Effects of Preemergence Applied Herbicides on Pampas Grass

Abstract

Pampas grass seedlings in 72-cell pack containers were transplanted into containers with a root observation window (17.8 × 10.2 cm) and treated with selected preemergence applied herbicides. Root numbers were counted in the upper and lower 8.9 cm of the viewing window until 16 days after treatment (DAT) when the windows became full of roots. Root growth in both the upper and lower window was suppressed with application of Factor 65 WG and Pendulum 60 WDG at the X and 2X rates at 16 DAT. Ronstar 2G and Pendulum 2G at the recommended rates and nontreated control plants had similar root numbers at 16 DAT. At 16 DAT, the greatest number of club roots formed on plants treated with the dinitroaniline herbicides; Pendulum 2G, Pendulum 60 WDG, and Factor 65 WG. Shoot growth was not affected by treatment.