Enhancing Actara and Bayleton Detoxification in Greenhouse Cucumbers Using Plant Growth Stimulants

Abstract Crops cultivated in protected environments often require pesticide applications, which can increase the risk of pesticide residues due to short harvest cycles and slow detoxification. This study tested the efficacy of Biohumus and Fertimicro for accelerating the dissipation of two commonly used pesticides, Actara (thiamethoxam) and Bayleton (triadimefon), in greenhouse-grown cucumbers. Biohumus, an organic amendment rich in beneficial microbes and humic substances, and Fertimicro, a microfertiliser containing essential nutrients, were applied alongside pesticides. Residue levels were analysed 1, 3 and 5 days after treatment. Both biostimulants significantly enhanced pesticide degradation compared to untreated controls. The study revealed significant pesticide residues in cucumber fruits one day after treatment. In the days following spraying, intensive detoxification of pesticide residues occurred, leading to a significant decline in Bayleton and Actara residue levels. Stimulant-based solutions significantly enhanced pesticide detoxification compared to water-based treatments. Without biostimulants, Ac-tara residues in cucumber fruits exceeded the MRL (maximum residue limit) fourfold, even three days after spraying (PHI – pre-harvest interval). Biostimulant application reduced Actara residues to 0.08 ± 0.01 mg/kg with Biohumus and within the limit with Fertimicro (0.05 mg/kg, p = 0.0044). A similar trend was observed for Bayleton: by day 5 (PHI), Biohumus- and Fertimicro-treated fruits met the MRL (0.5 mg/kg), whereas untreated fruits exceeded the limit by 1.6 times ( p = 0.00051).