Phytotoxic effects of selected herbicides on growth and seedling survival of okra (Abelmoschus esculentus L.)

Abstract

A field experiment was conducted during the kharif season to evaluate the phytotoxic effects of commonly used herbicides on crop growth of okra (Abelmoschus esculentus L.). The study assessed the crop response to different weed control treatments, with particular emphasis on herbicide-induced injury symptoms and seedling survival. Visual observations on phytotoxicity parameters such as leaf chlorosis, necrosis, epinasty, hyponasty, wilting, vein clearing, leaf tip burning, and plant mortality were recorded at periodic intervals following herbicide application. The results revealed that application of oxyfluorfen caused severe phytotoxicity, characterized by initial leaf yellowing followed by progressive necrosis and substantial seedling mortality, which increased from 40% at 7 days to 80% by 30 days after application. In contrast, oxadiargyl induced only mild and transient injury symptoms, with limited seedling mortality (10-20%) and gradual crop recovery by 30 days. No epinasty was observed in either treatment, though hyponasty was recorded in oxadiargyl-treated plots. Importantly, pendimethalin and propaquizafop did not induce any visible phytotoxic symptoms, indicating their crop safety when applied at recommended doses. The absence of injury under these treatments may be attributed to their selective mode of action, limited crop uptake, and favorable application timing. Overall, the study demonstrated that oxyfluorfen posed a higher phytotoxic risk to okra, whereas oxadiargyl showed moderate crop tolerance, and pendimethalin and propaquizafop were found to be safe and crop-friendly options. These findings highlight the importance of selecting herbicides based not only on weed control efficacy but also on crop safety for sustainable okra production.