Growth and photosynthetic characteristics of lucerne (Medicago sativa L.) genotypes as influenced by salinity of irrigation water

Lucerne cv. RL 88, T 9 and Anand 2 were irrigated with four levels of saline water (0.8, 4, 8, 12 dSm⁻¹) and the effect on growth and photosynthetic efficiency were examined. Leaf photosynthesis rate (pn) was maintained in Anand 2 but declined in RL 88 at higher salinity level. T 9 showed an increase in Pn at 4 dSm⁻¹. The reduction in Pn at higher salinity level was the result of increased stomatal resistance and thereby low intercellular CO₂ concentration. RL 88 and Anand 2 maintained tlie herbage yield with increasing levels of salinity. In cv. T9 however, the herbage yield decreased by 57% at 12 dSm⁻¹ in comparison to control.