Evaluation of Seaweed Extract Impact on Growth and Yield of Tomato Plants under Salinity Stress Conditions

     This experiment was conducted at the Faculty of Agriculture, AL-Azhar University, Nasr City, Cairo, Egypt during the two winter seasons of 2018-2019 and 2019-2020 to study the effect of saline levels in the diluted agricultural drainage water of 1000, 2000, 3000, 4000 ppm and tap water as a control (300 ppm) and foliar seaweed extract concentrations of 400, 600 , 800 ppm and tap water as a control and their interaction on the growth, yield and fruits quality of tomato (Lycopersicon esculentum L.) Magy hybrid under plastic house conditions. The obtained results showed that plant height, leaf area, fruit fresh weight, size, length and diameter, leaf chlorophyll A, B and carotenoids contents, in addition to total yield as fruit number and weight significantly increased with using the saline level of 1000 ppm and the foliar seaweed extract concentration of 800 ppm. On contrast, fruit contents of T.S.S and dry matter significantly increased with increasing the saline water levels up to 4000 ppm and the seaweed extract concentrations at 800 ppm. Also, the data indicated that fruit content of ascorbic acid significantly increased from using the 2000 ppm level saline water and the concentration of 800 ppm seaweed extract. In this respect, it could be concluded that the application of the seaweed extract concentration at 800 ppm was the most effective to decrease the adverse effect of saline irrigation water on the growth and yield of tomato plants.