EFFECT OF MANIPULATING NUTRIENT SOLUTION SALINITY ON THE GROWTH OF CUCUMBER CUCUMIS SATIVUS L. GROWN IN NFT

Cucumber plants Cucumis sativus L. grown in NFT at 2.5/8.5 and 8.5/2.5 day/night nutrient solution salinity were compared with those at constant salinities of 2.5 and 8.5 mS cm^-1. Day time and night time were 14 and 10 h. Growth seems to be affected by factors influencing the total water uptake by the plant such as the time and duration of exposure to salinity. Fruit yield per plant was reduced in the same pattern as vegetative growth. The diurnal measurements of the plant water potential showed that the plant water status was rapidly affected by the changes in the root osmoticum. The results show a greater effect of high salinity during the day than during the night, which indicates clearly that salinity acts through its effect on water uptake by the plant.