The effect of Si on minimizing the implications of water stress on tomato plants

Abstract

W ATER scarcity is a global issue especially in arid regions and rationalizing the use of fresh irrigation water has become necessary to satisfy water needs. The current study investigates using Si to alleviate the implications of water stress on tomato plants grown on a light textured soil. A split-plot experiment was conducted under the field conditions for two successive seasons (2017 and 2018) on tomato under two deficit irrigation levels i.e. 70 and 85% ET c as well as 100% ETc for comparison. Plants were subjected to two levels of silica foliar spray (0 and 0.4 mM). At physiological maturity growth stage, chemical characteristics of tomato fruits as well as total fruit yield were determined. Deficit irrigation decreased contents of chlorophyll A and B in leaves; while increased proline content in plant roots. This consequently decreased tomato fruit yield; while, raised its contents of total dissolved solids and vitamin C. On the other hand, spraying plants with Si raised significantly chlorophyll A and B in leaves and alleviated plant stress by increasing proline content in roots. This increased significantly fruit yield. Irrigation with 85% Et c with Si spray recorded a rather similar fruit yield to those irrigated with 100% Et c. Moreover, Si treatments increased significantly water use efficiency by the crop. Thus, Si spray can take part in saving considered amounts of water that can be used for irrigation of further tomato areas.