Optimizing growth, ionic, physiological case and productivity of sweet pepper under salinity conditions

Salinity experiments were designed to study different performances of treated sweet pepper Baladi cv. under salinity stress (3000 and 6000 ppm NaCl) and application of Ca-gluconate, ATP, K-citrate and Na-benzoate treatments for improving its growth and fruit yield.The results indicated that Increasing levels of salinity resulted in significant decline in vegetative growth, dry matter accumulation and partitioning, flowering, fruiting and fruit yield / plant in the two seasons of growth. Total dry weight/plant and fruit yield/plant were reduced by (33.2 and 17.9%) and (39.7 and 31.6%) (compared with control) during the two seasons of growth due to irrigation with 3000 and 6000 ppm NaCl, respectively. Also, membranes integrity, permeability and selectivity were impaired (measured by EC1/EC2, K/Na values) resulted in excessive uptake and translocation of Na+ and Cl ions vs low conten t of N, P and K with in roots and leaves. Spraying pepper plants with Ca-gluconate, ATP, K-citrate and Na-benzoate, respectively were greatly improved N, P and K content and reduced Na+ and Cl- ions uptake, shift EC1/EC2, K/Na and Na I / Na r values to be in normal case. They were, respectively increased total dry weight and fruit yield by (42. 4, 34.0, 26.6 and 23.1%) and (71.6, 50.7, 42.4 and 35.7%) (means of the two seasons), respectively. In similar trends salinity adversely affected all the studied growth and yield parameters. On the other hand the anti-stress treatments well improved those at 3000 ppm NaCI and ameliorated the adverse effects at higher 6000 ppm NaCl salinity. In this respect, Ca-gluconate and ATP were the most effective one, they increased fruit yield by 20.3 and 4.8% at 3000 ppm NaCl and alleviated the reductions of 6000 ppm NaCl to be only 6.3 and 6.5%, respectively.