Growth, fruit yield, quality, and water productivity of grape tomato as affected by seed priming and soil application of silicon under drought stress

Abstract

Drought has been identified as a major threat restricting crop production worldwide. Silicon (Si), a beneficial element, has a proven role in enhancing plant tolerance against various biological and environmental stresses, especially drought. Two polyhouse experiments were conducted to evaluate the effect of seed priming and soil application of Si on growth, fruit yield, quality, and water productivity of grape tomato (Solanum Lycopersicon L. var. cerasiform) under drought stress. In the first experiment, Si in the form of monosilicic acid (MSA [H4SiO4]) was applied as a seed priming material in five doses (0, 0.063, 0.125, 0.25, and 0.5 mM) under three soil moisture regimes (50%, 75%, and 100% field capacity [FC]). The second experiment consisted of five MSA doses applied as soil incorporation (0, 75, 150, 300, and 600 kg ha–1) under the same soil moisture regimes used in the first experiment. The results revealed that fruit yield and irrigation water productivity were severely affected by soil moisture deficit at 50% FC, while fruit quality was better at this soil moisture level. Fruit yield was reduced by 95% at 0 mM MSA priming dose at 50% FC compared with fruit yield at 0.25 mM MSA priming dose at 100% FC in the first experiment. In the second experiment, soil incorporation of MSA at 300 kg ha–1 in combination with 100% FC maximized fruit yield, which was reduced by 96% at 0 kg ha–1 MSA dose in combination with 50% FC. Exogenous application of MSA at 0.25 mM as a seed priming material and 300 kg ha–1 as soil incorporation (60 kg ha–1 soluble Si) also resulted in better fruit yield and irrigation water productivity at 75% FC. Priming seeds of grape tomato with MSA at 0.25 mM or soil incorporating with 300 kg ha–1 could be recommended to enhance fruit yield of grape tomato grown under soil moisture regime fluctuating between sufficient (100% FC) and moderate soil moisture availability (75% FC).