Effects of shading and plant density on leaf growth of Viciafaba

SUMMARY Faba beans ( Viciafaba cv. Maris Bead) were grown in the field at densities of 20 and 60 plants m ‐2 and under zero, 34 and 56% reduction in incoming solar radiation. Measurements of the area of individual leaves were made every two days. Rates of leaf appearance and the duration of expansion of a leaf were virtually unaffected by the experimental treatments. Leaves required approximately 200 o C days (above 1 o C) from appearance to full expansion. Shading consistently increased specific leaf area but decreased leaf weight only at the greater shading level. At low density leaves were largest under 34% shade and smallest under 56% shade, but at high density there were no significant differences in leaf size.