The effects of reduced doses and application timing of metribuzin on redroot pigweed (Amaranthus retroflexus L.) and wild mustard (Sinapis arvensis L.)

Authors: İBRAHİM KAHRAMANOĞLU, F. NEZİHİ UYGUR

Abstract: Minimum doses of metribuzin that provide satisfactory control (>90%) of redroot pigweed (Amaranthus retroflexus L.) and wild mustard (Sinapis arvensis L.), 2 troublesome weeds of potato crops planted in spring and autumn, respectively, were assessed. Greenhouse experiments were conducted using 100%, 80%, 60%, 40%, 20%, and 0% of the registered dose (525 g a.i. ha^{-1}) of metribuzin applied to the weeds grown in plastic pots. Dry weight data from the experiments were subjected to nonlinear regression analysis and the effective doses of metribuzin that caused a 90% reduction in dry weight (ED_{90}) were estimated. Metribuzin at doses of 240.8 and 293.2 g a.i. ha^{-1} resulted in a 90% reduction in the dry weight of A. retroflexus when applied at the BBCH 12-15 and BBCH 16-19 growth stages, respectively. Metribuzin at doses of 183.7 and 256.2 g a.i. ha^{-1} provided 90% control of S. arvensis at the BBCH 12-15 and BBCH 16-19 growth stages.

Keywords: Dose-response curve, metribuzin, minimum dose, satisfactory control efficiency, weed development stage

Full Text: PDF