4 times, respectively; however, it could not compensate yield loss resulted from leaf defoliation. Pishtaz and Marvdasht cultivars had the highest and the lowest remobilization, respectively. Water deficit enhanced remobilization and relative proportion of stem and ear in yield, so that mean of relative proportion of stem and ear in grain yield were 9.1% and 6.8% under normal and 15.2% and 26.3% under water stress conditions, respectively, meanwhile relative proportion was greater for Pishtaz cultivar. In general, water deficit stress and leaf defoliation, especially at early growth season increased remobilization before flowering and proportion of ear and stem storage in grain yield.


Main Subjects

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Volume 48, Issue 2 - Serial Number 2
September 2017
Pages 545-556
  • Receive Date: 12 January 2016
  • Revise Date: 12 November 2016
  • Accept Date: 21 November 2016
  • Publish Date: 23 August 2017