Dynamic changes and quantification of winter wheat leaf area

Based on field experiments，dynamic changes of leaf area，specific leaf area(SLA)and dry leaf ratio are described and quantified．After wintertime，specific leaf area decreases linearly with logarithmic relative development stage (RDS)and SLA=-21．07×1n(RDS)+19．427．The maximum and minimum specific leaf area is 40 m²／kg and 19m²／kg，respectively．Dry leaf ratio(DR)has parabola relationship with relative development stage and DR=2．142×RDS -1．8001× RDS +0．6571．This study provides a new method and bases for the simulation of winter wheat leaf area in the crop mode1．