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  • Author or Editor: Thomas A. Fretz x
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Abstract

Alachlor (2-chloro-2′,6′-diethyl-N-(methoxymethyl)-acetanilide), diphenamid (N,N- dimethyl-2,2-diphenylacetamide) and napropamide (2-(α-naphthoxy)-N,N-diethylpropionamide) provided excellent broadleaf and grass weed control. Alachlor significantly injured the ‘St. John's Fire’ Salvai while diphenamid caused moderate injury to ‘Golden Torch’ Celosia. Both trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) and DCPA (dimethyl tetra-chloroterephthalate) provided less than acceptable control of broadleaf weeds at the rates employed, but neither caused significant injury to any of the 15 cultivars of transplanted annual bedding plants used in this study.

Open Access
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Abstract

Dry wt of Japanese holly (Ilex crenata (Thunb.) cv. convexa Makino.) decreased significantly as the density of competing weed species increased. One redroot pigweed plant (Amaranthus retroflexus L.) reduced the dry wt of Japanese holly by 47% in 2.4 liter and 30% in 6.0 liter containers and 1 plant of large crabgrass (Digitaria sanguinales (L.) Scop.) caused reductions in dry wt of Japanese holly of 60% in 2.4 liter and 35% in 6.0 liter containers.

Open Access
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Abstract

Media temperatures surpassed 120°F in 1 gal nursery containers of both steel and high density polyethylene without plants when exposed to direct solar radiation. White, silver, and yellow exterior colors significantly reduced media temperatures when compared to darker colored metal containers. Surface barriers of black or clear polyethylene increased media surface temperatures significantly while aluminum foil and pressed white fiberglass disks had no effect on media temperatures in comparison to containers without surface barriers. In a 6 × 6 container to container configuration, those on the southern exposure exhibited significantly higher media temperatures than similar containers on the northern exposures or toward the center of the configuration. None of the artificial media examined significantly reduced temperatures in the containers.

Open Access

Abstract

The Ohio Cooperative Extension Service and The Ohio State University sponsored a symposium December 9-10, 1977 for members of the nursery production and scientific communities to update their knowledge and exchange ideas as it related to the winter storage of woody ornamentals. The symposium participants discussed the physiology of winter storage, pre-storage practices, determining maturity and prediction of harvest dates, acclimating plants to storage, principles of common and refrigerated storage, construction and orientation of storage structures, poly-coverings, disease control, anti-transpirants, minimum-heat, thermoblankets, heat saving techniques, and future needs. A summary of the discussions as well as research ideas are presented in this report. Copies of the proceedings of the Woody Ornamentals Winter Storage Symposium can be obtained for $5.00. Persons interested should enclose a check payable to Storage Symposium to Dr. Elton M. Smith, Department of Horticulture, 2001 Fyffe Court, Columbus, Oh, 43210.

Open Access

Abstract

Horticulture in the Commonwealth of Virginia has been greatly influenced by the topography of the state, and by the heritage of early settlers. In the Handbook of Virginia, published in 1866, 6 “great natural divisions” were recognized: the Tidewater, Middle Virginia, Piedmont, the Blue Ridge, the Shenandoah Valley, and Appalachia. These divisions, which rise in altitude from east to west, were said to have “differences of climate, soil production and require separate considerations in every respect.” Superimposed on these regions were the culture and national heritage of the settlers which had a great influence on the scope and scale of the state's agricultural development.

Open Access

Abstract

Pre-emergent applications of rodiamine-2% G [2,4-dinitro-N3,N3-dipropyl-6-(tri-fluoomethyl)-1,3-benzene-diamine] at 1.7, 3.4, 6.7 and 13.4 kg ai/ha effectively controlled large crabgrass (Digitarla sanguinalis (L.) Scop.), redroot pigweed (Amaranthus retroflexus L.), and common lambsquarter (Chenopodium album L.) for up to 113 days after application. No injury was noted on any of the test species following application of prodiamine when compared to the control plots.

Open Access

Abstract

Root penetration of Euonymus data (Thunb.) Siebold ‘Compactus’ through a peat-soil (1:1 v/v) medium and into an unamended mineral soil increased as medium density increased from 1.3 to 1.8 g/cm3. Root penetration was decreased at all medium densities across a glazed interior medium-soil interface.

Open Access

Abstract

Postemergent applications of bentazon (3-isopropyl-1H-2, 1-3-benzothiadiazon-(4) 3H-one 2, 2 dioxide) at 0.84, 1.68, 3.36 and 6.72 kg ai/ha effectively controlled yellow nutsedge (Cyperus esculentus L.) in nursery containers but all rates severely injured container-grown woody ornamentals.

Open Access

Abstract

Seeds of onion (Allium cepa L cv. Northern Oak) soaked in methyl sulfanilylcarbamate (asulam) showed mitotic irregularities in expanding root-tip cells including arrested metaphases and anaphase and chromosome bridges. Asulam at 2.4 μM increased the percentage of arrested metaphase figures after 31 hours.

Open Access