Effect of single and tank-mix of selected herbicides on weed control and yield of lowland Rice (Oryza sativa L.) in Lafia, Nasarawa State of Nigeria

Abstract. A field experiment was conducted in 2018 and 2019 in Lafia, Nigeria to determine the effects of single and tank-mix of seven selected herbicides (bispyribac-sodium; cyhalofop-butyl; penoxsulam; pendimenthalin; propanil; thiobencarb) and their mixtures in lowland rice (Oryza sativa L.). Rice grain yield following the single application of bispyribac-sodium post emergence (POST), cyhalofop-butyl POST and penoxsulam POST averaged 30% and 47% greater than the nontreated control in 2018 and 2019, respectively. The application of cyhalofop-butyl plus bispyribac-sodium or thiobencarb plus bispyribac-sodium POST reduced weed density over nontreated control, ranging 98 to 100% in 2018 compared to 88 – 91% reduction in weed density achieved with the application of cyhalofop-butyl alone and the sequential application of PRE pendimenthalin fb POST propanil. Bispyribac-sodium plus cyhalofop-butyl application resulted in the highest rice yield (5.13 and 5.60 t.ha−1) in 2018 and 2019, respectively. Mixtures of bispyribac–sodium with chyhalofop-butyl showed no injury on rice, whereas increased efficacy on weed control as compared with the single application of bispyribac–sodium. We recommend bispyribac-sodium and tank-mixed combination with cyhalofop-butyl to provide a broad spectrum of weed control in lowland rice system in Nigeria.