Retraction: Improving boron use efficiency via different application techniques for optimum production of good quality potato (Solanum tuberosum L.) in alkaline soil

Seaweed extract combined with boron promotes the growth of sugar beet by improving the photosynthetic performance under boron deficiency

Biostimulants can improve mineral nutrient effectiveness, but the physiological mechanisms by which seaweed extract, a natural biostimulant, and boron (B) fertilizer promote the growth of sugar beet under B deficiency are not clear. In this study, B and seaweed extract were applied under B-deficiency (0.32 mg B kg-1 soil) and potentially B-deficient conditions (0.69 mg B kg-1 soil), and the growth and photochemical properties of sugar beet seedlings were investigated. The results indicated that B application alone or with seaweed extract promoted sugar beet growth, with the combined application having a significantly enhanced effect. When comparing the two soils with different B content (deficient and moderately deficient), the spray of seaweed extract under the B-deficient condition was more effective. After the addition of seaweed extract, the B content of the shoots and roots increased by 28.56% and 12.64%, respectively, under B deficiency(0.32 mg B kg-1 soil). Furthermore, the content of chlorophyll a (Chla), chlorophyll b (Chlb), and the net photosynthesis rate (Pn) increased by 8.96%, 30.57%, and 13.74%, respectively. The addition of seaweed extract significantly improved the light saturation point (Pm), with a 35.00% increase compared to the control. Additionally, it increased the quantum yield (ETO/CSm) of leaf electron transfer per unit area and reduced the absorption of light energy loss of the PS reaction center (DIO/RC) and per unit area (DIO/CSm), thereby improving photosynthetic performance and significantly increasing aboveground dry matter accumulation by 19.05%. In conclusion, seaweed extract can enhance B absorption, light energy capture and utilization ability. It provides the theoretical evidence for the regulation of B nutrition in sugar beet and the rational application of biostimulants.

Short-term responses of Spinach (Spinacia oleracea L.) to the individual and combinatorial effects of Nitrogen, Phosphorus and Potassium and silicon in the soil contaminated by boron

While of lesser prevalence than boron (B) deficient soils, B-rich soils are important to study as they can cause B toxicity in the field and subsequently decrease crop yields in different regions of the world. We have conducted the present study to examine the role of the individual or combined application of silicon (Si) and NPK fertilizer in B-stressed spinach plants (Spinacia oleracea L.). S. oleracea seedlings were subjected to different NPK fertilizers, namely, low NPK (30 kg ha-2) and normal NPK (60 kg ha-2)], which were also supplemented by Si (3 mmol L-1), for varying levels of B in the soil i.e., 0, 250, and 500 mg kg-1. Our results illustrated that the increasing levels of B in the soil caused a substantial decrease in the plant height, number of leaves, number of stems, leaf area, plant fresh weight, plant dry weight, chlorophyll a, chlorophyll b, total chlorophyll, carotenoid content, net photosynthesis, stomatal conductance, transpiration rate, magnesium content in the roots, magnesium contents in the shoots, phosphorus content in the roots, phosphorus content in the leaves in the shoots, iron content in the roots, iron content in the shoots, calcium content in the roots, and calcium content in the shoots. However, B toxicity in the soil increased the concentration of malondialdehyde, hydrogen peroxide, and electrolyte leakage which were also manifested by the increasing activities of enzymatic [superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX)], and non-enzymatic antioxidants (phenolic, flavonoid, ascorbic acid, and anthocyanin content). B toxicity in the soil further increased the concentration of organic acids in the roots such as oxalic acid, malic acid, formic acid, citric acid, acetic acid, and fumaric acid. The addition of Si and fertilizer levels in the soil significantly alleviated B toxicity effects on S. oleracea by improving photosynthetic capacity and ultimately plant growth. The increased activity of antioxidant enzymes in Si and NPK-treated plants seems to play a role in capturing stress-induced reactive oxygen species, as was evident from the lower levels of oxidative stress indicators, organic acid exudation, and B concentration in the roots and shoots of Si and NPK-treated plants. Research findings, therefore, suggested that the Si and NPK application can ameliorate B toxicity in S. oleracea seedlings and result in improved plant growth and composition under metal stress as depicted by the balanced exudation of organic acids.