Search Results
Abstract
Inflorescence development and fruit set of ‘Burford’ holly was rapid at a day/night temperature of 26°/22°C and progressively slower at 22°/18° and 18°/14°. The number of flowers to set fruit, however, was increased at lower temperatures for both long photoperiod (LD = 9 hours + 3 hours dark interruption) and short photoperiod (SD = 9 hours). At 22°/18°, SD increased fruit set over LD. No significant temperature-photoperiod interaction was observed. A greater number of vegetative shoots developed as temperature increased and mean shoot length was correlated with the number of flowers to set fruit.
Abstract
Foliar application of 6-benzylaminopurine (BA) to Ilex crenata cvs. Helleri and Rotundifolia increased the number of axillary shoots per plant. ‘Helleri’ axillary shoot number was increased 4 times by 500 ppm BA whereas axillary shoot number of Rotundifolia was increased 1.5 and 3 times by 100 and 500 ppm respectively. Leaf size and shoot length were significantly reduced by 500 ppm BA.
Abstract
‘Burfordii’ holly was grown at day/night temperature combinations of 26°/22°, 22°/18° and 18°/14°C under either a long photoperiod (LD = 9 hours + 3 hours dark interruption) or short photoperiod (SD = 9 hours). The number and growth of new shoots were significantly greater at 26°/22° than at 22°/18° and no shoot growth occurred at 18°/14°. Leaf size was significantly smaller at 26°/22° than at 22°/18°. Holly shoot growth was greater under LD than SD. No significant temperature-photoperiod interaction was observed.
Abstract
Ilex cornuta ‘Burfordii’ holly plants were maintained at 3-4°C for 0, 2, 4, 6 or 8 weeks. Following these treatments, the number of flowers to develop were greatest on plants receiving 6 or 8 weeks of chilling. Time required for flowering to begin and the duration of flowering was shortened by the longer exposures to cold treatment
Abstract
Intemodal and stem lengths of new growth and plant diameter of dwarf Japanese holly (Ilex crenata Thunb. cv. Helleri) were significantly increased by sprays of 100, 200, or 400 ppm gibberellin A4+7 (GA4+7). GA3 was less effective than GA4+7, but also significantly increased stem length and plant diameter. Leaf size was decreased by GA3 and GA4+7 applications.
Abstract
Greenhouse-grown branched liners of ‘Helleri’ holly were fertilized with either 0, 5, 10, 15, 20, 25, or 30 ppm P to establish a P level in the pine bark medium that resulted in maximum shoot dry weight. Pine bark P levels greater than 10 ppm did not result in increased shoot dry weight. Total mg of P in shoot tissues continued to increase with P treatments higher than 10 ppm, indicating luxury consumption of P. Total mg of P in root tissues increased to the 5 ppm P treatment. Total μg of Mn in shoot tissues increased while total pg of Mn in root tissues decreased with increasing pine bark P levels. In a subsequent experiment, dry shoot weights of ‘Helleri’ holly grown in a pine bark medium amended with either 270, 540, or 810 g/m3 of P supplied as superphosphate (9% P) or fertilized with 10 ppm P were not different, while root dry weights decreased with increasing P amendment. Water extractable P for the 810 g/m3 treatment decreased 245 ppm during the experiment and by week 5 was below 10 ppm.
Abstract
Determinations of carbohydrates in the plant organs of Rhododendron spp. cv. ‘Sweetheart Supreme’ and ‘Hexe’, were made by chemical analysis, thin-layer chromatography (TLC) and gas-liquid chromatography (GLC). Reducing sugar content was 1.5 times higher in buds than in leaves for ‘Hexe’ with no significant differences for ‘Sweetheart Supreme’. Reducing sugars were also higher in the roots than stems with both cultivars. Sucrose content was 1.4 times greater in leaves than in buds of ‘Hexe’ and 1.6 times greater in ‘Sweetheart Supreme’. Starch was significantly higher in leaves and buds than in stems and roots. The predominant soluble sugars identified by TLC and GLC were sucrose, glucose, and fructose. Small but detectable amounts of raffinose and maltose and an unidentified compound were also found in the plant organs.
Abstract
Higher N rates applied to Ilex crenata‘ Helleri’ holly liners grown in the greenhouse increased shoot growth but-decreased root growth resulting in a greater shoot:root ratio. Higher N rates reduced the time required for a shoot growth flush to occur. Ρ at 85-500 ppm had no effect on shoot or root growth. Continued growth of liners at 50 ppm N lowered the shoot:root ratio due to stimulation of root growth while 300 ppm N caused the shoot:root ratio to increase due to increased shoot growth.
Abstract
Ilex crenata ‘Helleri’ liners were greenhouse grown in sand culture and subjected to N rates which ranged from 14 to 108 ppm in one experiment and from 70 to 250 ppm in a second experiment. Maximum shoot dry weights occurred at 87 ppm N in the first experiment and at 100 ppm N in the second experiment. The number of plants per treatment initiating visible shoot elongation 17 days after the initiation of the fertilizer treatments was influenced by N treatment and 79% of the differences in final dry weights could be attributed to the time of visible shoot elongation initiation. The maintenance of 87–100 ppm N in the substrate nutrient solution, the range at which no further increase in shoot dry weight occurred, would maximize plant growth and most effectively utilize the applied fertilizer.