Four preemergence herbicide combinations were evaluated for weed control and phytotoxicity on Silverberry (Elaeagnus pungens Thunb.), Spanish bayonet (Yucca aloifolia L.), and Heavenly bamboo (Nandina domestica Thunb.), grown in 3.8 1 (1 gal) containers under commercial nursery conditions. Combinations of Rout (oxytluorfen : oryzalin) and Rout GL (oxytluorfen : alachlor) were applied as granules at 1.12 : 0.56, 2.24 : 1.12 and 4.48 : 2.24 and 1.12 : 1.12, 2.24 : 2.24, and 4.48 : 4.48 kg ai/ha (1.0 : 05, 2.0 : 1.0, and 4.0 : 2.0 and 1.0 : 1.0, 2.0 : 2.0 and 4.0 : 4.0 lb ai/A), resp. Harness (acetochlor) was applied as a foliar spray at 1.68, 3.36 and 6.68 kg ai/ha (1.5, 3.0 and 6.0 lb ai/A) and Zorial (norflurazon) was applied at 1.12, 2.24 and 4.48 kg ai/ha (1.0, 2.0 and 4.0 lb ai/A) as a soil drench. Containers were overseeded with a weed mixture prior to herbicide application and six weeks later to induce extreme weed competition in containers. Harness, Rout GL and Rout provided 90–100% control for up to 14 weeks after application at the highest rates evaluated. Zorial resulted in unsatisfactory weed control. None of the herbicides caused any phytotoxic effects on any of the plants tested.
Texas Agricultural Station Journal Series TA 24241. This research was supported in part by a grant from the Horticultural Research Institute. We gratefully thank Greenleaf Nursery, Inc., El Campo, TX for donation of plant materials and use of their production facilities.
2Research Associate and Associate Professor, resp.