BIOSTIMULANT EFFECTS OF A COPPER–GLYCYRRHIZIC ACID SUPRAMOLECULAR COMPLEX (CUPROTGK) ON GRAIN SEED GERMINATION AND WINTER WHEAT FIELD PRODUCTIVITY

Sharp climatic changes across Central Asia have intensifiedphytopathological pressure on grain crops, including wheat, while widely used importedfungicides remain costly and prone to inducing pathogen adaptation, motivating interest inlocally sourced, environmentally benign biostimulants. This study evaluated thebiostimulant activity of CuproTGK, a copper supramolecular complex of technicalglycyrrhizic acid extracted from Karakalpakstan-grown licorice (Glycyrrhiza glabra L.)root, on grain seed germination and on winter wheat field productivity. In laboratory trials,seeds of winter wheat (Triticum aestivum L., “Dosliq” variety), sorghum (“Nayman” and“Karlik” varieties), and maize were pre-soaked in a dilute CuproTGK solution and theirwater-absorption dynamics were monitored over 240 hours; treated samples showedincreased water-uptake intensity relative to untreated controls across all four grain samples,with maize showing the largest absolute gain (0.515 g versus 0.400 g per seed lot at 240hours) and sorghum “Nayman” and “Karlik” samples overtaking their respective controlsby the final time point. Under control conditions, wheat grain mass increased by 47.5 ± 3.5%(from 41.7 ± 2.4 mg to 61.5 ± 2.4 mg) over the first 72 hours of imbibition, the period ofmost intensive water uptake. In a three-year field trial (2018–2020) conducted withCuproTechGK and CuproGK preparations on winter wheat at the experimental plots of theInternational Innovation Center for the Aral Sea Region, treatment reduced production costby an average of 17.4 Uzbek soums per centner, increased sales revenue by more than 5.3thousand soums per hectare, reduced production expenditure by 2.5 thousand soums perhectare relative to control, and raised product profitability by 6.8 percentage points. Thesefindings indicate that the CuproTGK complex enhances early seed vigor across multiplegrain species and delivers measurable economic benefit under regional field conditions, supporting its further development as a locally produced biostimulant for stress-prone,saline-soil agriculture in the Aral Sea region.