Title: Herbicide Effects During Leatherleaf Fern Bed Establishment
Abstract: Abstract Effects of repeated applications of preemergence herbicides (alachlor, metolachlor, oxadiazon, and simazine) at 1 ×, 2 ×, and 4 × rates to leatherleaf fern [ Rumohra adiantiformis (Forst.) Ching] beds were studied. During the first two years of bed establishment, all herbicides reduced weed coverage compared to commercial practice (hand-weeding 3 times per year), but only simazine and oxadiazon suppressed weed coverage to commercially acceptable levels between hand-weedings. In year 3, when the fern beds had become well-established, all herbicide treatments provided adequate weed suppression. Simazine was phytotoxic to the fern and reduced yield. Metolachlor increased rhizome mortality compared to commercial practice. Herbicide and weed-free treatments had no effect compared to commercial practice on frond fresh and dry weights or postharvest water uptake and longevity of cut fronds. Chemical names used: 2-chloro- N -2,6-diethylphenyl)- N -(methoxymethyl)acetamide (alachlor); 2 chloro- N -(2-ethyl-6-methylphenyl)- N -(2-methoxy-1-methylethyl)acetamide (metolachlor); 3-[2,4-dichloro-5-(l-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2(3 H )-one (oxadiazon); 6-chloro- N, N ′-diethyl-1,3,5-triazine-2,4-diamine (simazine).