The Effect of Shading at Different Growing Stage on the Spike Number and the Character of Spike in Wheat Plants

Abstract

The effect of shading at different growing stage on wheat was examined to confirm the stage when the spike number and the character of spike were determined. Spike number decreased by shading to full heading date. T₃ showed a marked decrease in the spike number compared with M, T₁ or T₂. Spikelet number decreased to floret differentiation stage of tillers by shading. Since floret differentiation stage was delayed in T₃ than in comparison with that in M, T₁ or T₂, spikelet number of T₃ decreased later than M, T₁ or T₂ by shading. Sterile spikelet number of tillers decreased to full heading date by shading. Grain number per spikelet of tillers was affected by shading from two weeks before full heading to ripening stage. Grain weight of tillers was affected by shading at ripening stage.