Estimation of effectivity of new growth regulators on winter wheat productivity and quality

Triazole derivatives are powerful agronomic tools that regulate multiple plant processes. In wheat, they help balance veget a tive and reproductive growth, enhance tolerance to abiotic and biotic stresses, and support stable, high yields with improved grain quality. Their dual functionality as growth regulators and broad-spectrum fungicides enables integrated, resource-efficient pr o grams that couple crop protection with physiological stimulation. In this study, seeds from five winter wheat varieties (1.000 grains per treatment) were primed in aqueous solutions of two triazole-type compounds, CA-64 and CA-79, at 0.01%, 0.02% and 0.04%. Soaking lasted 24 hours under standard protocols for plant growth stimulants; water-soaked seeds served as controls. Triazole - based seed priming is increasingly used to fine-tune early crop physiology, yet concentration-response windows and genotype specificity remain underdefined for winter wheat. Two triazole agents have been evaluated across varieties and me a surement systems and a narrow, repeatable stimulatory window was found at 0.01–0.02% with a consistent toxicity threshold at 0.04%. Within the effective range, CA-79 outperformed CA-64 for photosynthetic status (SPAD and calculated chlorophyll), grain yield, yield components (grain weight per main spike, total grain weight per plant, thousand-grain weight (TGW) and grain quality ) . Responses were robust across years and genotypes, with the largest advantage of CA-79 at 0.02%, particularly in MIP Feeriya and the western ecotypes (MV Nador, MV Menrot), while still conferring clear gains in local varieties (Pozitsia Odeska, Tenor). CA-79 (0.02%) reliably increased protein and wet gluten and shifted the glutenin profile toward higher HMW fractions without inflating LMW glutenins , which was an advantageous pattern for baking strength. CA-64 at 0.02% was a safe, positive alternative, though the magnitude of improvement was generally smaller. At 0.04%, both agents depressed photosynthetic indic a tors, yield, and quality indices; HMW glutenins declined most, underscoring a clear toxicity boundary that should be avoided. Genotype conditioning was evident. Local genotypes showed predictable uplift at 0.02% (CA-79 preferred, CA-64 dependable as fallback). Western ecotypes benefited at 0.01–0.02%, with CA-79 providing a broader margin; doses above 0.02% are not re c ommended. Operationally, CA-79 at 0.02% is the default choice for maximal, balanced improvements in photosynthetic capac i ty, yield, and baking quality. Where risk aversion or seed-lot sensitivity warrants caution, 0.01% offers a gentler yet significant uplift. CA-64 (0.01–0.02%) remains a practical second line when access or regulatory status limits CA-79. 0.04% should be avoided for both compounds. These findings delineate concentration-genotype operating zones for triazole priming in winter wheat and highlight CA-79 as the leading option at 0.02% concentration. Ongoing work will extend the assessment to micron u trient enrichment (Fe, Zn, Cu, Mn) to link physiological stimulation with nutritional quality gains.