Surfactants are often added to herbicidal formulations to improve the delivery of the herbicide into plants. In this study a new herbicidal formulation was formed based on the clopyralid with 0.01% gemini surfactant hexanediyl-1,6-bis(dimethylcetylammonium bromide) (16-6-16) as an adjuvant. The increase in the efficiency of the formulation was associated with the formation of a supramolecular surfactant–herbicide complex (SMC), which has improved wetting properties, provides high clopyralid concentration on the leaf surface, and has higher penetrating ability compared to surfactant-free clopyralid solutions. Comparison of the herbicidal action of clopyralid–16-6-16 SMC with two commercial formulations of the same concentration of clopyralid was performed using digital phenotyping of the model weed plant cocklebur (Xanthium strumarium). Based on the spectral indices NDVI (normalized differential vegetation index) and PSRI (plant senescence reflectance index) and key morphological indexes of the leaf angle, plant height, and leaf area, we showed that clopyralid formulations strongly affected the plants and that the strongest and most durable effect was exerted by the clopyralid–16-6-16 SMC formulation.

Speed breeding technologies offer a promising avenue for accelerating crop improvement, yet their application to biennial crops like sugar beet remains constrained by extended generation cycles. This study examined the effects of supplemental phosphorus-potassium (PK) nutrition on the development of two hybrids under a speed-breeding protocol. Plants received one of four nutritional regimes: PK supplementation, potassium (K) supplementation, standard Knop’s solution (KS), or nutrient deficiency (D). Digital phenotyping confirmed that adequate nutrition maintained photosynthetic health, as deficiency significantly reduced NDVI and increased PSRI by 75 days. The most notable, genotype-specific effects were observed in reproductive architecture. PK nutrition significantly increased the median number of flower stalks by 17% in Smart Iberia KWS (21.0 vs. 18.0) and substantially in Dubravka KWS (33.0 vs. 1.0). PK also supported root development, increasing mini-steckling weight by 45–183% under white light. In the generative phase, plants under PK nutrition consistently showed the highest progression to flowering and capsule formation. A consistent increase in median 1000-seed weight of 24–36% was associated with PK treatment. In conclusion, supplementing standard nutrition with phosphorus and potassium enhances key yield-related architectural traits and supports reproductive development in sugar beet under speed-breeding conditions, with the magnitude of response depending on genotype. This provides a practical basis for optimizing mineral nutrition to improve the efficiency of accelerated breeding protocols. This provides a practical basis for optimizing mineral nutrition to improve the efficiency of speed breeding protocols.

Optimizing speed breeding protocols for biennial crops requires matching the vernalization regime with the genetic background. In this study, nine sugar beet genotypes were exposed to 12, 13, 14 or 15 weeks of vernalization and subsequently grown under controlled speed breeding conditions. Survival analysis revealed a threshold-like acceleration of bolting and flowering: 12 and 13 weeks were largely equivalent, whereas 14–15 weeks sharply increased the bolting and flowering hazard rates. Genotypic variation strongly influenced reproductive success and seed yield traits; genotype MARGARITA KWS combined early flowering with the highest seed number (361 seeds per plant) and total seed weight (5.26 g), while genotype 1K073 did not flower under any vernalization duration. A separate mini-steckling root architecture experiment with 11 genotypes showed that slow-release Osmocote fertilizer significantly increased mini-steckling fresh weight, length and width, with the strongest responses in genotypes 1K073, 1K139 and SMART LIENNA KWS. The interaction between genotype and nutrition was significant for mini-steckling fresh weight and width, indicating that optimal nutrition can modulate the expression of genotypic differences. Multivariate analyses (PCA, CVA, Mahalanobis distances) confirmed that vernalization duration had a threshold-type effect and that genotype was the dominant factor for seed traits, whereas nutrition was the main driver of mini-steckling architecture. Overall, these findings suggest that tailoring vernalization duration and nutrition to the genetic background may substantially improve the efficiency of sugar beet speed breeding.