The growth impairment of salinized fenugreek (Trigonella foenum-graecum L.) plants is associated to changes in the hormonal balance

Incorporation of compost and biochar enhances yield and medicinal compounds in seeds of water-stressed Trigonella foenum-graecum L. plants cultivated in saline calcareous soils

BACKGROUND

The combination of compost and biochar (CB) plays an important role in soil restoration and mitigation strategies against drought stress in plants. In the current study, the impact of CB was determined on the characteristics of saline calcareous soil and the productivity of fenugreek (Trigonella foenum-graecum L.) plants. The field trials examined CB rates (CB0, CB10 and CB20 corresponding to 0, 10, and 20 t ha‒1, respectively) under deficit irrigation [DI0%, DI20%, and DI40% receiving 100, 80, and 60% crop evapotranspiration (ETc), respectively] conditions on growth, seed yield (SY), quality, and water productivity (WP) of fenugreek grown in saline calcareous soils.

RESULTS

In general, DI negatively affected the morpho-physio-biochemical responses in plants cultivated in saline calcareous soils. However, amendments of CB10 or CB20 improved soil structure under DI conditions. This was evidenced by the decreased pH, electrical conductivity of soil extract (ECe), and bulk density but increased organic matter, macronutrient (N, P, and K) availability, water retention, and total porosity; thus, maintaining better water and nutritional status. These soil modifications improved chlorophyll, tissue water contents, cell membrane stability, photosystem II photochemical efficiency, photosynthetic performance, and nutritional homeostasis of drought-stressed plants. This was also supported by increased osmolytes, non-enzymatic, and enzymatic activities under DI conditions. Regardless of DI regimes, SY was significantly (P ≤ 0.05) improved by 40.0 and 102.5% when plants were treated with CB10 and CB20, respectively, as similarly observed for seed alkaloids (87.0, and 39.1%), trigonelline content (43.8, and 16.7%) and WP (40.9, and 104.5%) over unamended control plants.

CONCLUSIONS

Overall, the application of organic amendments of CB can be a promising sustainable solution for improving saline calcareous soil properties, mitigating the negative effects of DI stress, and enhancing crop productivity in arid and semi-arid agro-climates.

Beneficial Microbes and Molecules for Mitigation of Soil Salinity in Brassica Species: A Review

Salt stress results from excessive salt accumulation in the soil can lead to a reduction in plant growth and yield. Due to climate change, in the future climatic pressures, changed precipitation cycles and increased temperature will increase the pressures on agriculture, including increasing severity of salt stress. Brassica species contains oilseed and vegetable crops with great economic importance. Advances in understanding the mechanisms of salt stress in Brassica plants have enabled the development of approaches to better induce plant defense mechanisms at the time of their occurrence through the use of beneficial microorganisms or molecules. Both endophytic and rhizospheric microbes contribute to the mitigation of abiotic stresses in Brassica plants by promoting the growth of their host under stress conditions. In this review we summarized so far reported microorganisms with beneficial effects on Brassica plants and their mode of action. Another approach in mitigating the harmful effect of soil salinity may involve the application of different molecules that are involved in the stress response of Brassica plants. We reviewed and summarized their potential mode of action, methods of application and pointed out further research directions.

Interactive effects of salinity and silicon application on Solanum lycopersicum growth, physiology and shelf-life of fruit produced hydroponically

BACKGROUND

Using water with high salinity for plant fertigation may have detrimental effects on plant development and total yield and on the quality of the crop produced. As a possible means to alleviate the negative effects of salinity, silicon (Si) can be incorporated in the nutrient solution supplied to plants. In the present study, hydroponically grown tomato (Solanum lycopersicum Mill.) plants were subjected to two different salinity levels (0 and 50 mmol L^-1 NaCl) with and without the application of Si (0 and 2 mmol L^-1 K₂ SiO₃ ) in order to evaluate its possible positive impact on mitigation of salinity stress-induced symptoms. An additional experiment was implemented with postharvest Si application (sodium silicate) to investigate effects on the shelf-life of tomato fruit.

RESULTS

Salinity (50 mmol L^-1 NaCl) decreased plant size, total yield and fresh fruit weight while a high percentage of blossom end rot symptoms of tomato fruit was also observed. The application of Si in the nutrient solution counteracted these detrimental effects, generating a higher yield and healthier fruit (lower blossom end rot incidence) compared to the untreated plants (no application of Si). Salinity improved several quality-related traits in tomato fruit, resulting in higher marketability, whereas the addition of Si (pre- and postharvest) maintained fruit firmness following storage thereby increasing the shelf-life of tomato fruit.

CONCLUSIONS

These findings indicate that Si application (pre- and postharvest) could provide an effective means of alleviating the unfavorable effects of using low-quality water in plant fertigation on tomato plant development, fruit yield and post-harvest quality, through increased fruit firmness. © 2019 Society of Chemical Industry.