Effect of Defoliation Treatments and Nitrogen Rates on Yield, Yield Components and Seed Germination of Wheat (Triticum aestivum)

To determine the effect of leaf position and nitrogen rate on the yield and germination of produced seeds of wheat (Triticum aestivum), an experiment was conducted during 2011-2012. Four defoliation treatments (D1=0, D2= flag leaf, D3=all leaves except flag leaf, and D4= all leaves) and two nitrogen rates (N1=0 and N2=150 kg N ha^-1) were imposed on wheat plants. Seed germination was measured for the seeds produced from plants exposed to the defoliation and nitrogen rate treatments. Flag leaf removal significantly reduced seed yield compared with un-defoliated plants with the application of nitrogen treatment (D1N2), but removal of all leaves except flag leaf had no significant seed yield reduction compared with D1N2. Application of nitrogen fertilizer with complete defoliation of plant increased the weight of seedlings produced from those plants. It is recommended to clean the seeds produced from plants exposed to complete defoliation due to lower seed germination and vigor.