Physiological variations in French bean (Phaseolus vulgaris) cultivars as affected by plant density and nitrogen

The result of a field experiment conducted during 1996–97 and 1997–98 revealed that variety PDR 14 had more dry weight, leaf area index, relative growth rate, crop growth rate and seed yield. Varieties HUR 87 and VL 63 being at par also recorded significantly higher net assimilation rate. Leaf area index and crop growth rate were higher at higher plant density (500 × 10³ plants ha⁻¹), whereas dry weight plant⁻¹, net assimilation rate and relative growth rate in general were higher at lower plant density (250 × 103 plants ha⁻¹). Increasing levels of N fertilizer up to 120 kg ha⁻¹ increased dry weight, leaf area index, crop growth rate and relative growth rate, but net assimilation rate increased up to 60 kg N ha⁻¹ only.