Growth, leaf ion concentration, stomatal behaviour and photosynthesis of bean (Phaseolus vulgaris L.) irrigated with saline water

The aim of this study was to determine the effects of soil salinity on plant growth, gas exchange, and leaf nutrients of a salt sensitive species, green shelled bean (Phaseolus vulgaris L. cv. Lingua di fuoco). Plants were grown in pots under greenhouse conditions and irrigated with water containing one of three different salinity levels: 0.39 (tap water control), 10 or 20 dS m-1; salinity levels were adjusted by adding CaCI2 to the irrigation water. Leaf area development, stomatal conductance, transpiration, photosynthesis, leaf ion concentrations, and plant dry weight were measured. Salinity stress severely reduced plant growth and leaf area development in bean. and increased leaf senescence. Plants exposed to salinity stress had higher concentrations of Ca2+, and lower concentrations of K+, in new leaf tissue than unstressed plants. Photosynthesis was also reduced in salt stressed plants, and this reduction was due to limitations on stomatal conductance