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Abstract
The effects of 3 nitrogen levels and 2 growth regulators on growth of winter- and summer-rooted cuttings of Ilex crenata cv. Helleri were studied. Nitrogen applications promoted bud break immediately after rooting on summer cuttings and also enhanced the growth of winter-rooted cuttings. Generally, plants grown at 300 or 150 ppm N had greater shoot numbers and length, height, width, and dry weight compared to plants grown at 50 ppm N. Also spring growth of these liners was markedly enhanced by the higher level of N applied the previous season. Benzyladenine (BA) at 600 ppm increased the number of breaks and suppressed stem length, while gibberellic acid (GA3) at 400 ppm decreased the number of breaks and increased stem length.
Abstract
Taxus media Rehd. ‘Anderson’ were grown at 4 boron rates: 0.5, 5.0, 25.0 and 50.0 ppm using 2 media:4 pinebark:l sand and 4 hardwood bark:l sand. toxicity symptoms developed when foliar concentration was between 85–100 μg/g of dry tissue. Foliar symptoms of toxicity were characterized by leaf-tip yellowing followed by leaf-tip necrosis and premature defoliation. Shoot and root growth were suppressed at the 50 ppm application rate. continued to accumulate in the foliage after the 2 higher rates of were discontinued. Foliar concentration of Ca, Mn, Fe and Zn were lower when plants were grown with 25 and 50 ppm when compared to plants grown with 0.5 and 5 ppm B.
Abstract
Fertilizer applied during a period following the cessation of stem elongation and before the next flush resulted in greater total tissue N and shoot growth than applications made during other stages of growth in ‘Helleri’ holly. Root growth was suppressed by 3 or more fertilizer applications, regardless of the time of application.
Abstract
The effects of 3 nitrogen treatments on tissue N fluctuations of ‘Helleri’ holly. All N concentrations increased following the cessation of shoot elongation until a concentration of tissue N was reached where a new flush of growth began. Nitrogen concentrations at which new growth began were about the same for all N treatments. The time necessary to reach this concentration was dependent on the level of N added; 5 weeks for 300 ppm, 13 weeks for 150 ppm and 18 weeks for 50 ppm N. Once new growth began, tissue N concentrations began to decrease.
Abstract
High correlation coefficients were found between plant growth (dry weight accumulation) and both leaf N content and soil solution nitrates, while low correlation coefficients were found between soil nitrates and plant growth of 3 holly cultivars, Ilex crenata Thunb. cvs. Helleri and Rotundifolia and Ilex cornuta Lindl. et Paxt. cv. Burfordi, grown in 3 liter container at 200, 300, 400 and 500 ppm nitrogen. Shoot growth of ‘Helleri’ and ‘Burfordi’ was not increased by N levels higher than 300 ppm, while 400 ppm was optimal for ‘Rotundifolia.’
Abstract
Selected herbicides were evaluated for control of southern yellow wood sorrel (Oxalis dillenii Jacq.) in three experiments. Control varied depending on rate of application and the time interval after application. Herbicides providing excellent control (less than one weed/pot) 8 weeks after treatment with the 0.5 × rate included: oxyfluorfen, 1.1 kg·ha–1; oryzalin, 2.2 kg·ha–1; and oxyfluorfen + oryzalin, 1.7 kg·ha–1. Control 18 weeks after treatment was excellent at the 1× rate with oryzalin (4.5 kg·ha–1) and at the 2× rates with oryzalin (9.0 kg·ha–1), oxyfluorfen (4.5 kg·ha–1), and a combination of the two. Chemical names used: 2-chloro-l-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene (oxyfluorfen); 4-(dipropylamino)-3,5-dinitrobenzenesulfonamide (oryzalin).
Improved water use efficiency exists for plants grown in modified containers to minimize leaching and reduce irrigation frequency which subsequently reduces NO3-N leachate. Salvia splendens `Bonfire' and Impatiens wallerana `Pink' (super elfin hybrid) were potted in ProMix BX medium (Premier Brands, Inc., Stamford, CT) into nine container styles with modified drainage holes to determine leachate volume and quantify NO3-N leached. Three styles had four drainage holes on the container side with hole diameters of 0.5, 1.0, and 1.9 cm, respectively; three styles had four drainage holes on the container side and one drainage hole in the bottom center with hole diameters of 0.5, 1.0, and 1.9 cm, respectively; and three styles had one drainage hole in the bottom center with hole diameters of 0.5, 1.6, and 1.9 cm, respectively. Plants were hand watered when an individual container's medium reached 80% of container capacity. Leachate volume, irrigation frequency, and leachate NO3-N was reduced as drainage size hole decreased in size and number. Plant quality was similar among container modifications.
Abstract
Phytotoxicity associated with application of 0.28 kg·ha−1 a.i. of the 4E formulation of fluazifop-butyl to Rhododendron ‘Hino-crimson’ was characterized by plant response similar to the response to chemical pinching. Flowering the following spring increased with fluazifop-butyl treatment. In a separate study, application of 1E PP005 (a formulation containing only the active isomer fluazifop-butyl) produced effects similar to the 4E formulation at one-half the rate (0.14 kg·ha−1). Chemical name used: butyl (±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoic acid (fluazifop-butyl).
Abstract
Boston fern [Nephrolepis exaltata (L.) Schott ‘Rooseveltii’] was grown with sufficient and insufficient levels of N and K and leaf nutrient concentrations were determined periodically from 4 frond sections: frond tips, 10–12 cm; frond midsections, 10–12 cm; frond bases, 10–12 cm; and whole fronds, 30–40 cm. Both the frond midsection and the whole frond were found to be acceptable for foliar analysis. Frond tips had the lowest nutrient concentrations for most elements. Foliar N was similar for all frond sections sampled. Nitrogen deficiency symptoms occurred after 2 to 4 weeks of minus N conditions. When three N sources were added to plants grown under minus N conditions, N source had a limited influence on N uptake as measured by foliar analysis. One and 2 weeks after N treatment was restored to N-deficient ferns, foliar N had increased 55 and 100%, respectively.
Abstract
In field production of nursery stock, plant losses may occur after digging but before plants leave the nursery, thereby reducing profitability. Although little information is available, it appears this plant loss may result from moisture stress induced by root pruning at digging and subsequent handling procedures (2, 3). To ensure adequate roots in the rootball, most nurserymen dig root-balls in accordance with the American Standard for Nursery Stock (ASNS) (1), which allows for increasing rootball size with increased shoot growth.