Effect of seed priming with silicon on growth, yield and nutrient uptake of maize under water-deficit stress

Drought is one of the major abiotic stresses reducing productivity of field crops including maize. Silicon (Si) has been known to enhance plant tolerance against various biotic and abiotic stresses. The objective of this study was to evaluate the effects of seed priming of maize with Si on growth, yield, physiological traits and nutrient uptake under different soil moisture regimes. Completely randomized design with factorial arrangement was employed where treatments consisted of three Si doses (0, 1 and 2 mM) and three soil moisture regimes (100%, 75% and 50% field capacity [FC]). Si at 1 mM significantly increased growth and grain yield (similar to 38%) of stressed plants compared with the control, and these values did not significantly change when Si dose was increased to 2 mM. At 75 days after sowing, 1 mM Si at 50% FC increased the actual photochemical efficiency of photosystem II by 33% and the electron transport rate by 31% compared with the control. Silicon significantly reduced the amount of proline accumulation and increased total soluble sugar content at 50% FC. There was no clear increase/decrease in the contents of N, P, K, Ca and Mg in shoot and grain of Si-treated plants under water-deficit stress, except that N content in shoot was significantly increased with the addition of 1 mM Si. Priming seed with 1 mM Si was optimum in improving most of the studied parameters under water-deficit stress, and could offer perspectives for using it as the recommended dose for maize.