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Effects of nitrogen rates on grain yield and nitrogen agronomic efficiency of durum wheat genotypes under different environments
Author(s) -
Ayadi S.,
Karmous C.,
Chamekh Z.,
Hammami Z.,
Baraket M.,
Esposito S.,
Rezgui S.,
Trifa Y.
Publication year - 2016
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/aab.12262
Subject(s) - biology , agronomy , nitrogen , crop , yield (engineering) , biomass (ecology) , grain yield , chemistry , materials science , organic chemistry , metallurgy
Durum wheat is an important staple food crop in Tunisia and other Mediterranean countries and is grown in various climatic conditions. Production and yield are however severely limited not only by drought events but also by reduced levels of nitrogen fertilisation. A study was carried out at two locations in the sub‐humid area of Tunisia: Mateur in 2009–10 and 2010–11 and Beja in 2011–12 and 2012–13 under rainfed conditions. Four durum wheat genotypes (landraces: Bidi, Azizi; improved: Om Rabia, Khiar) were evaluated for nitrogen agronomic efficiency and related agronomic traits under various nitrogen rates: 0, 50, 100, 150, 200 and 250 kg N ha −1 , with three replications. There was a significant interaction effect ( P ≤ 0.001) environments × genotypes × N treatments for grain yield ( GY ), biomass yield ( BY ), harvest index ( HI ), partial factor productivity of applied nitrogen ( PFP N ) and nitrogen agronomic use efficiencies ( NAE ). GY was the most affected trait by nitrogen applied showing an increase of 94% under high N treatment (250 kg N ha −1 ) compared to control plots without N treatments. A significant linear regression exists between GY (0 N) and GY for the different N rates ( r = 0.70; P < 0.001). This effect was more pronounced for improved genotypes than landraces for all parameters excepting BY and NAE BY . BY showed +11% increase in landraces than improved genotypes. PFP N showed an average decrease of 65% under high‐N fertilisation with 10% prevalence for improved genotypes. Landraces tend to promote vegetative growth while grain filling efficiency was higher for improved genotypes.