Browsing by Author "Gilliam, Charles Homer"

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    Growth of Japanese holly as affected by nitrogen and growth regulators
    Gilliam, Charles Homer (Virginia Polytechnic Institute and State University, 1976)
    The effects of 3 nitrogen levels and 2 growth regulators on growth of winter and summer propagated cuttings of Ilex crenata cv. Helleri were studied. Nitrogen applications promoted bud break after rooting of summer cuttings and also enhanced the growth of winter rooted cuttings. Generally, plants grown at 300 and 150 ppm N had greater initial shoot numbers and length, secondary shoot numbers and length, height, width, fresh weight, and dry weight compared to plants grown at 50 ppm N. Initially, benzyladenine (BA) at 600 ppm decreased the number of primary breaks and decreased the stem length, while gibberellic acid (GA) at 400 ppm decreased the number of primary bud breaks and increased stem length. The hormone responses persisted for approx. a month, starting a fortnight from the first application. GA₃ + BA caused very erratic responses. There were no N-growth regulator interactions.
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    Some aspects of nitrogen nutrition on selected Ilex
    Gilliam, Charles Homer (Virginia Tech, 1977-09-05)
    Three holly cultivars, Ilex crenata, Thunb. 'Helleri' and 'Rotundifolia' and Ilex cornuta Lindl. et Paxt. 'Burfordi' were grown in 3 liter containers at 200, 300, 400 and 500 ppm nitrogen (N). Significant correlation coefficients were found between plant growth (dry wt accumulation) and both leaf N content and soil solution nitrates, while low correlation coefficients were found between soil nitrates and plant growth. Shoot growth of 'Helleri' and 'Burfordi' was not increased by N levels higher than 300 ppm while 400 ppm N was optimal for 'Rotundifolia'. The effects of 3N levels on tissue N fluctuations during a flush of growth on 'Helleri' were also studied. For all N levels, tissue N levels were shown to increase following the cessation of stem elongation until a level of tissue N was reached where a new flush of growth began. These N levels were approx the same for all N treatments. The time necessary to reach this level 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 levels began to decrease. The response of 'Helleri' to 15 fertilizer treatments consisting of different time and lengths was studied. Fertilizer applied during a period following the cessation of stem elongation and before the next flush resulted in greater total N and shoot growth, regardless of whether it was also applied during other weeks or not. Root growth was suppressed by 3 or more fertilizer applications, regardless of the time of application.