STUDIES ON SOURCE-SINK RELATIONSHIP OF PLANT ARCHITECTURE MANIPULATION AND BIOMASS PARTITIONING IN WHEAT (Triticum aestivum L.)

The present investigation was carried out at Punjab Agricultural University, Ludhiana during rabi season 2008-2010. Regression analysis showed a significant positive correlation between grain yield and dry biomass of architectural manipulation of source i.e. green leaves (R2=0.89), Blades (R2=0.98) at CRI; green sheath (R2=0.85) and blades (R2=0.83) at tillering stage; blades (R2=0.73) at booting stage; stem (R2=0.75) at Ear emergence; peduncle (R2=0.89)  at flowering; husk (R2=0.89) at anthesis; grain (R2=0.93), sugar (R2=0.76) at milky stage and starch (R2=0.99) at physiological maturity. The architectural manipulation of sink i.e. dry biomass of green leaves (R2=0.86), blades (R2=0.96) at CRI; green sheath (R2=0.83), blades (R2=0.80) at tillering stage; spike (R2=0.87) at anthesis; grain (R2=0.85), starch (R2=0.90) at milky stage and grain (R2=0.85), sugar (R2=0.89) at dough stage showed significantly positive relationship with grain yield. Whereas architectural manipulation of both source and sink also showed significant positive correlation with grain yield and dry biomass of leaf blades (R2=0.89) at CRI; green sheath (R2=0.85), blades (R2=0.81) at tillering; nodal portion (R2=0.98) at ear emergence; spike (R2=0.86) at anthesis; spike (R2=0.82) at grain formation; grain (R2=0.85), starch (R2=0.83) at milky stage, then grain (R2=0.85) at dough stage and starch (R2=0.97) at physiological maturity.  The RMSE values derived from CERES-Wheat for grain 0.5, 0.03, 0.63 and 2.0 at grain formation, milky, dough and physiological maturity stages respectively. These values of RMSE are much smaller than the values derived from Infocrop model.  These results indicated that CERES-Wheat model validate satisfactorily by sink architectural manipulation at reproductive stages.