Silicon as a mitigator of water deficit stress in radish crop

Abstract

Silicon is the second most abundant element in the Earth's crust and has several beneficial effects on plants, such as increase photosynthetic capacity and improve the architecture of the aerial parts. Water stress negatively affects plant development and, specifically in horticultural species, impacts metabolic processes with consequences on quality and productivity. The aim of this research was to investigate through physiological and biochemical parameters if the use of silicate in place of dolomitic limestone can contribute to the tolerance of radish plants submitted to water deficiency. The experiment was carried out in a greenhouse in Botucatu, Brazil, with radishes of the Apolo variety, distributed in randomized blocks in a 3 × 2 factorial scheme, being three irrigation depths, with high soil moisture at tensions corresponding to 10 kPa (control, FC - field capacity), 20 kPa (MWD - moderate water deficiency), and 30 kPa (SWD - several water deficiency), and two soil correctives, limestone and silicate, totaling six treatments and three repetitions. Irrigation management was performed with tensiometers. The parameters evaluated included biometrics, biomass, growth rates, photosynthesis, enzymatic activity, soluble protein, and proline. Through discussion of the results, it was possible to conclude that the silicate provided tolerance to water stress, reduced the percentage of cracked roots, and increased yield in the radish crop. Therefore the use of silicate in arid areas with low water availability is of great importance.