Growth and yield of spinach as affected by silicon and fulvic acid under salt stress

Abstract EN

Two pots experiments were conducted at Abu Hummus, El- Beheira Governorate, Egypt, during the successive winter seasons of 2019 and 2020 to investigate the effect of fulvic acid and silicon in elevating the negative impact of salinity on vegetative growth, yield and chemical composition of spinach under different salinity levels.

Each experiment includes 20 treatments which were the combinations between four salinity levels (Tap water, 1500, 3000 and 4500 ppm) and soil application treatments of fulvic (1.5 and 3.0 gm / L), silicon (1.5 and 3.0 mM) and distilled water as control treatment.

The experiments were carried out as randomized complete block design (RCBD) in split plot system with three replicates.

Whereas, the salinity levels arranged in the main plots while the soil application treatments of fulvic and silicon were randomly located in the sub-plots.

Generally, the obtained results indicated, that all tested characters decreased with increasing salinity levels.

The reduction rate on any character varied depending on the imposed level of salinity stress.

Adding fulvic acid and silicon in all concentrations showed significant effect in improving all studied traits as compared to the control treatment, in both seasons.

Application of silicon at 3 mM recorded the highest values of plant height, plant fresh weight, plant dry weight, number of leaves per plant, nitrogen, phosphorus, potassium, protein and total chlorophyll contents and reduced the hazard effect of nitrate and total oxalate comparing to the other treatments in both seasons.

The combined treatment of silicon (Si) at the rate of 3 mM and salinity level at zero gave the highest values of the most tested parameters.

The outcome of this research recommends the opportunity of adding silicon (Si) or fulvic acid (FA) to enhance spinach plants and minimize the harmful effect of salinity.