فهرست نشریات علمی دسترسی آزاد ایران

This study investigated the physiological effects of Pirimicarb insecticide application on early-stage rapeseed (Brassica napus L. cv. Hyola 401) plants. Field-grown plants at the 2-4 leaf stage received foliar applications of Pirimicarb (500 mg L⁻¹) or distilled water (control) and were subsequently maintained under controlled greenhouse conditions. Physiological measurements conducted 72 hours post-treatment revealed significant increases in total phenolic compounds (+37.4%, P=0.008) and chlorophyll b content (+30.4%, P=0.006) in treated plants. No significant changes were observed in hydrogen peroxide (H₂O₂) levels (+21.1%, P=0.358), malondialdehyde (MDA) concentrations (−14.0%, P=0.086), chlorophyll a (−5.1%, P=0.591), total chlorophyll (+0.8%, P=0.924), or carotenoids (−9.3%, P=0.574). Correlation analysis (n=8 replications) demonstrated a strong positive relationship between phenolic compounds and chlorophyll b (r=0.902, P=0.002), suggesting coordinated metabolic regulation. Strong correlations among core photosynthetic pigments indicated maintained functional integrity of the photosynthetic apparatus. These findings demonstrate that early-stage rapeseed plants respond to Pirimicarb exposure through specific metabolic adjustments involving phenolic biosynthesis and chlorophyll b accumulation, without evidence of oxidative damage or photosynthetic impairment. The results support continued integration of Pirimicarb in integrated pest management systems for rapeseed cultivation.