Multifunctional efficacy of pyrolignous acid as an antioxidant and biostimulant for enhanced wheat growth

In this study, a non-synthetic biostimulant (pyrolignous acid, PLA) was prepared as a by-product of pyrolysis of renewable forest resource (Bamboo). The chemical composition, antioxidant activity, biocompatibility of PLA were analysed, and evaluated for wheat growth. A total of 37 organic compounds (phenols, ketones, esters, ethers, alcohols, and aldehydes) were identified using Gas Chromatography–Mass Spectrometry. The PLA exhibited strong antioxidant activity (up to 89.8% DPPH radical scavenging may be attributed to its high phenolic content (48.4%). The PLA formulations were biocompatible with plant growth-promoting rhizobacteria; the bacterial growth increased versus control (up to 10.6%). An increase in wheat yield (up to 20.3%), grain number (up to 21.8%), spike length (up to11.6%), biomass (up to 23.2%) and plant height (up to 11.83%) was observed as a result of PLA treatment via seed priming, foliar application and combination thereof. The effects of priming (P1, overall performance score: 4.7) and combination of priming and foliar (PF1, overall performance score: 4.9) were maximum on yield. Similarly, PLA treatment boosted Chl a (up to 30.4%), Chl b (up to 13.5%), total chlorophyll (up to 27%) and carotenoid (up to 18.6%) in wheat with the highest overall performance score (F3: 4.0) for foliar application. The findings highlight bamboo-derived PLA as a promising organic bio-stimulant for plant health enhancement. The PLA formulations may be offered as a sustainable agricultural input that positively impacts nine (2, 3, 8, 9, 11, 12, 13, 15, 17) Sustainable Development Goals.