Herbicides for Container Grown Nursery Stock

Abstract

Over a 3-yr period 10 herbicides were tested alone or in combination for control of weeds and for effects on growth of nursery stock in containers. Annual bluegrass (Poa annuaL.) was controlled by norea [3-(hexahydro-4,7-methanoindan-5-yl)-1,1-dimethylurea], alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide], and combinations of diphenamid (N,N-dimethyl-2,2-diphenylacetamid), trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), and nitralin [4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline] plus simazine [2-chloro-4,6-bis(ethylamino)-s-triazine]. Bittercress (Cardamine oligospermaNutt.) was controlled by simazine, oxadiazon [2-tert-butyl-4-(2,4-dichloro-5-isopropoxyphenyl)-Δ2-1,3,4-oxadiazolin-5-one], and norflurazon [4-chloro-5-(methylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone]. Mouseear chickweed (Cerastium vulgatumL.) was controlled by dichlobenil (2,6-dichlorobenzonitrile) and norflurazon, and common groundsel (Senecio vulgarisL.) was controlled by dichlobenil and norflurazon. Some of the treatments decreased growth of certain nursery cultivars.

Herbicide Systems for Nursery Plantings

“…Combinations with oryzalin and simazine did not improve total weed control over either herbicide applied alone. Several researchers have reported similar results when mixing herbicides with simazine (7,8).…”

“…Tank mixtures of 2 herbicides often result in a greater spectrum of weed control (7,8) over the application of a single herbicide. Although the use of herbicide mixtures in nurseries can be advantageous to production costs, crop tolerance is a major concern to nurserymen and must be known prior to mak ing weed control recommendations.…”

Herbicide Treatment of Container-grown ‘Gloria’ Azaleas and ‘Merritt Supreme’ Hydrangeas

“…The use of herbicides to control weeds in container-grown ornamental plants has been under investigation for many years (19). Most studies on container-grown azaleas and hydrangeas have focused on treatment of nursery stock cultivars (18,23) during vegetative growth periods (1, 3,4,6,7,11,13,14,16,17,21).…”