Increased soybean tolerance to water deficiency through biostimulant based on fulvic acids and Ascophyllum nodosum (L.) seaweed extract

• Published in: Plant physiology and biochemistry 2021-01, Vol.158, p.228-243
• Main Authors: do Rosário Rosa, Vanessa, Farias dos Santos, Anna Luiza, Alves da Silva, Adinan, Peduti Vicentini Sab, Mariana, Germino, Gabriel Henrique, Barcellos Cardoso, Flávio, de Almeida Silva, Marcelo
• Format: Article
• Language: English
• Subjects: Abiotic stress; Anti-stress effect; Antioxidant activity; Ascophyllum - chemistry; Benzopyrans - pharmacology; Bioprotection; Dehydration; Gas exchanges; Glycine max (L.) merrill; Glycine max - physiology; Plant Extracts - pharmacology; Seaweed - chemistry; Water
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2020.11.008

To meet the growing demand for soybean it is necessary to increase crop yield, even in low water availability conditions. To circumvent the negative effects of water deficit, application of biostimulants with anti-stress effect has been adopted, including products based on fulvic acids and Ascophyllum nodosum (L.) seaweed extracts. In this study, we determined which formulation and dosage of a biostimulant is more efficient in promoting the recovery of soybean plants after stress due to water deficit. The experiment was conducted in a greenhouse, in a double-factorial randomized block design with two additional factors, four repetitions and eleven treatments consisting of three biostimulant formulations (F1, F2 and F3), and three dosages (0.25; 0.50 and 1.0 kg ha−1); a control with water deficit and a control without water deficit. Soybean plants were kept at 50% of the pot's water capacity for three days, then rehydrated and submitted to the application of treatments with biostimulant. After two days of recovery, growth, physiological, biochemical and yield parameters were evaluated. All plants that received the application of the biostimulant produced more than the water-stressed control plants. The biostimulant provided higher photosynthetic rates, more efficient mechanisms for dissipating excess energy and higher activities of antioxidant enzymes. Plants treated with biostimulant were more efficient in the recovery of the metabolic activities after rewatering, resulting in increased soybean tolerance to water deficit and reduced yield losses. The best result obtained was through the application of formulation 2 of the biostimulant at a dosage of 0.25 kg ha−1. [Display omitted] •Climate changes has affected the rain regime and impaired the productivity of crops like soybean.•The water deficit reduces the photosynthetic activity of plants, affecting crops yield and increasing the production of ROS.•To minimize the damage caused by drought, agricultural practices have been adopted, such as the application of biostimulants.•Biostimulants have an anti-stress effect, improving the development and yield of plants subjected to water deficit.•The biostimulant improved the antioxidant efficiency and protective mechanisms of soybean, reflected in higher productivity.