Role of Marine Algae Extracts in Water Stress Resistance of Onion Under Semiarid Conditions

Abstract

Availability of water for food production is a global concern; thus, increasing water productivity has been become a necessary. Deficit irrigation is a good strategy to increase water use efficiency, but it may affect negatively on plant physiology and crop productivity. Little is known about the effect of marine algae extracts on water stress resistance and yield of onion grown on semiarid regions. Therefore, field experiments were conducted in 2018 and 2019 growing seasons to study the effect of foliar application of marine alga (Amphora ovalis) extracts (at rate of 0, 3, 6 or 9%) on onion grown under normal irrigation (80% of available soil water) or water stress (50% of available soil water). The field experiments were laid out in a split-plot design with four replicates. The highest dose of algal extract sprayed on onion grown under water stress significantly (P < 0.05) increased N, P, and K uptake by 116, 113, and 93% compared to the unsprayed plants. The application of 9% algal extract for onion grown under water stress significantly (P < 0.05) increased the bulb yield by 67 and 102%, respectively, in 2018 and 2019 growing seasons. Water stress reduced the chlorophyll production as a result of directing most of plant's energy to produce water-resistant materials such as proline and phenols. Algal extract reduced the negative effects of water stress and caused significant increases in onion growth and yield.

Potential of Seaweed Extract on Growth, Physiological, Cytological and Biochemical Parameters of Wheat (Triticum aestivum L.) Seedlings

“…These findings show that the plants primed with seaweed extracts were subjected to less stress than the control plants, resulting in healthy growth. The results of the current study are consistent with those of Almaroai and Eissa (2020) and Campobenedetto et al (2021). The fact that most of the plant's energy is directed to the biosynthetic route of macromolecules like carbohydrates and proteins may explain the lower proline accumulation in wheat seedlings.…”

Effects of Seaweed Extracts on the Growth, Physiological Activity, Cane Yield and Sucrose Content of Sugarcane in China

“…Our results determined at seedling and elongation stages showed that spraying SEs could significantly increase the SPAD value of sugarcane leaves, which indicated that the application of SEs increased chlorophyll content in leaves (Figure 2), which is also supported by other reports (Lingakumar et al, 2004;Ali et al, 2016Ali et al, , 2019. This might be due to the existence of betaine, amino acids, and other active substances in SEs that inhibit the degradation of chlorophyll (Blunden et al, 1996), Seaweed extracts also contain magnesium, which is necessary for chlorophyll synthesis (Almaroai and Eissa, 2020).…”

“…Our results determined at seedling and elongation stages showed that spraying SEs could significantly increase the SPAD value of sugarcane leaves, which indicated that the application of SEs increased chlorophyll content in leaves ( Figure 2 ), which is also supported by other reports ( Lingakumar et al, 2004 ; Ali et al, 2016 , 2019 ). This might be due to the existence of betaine, amino acids, and other active substances in SEs that inhibit the degradation of chlorophyll ( Blunden et al, 1996 ), Seaweed extracts also contain magnesium, which is necessary for chlorophyll synthesis ( Almaroai and Eissa, 2020 ). Our results showed that spraying SEs had a significant effect on the photosynthetic rate of sugarcane leaves which were consistent with those of SPAD, and these resulted in a stronger ability of plants to maintain a better photosynthetic performance ( Santaniello et al, 2017 ).…”

“…SEs increased the absorption of soil nutrients by plants, stimulated the growth of crops, increased yield ( Renaut et al, 2019 ; Boukhari et al, 2020 ), and enhanced plant resistance to biotic ( Machado et al, 2014 ; Ben Salah et al, 2018 ) and abiotic stress ( Bradáčová et al, 2016 ; Cabo et al, 2019 ; Khompatara et al, 2019 ). For example, SEs sprayed on onion grown under water stress significantly increased N, P, and K uptake by 116, 113, and 93% compared to the unsprayed plants ( Almaroai and Eissa, 2020 ). Another study found that SEs increased chlorophyll content by increasing the biogenesis of chloroplasts and reducing chlorophyll degradation, which was due to the up-regulated genes associated with photosynthesis, cell metabolism, stress response and S and N metabolism in Brassica napus L. ( Jannin et al, 2013 ).…”

Effects of brown seaweed extract, silicon, and selenium on fruit quality and yield of tomato under different substrates

“…Previous studies have shown that the application of seaweed extract was beneficial to crop growth and development. The researchers reported that spraying seaweed extract had positive impacts on the accumulation of mineral elements and photosynthesis pigments [ 17 ]. Foliar spraying seaweed extract on onion reportedly increased the absorption of N, P, and K by 116, 113, and 93% in comparison with the control plants [ 17 ].…”