Woody ornamentals

Several studies have clearly shown that uncontrolled herbaceous weed growth may utilize more of the fertilizer than slower-growing woody ornamentals and conifer trees. The net result is that fertilization without weed management often is detrimental to crop productivity and profitability (Morgan and McCormack, 1973 Braekke et al., 1986 Wheeler et al., 1987 Townsend, 1995b Roth and Newton, 1996). 

Simazine is widely used for preemergence control in field-grown nursery stock in North America. Selective use in container nurseries also has been demonstrated (Ahrens, 1972 Fretz, 1974 Wadsworth, 1975 Bing, 1983). It is less widely used in container-grown nursery production because of potential leaching (Elmore et al., 1976), but is especially effective when applied in the fall or winter to control winter annual weeds in containers. Simazine currently is registered in the United States for 50 species of woody ornamental nursery stock and Christmas trees. Tables 18.1 and 18.2 list selected species of conifers and deciduous ornamental plants, respectively, and their observed tolerance to simazine at rates of 2.2-3.3kg/ha. Information for these tables was obtained from personal observations and the literature, including those references by Ries et al. (1959) Ahrens (1961) Ticknor (1972) and Schubert et al. (1986). 

Bingham, S.W. (1968). Economic evaluation for weed control in field-lined woody ornamental nursery crops. Proc. Am. Society Hort. Sci., 92 704-712. 

Robinson, D.W. and J.C. Kelly (1989). Further information on the tolerance of woody ornamentals to simazine. Proc. Br. Weed Control... 

Uses pre-emergence, early post-emergence or soil-incorporated herbicide to control most annual grasses and many annual broadleaf weeds in beans, corn, cotton, milo, peanuts, peas, soybeans, sunflower, and certain woody ornamentals. 

Uses nonsystemic insecticide to control leaf-eating larvae and leaf miners in forestry, woody ornamentals and fruit trees. 

Crop Rotation—Pathogenic organisms nearly always can be carried over from one growing season to the next in the soil or in plant debris. Continual production of the same or closely related crops on the same piece of land leads to a disease buildup. Crop rotation reduces the buildup of pathogens, but seldom provides complete disease control. Obviously, crop rotation is not always possible, practical, or desirable. Perennial crops such as trees, woody ornamentals and turfgrass must remain in one location for many years. Some crops, such as com, cotton, or wheat, often are more practical to grow on the same land year after year despite the potential for a buildup of plant disease pathogens. 

Economic Potential of Growth Regulators for Floriculture and Woody Ornamentals... 

Uses Selective preemergence herbicide used to control some grasses and many broadleaved weeds in soybeans, cucurbits, asparagus, groundnuts, potatoes and established woody ornamentals. 

---