EFFECTS OF SILICON ON TOMATO GROWN IN SUBSTRATE CULTURE UNDER SALINITY STRESS

This study was carried out to assess the effect of silicon (Si) against salt stress in greenhouse tomato production. Plants were grown in three different media namely perlite, coir, and clinoptilolite and irrigated with nutrient solutions with 2 different salinity levels (2 dS/m:Control and 8 dS/m:Saline) and 2.5 mM/L K2SiO3 [Si(+)] applied to each nutrient solution was compared with the control group which contained no silicon [Si(-)]. Salt was applied to plants three weeks after plantation by adding 65.7 mM/L NaCl to the nutrient solution. Experiment was established according to three-factor split-parcel experiment design and plants were grown for 4 months and 7 trusses were harvested during the production. The results showed that while salinity increased Na concentration in the leaves and adversely affected plant growth and yield, fruit number, leaf K content, plant water consumption and water use efficiency; silicon application to the nutrient solution had a positive impact especially in reducing the negative effects of salt stress in the root zone under saline condition. It was concluded that silicon can be a practical alternative to reduce salt stress and that the use coir bolsters the positive effect of silicon in increasing salt tolerance.