Growth, Water Relation and Physiological Responses of Eggplant (Solanum melongena L.) under Different Olive Mill Waste Water Levels

Eggplant (Solanum melongena L.) is an important traditional crop, cultivated worldwide.Olive mill wastewater (OMW) is an important olive oil extraction byproduct due to its high concentration of different valuable compounds.Three eggplant cultivars were evaluated under different concentrations of olive mill wastewater.Seedlings were treated with four OMW levels (control, 25% OMW, 50% OMW and 100% OMW).Eggplant cultivars expressed different physiological responses when irrigated with OMW at different levels.Many physiological parameters such as growth, stomatal conductance, transpiration, relative water content, relative growth rate, stem diameter and chlorophyll content were examined.It has been found that many of these responses were adversely affected when plants were irrigated with OMW.Unexpectedly, the water status of eggplants was not affected by the different levels of OMW as plants maintained transpiration rate similar to the control values.Our findings clearly suggest that the physiological responses of eggplant to OMW vary among cultivars.However, the ability of plants to absorb water were not affected by OMW.We recommend that the sensitivity of the eggplant cultivars to OMW be taken into consideration before irrigating eggplants with OMW.