Nitrogen and plant population change radiation capture and utilization capacity of sunflower in semi-arid environment

Authors Organisations
  • Muhammad Awais(Author)
    The Islamia University
  • Aftab Wajid(Author)
    University of Agriculture, Faisalabad, Pakistan
    University of California, Davis
  • Muhammad Usman Bashir(Author)
    The Islamia University
  • Muhammad Habib ur Rahman(Author)
    Muhammad Nawaz Sharif University of Agriculture
  • Muhammad Aown Sammar Raza(Author)
    The Islamia University
  • Ashfaq Ahmad(Author)
    University of Agriculture, Faisalabad, Pakistan
  • Muhammad Farrukh Saleem(Author)
    University of Agriculture, Faisalabad, Pakistan
  • Hafiz Mohkum Hammad(Author)
    COMSATS University Islamabad
  • Muhammad Mubeen(Author)
    COMSATS University Islamabad
  • Umer Saeed(Author)
    University of Agriculture, Faisalabad, Pakistan
  • Naveed Arshad(Author)
  • Shah Fahad(Author)
    Huazhong Agricultural University
Type Article
Original languageEnglish
Pages (from-to)17511-17525
Number of pages15
JournalEnvironmental Science and Pollution Research
Issue number21
Early online date08 Jun 2017
Publication statusPublished - 01 Jul 2017
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The combination of nitrogen and plant population expresses the spatial distribution of crop plants. The spatial distribution influences canopy structure and development, radiation capture, accumulated intercepted radiation (Sa), radiation use efficiency (RUE), and subsequently dry matter production. We hypothesized that the sunflower crop at higher plant populations and nitrogen (N) rates would achieve early canopy cover, capture more radiant energy, utilize radiation energy more efficiently, and ultimately increase economic yield. To investigate the above hypothesis, we examined the influences of leaf area index (LAI) at different plant populations (83,333, 66,666, and 55,555 plants ha−1) and N rates (90, 120, and 150 kg ha−1) on radiation interception (Fi), photosynthetically active radiation (PAR) accumulation (Sa), total dry matter (TDM), achene yield (AY), and RUE of sunflower. The experimental work was conducted during 2012 and 2013 on sandy loam soil in Punjab, Pakistan. The sunflower crop captured more than 96% of incident radiant energy (mean of all treatments), 98% with a higher plant population (83,333 plants ha−1), and 97% with higher N application (150 kg ha−1) at the fifth harvest (60 days after sowing) during both study years. The plant population of 83,333 plants ha−1 with 150 kg N ha−1 ominously promoted crop, RUE, and finally productivity of sunflower (AY and TDM). Sunflower canopy (LAI) showed a very close and strong association with Fi (R 2 = 0.99 in both years), PAR (R 2 = 0.74 and 0.79 in 2012 and 2013, respectively), TDM (R 2 = 0.97 in 2012 and 0.91 in 2013), AY (R 2 = 0.95 in both years), RUE for TDM (RUETDM) (R 2 = 0.63 and 0.71 in 2012 and 2013, respectively), and RUE for AY (RUEAY) (R 2 = 0.88 and 0.87 in 2012 and 2013, respectively). Similarly, AY (R 2 = 0.73 in 2012 and 0.79 in 2013) and TDM (R 2 = 0.75 in 2012 and 0.84 in 2013) indicated significant dependence on PAR accumulation of sunflower. High temperature during the flowering stage in 2013 shortened the crop maturity duration, which reduced the LAI, leaf area duration (LAD), crop growth rate (CGR), TDM, AY, Fi, Sa, and RUE of sunflower. Our results clearly revealed that RUE was enhanced as plant population and N application rates were increased and biomass assimilation in semi-arid environments varied with radiation capture capacity of sunflower


  • leaf area index, crop growth rate, leaf area duration, phenology, fraction of intercepted radiation, photosynthetically active radiation, Photosynthetically active radiation, Phenology, Leaf area duration, Fraction of intercepted radiation, Crop growth rate, Leaf area index