Alternative weed control in large container-grown ornamentals.

摘要

Experiments were conducted to evaluate alternative weed control methods in horticultural systems. Twenty-five prostrate spurge (Euphorbia supina Raf.) seed were seeded into each 57-L ‘Natchez’ crape myrtle (Lagerstroemia indica L. x faurei L. ‘Natchez’) container and 25 bittercress (Cardamine hirsuta L.) seed were seeded into each 57 L ‘Nellie R. Stevens’ holly ( Ilex L. x ‘Nellie R. Stevens’). Treatments included: 2G oxyfluorfen at 2.18 kg ai/ha + 1G oryzalin at 1.09 kg ai/ha (Rout 3G) as a broadcast application, 2G oxyfluorfen at 2.18 kg ai/ha + 1G oryzalin at 1.09 kg ai/ha as an individual container application, copper hydroxide coated fabric disks fitted around the plant stem, 5 cm thick mulches of recycled newspaper pellets, copper hydroxide coated recycled newspaper pellets, ground kenaf, waste tire crumbles, wheat straw, oat straw, cereal rye, and paper mill sludge, a hand-weeded control, and weedy control. Treatments that performed best at the Poplarville location were fabric disks, recycled newspaper pellets with copper hydroxide, and shredded rubber tire with no more than 29, 40, and 24% of the pot covered by weeds at any rating date, respectively. At the Auburn location, no more than 19% coverage was reported at rating dates prior to 360 DAT with recycled newspaper pellets with copper hydroxide. In the holly experiment no more than 34% coverage was reported at any rating date. The fabric disks did not perform as well at the Auburn location in either experiment, with as much as 34% coverage in the crape myrtle experiment and 80% in the holly experiment. The shredded rubber tires exhibited excellent control at all rating dates, with no more than 18% pot coverage at any rating in either experiment.; Alternative mulches are commonly utilized in landscape practices, but little is known about their effect on herbicide efficacy and mobility. Therefore, experiments were conducted to evaluate the mobility of three commonly used herbicides applied over various mulching systems. Treatments included: three herbicides (pendimethalin, isoxaben, or metolachlor) and four mulches (bare soil, recycled newspaper pellets, pine bark, or pine straw). Compared with pendimethalin and isoxaben, metolachlor had greater leaching potential. All mulches decreased leaching regardless of herbicide used and use of recycled newspaper pellets without copper hydroxide resulted in the greatest reduction.; Allelopathic activity of kenaf (Hibiscus cannabinus L.), wheat (Triticum aestivium L.), oat (Avena sativa L.), and cereal rye (Secale cereale L.) straw as well as shredded rubber tires and recycled newspaper pellets without copper hydroxide were examined on prostrate spurge, bittercress and lettuce ( Lactuca sativa v. crispa). Few consistent allelopathic effects were exhibited by the mulches on any of the three species evaluated.