Search Results

You are looking at 1 - 6 of 6 items for :

  • Author or Editor: Janet C. Henderson x
  • HortScience x
Clear All Modify Search

Pyracantha coccinea `Lalandei' and `Kasan' were treated with a foliar application of 25, 50 or 100 mg/l uniconazole, 3000 mg/l chlormequat, a soil drench of 0.25, 0.50 or 1.00 mg/container of uniconazole, or 30 mg/container chlormequat. Heights of plants receiving foliar applications of uniconazole were significantly lower than untreated plants in both cultivars. Uniconazole soil drenches also reduced plant height in both cultivars, but differences were not apparent until 8 weeks after treatment. Chlormequat treatments had little effect on plant growth. At harvest, stem dry weight was significantly lower in both cultivars with uniconazole soil drenches and in `Lalandei' treated with 50 and 100 mg/1 and in `Kasan' treated with 100 mg/1 as a foliar application. There was also a tendency for leaf area to increase with uniconazole foliar applications.

Free access

Uniform liners of pyracantha (Pyracantha coccinea Roem `Lalandei'), photinia (Photinia × fraseri Dress) and dwarf Burford holly (Ilex cornuta Lindl. and Paxt. `Burfordii Nana') were potted into 3.8 liter containers in a pine bark:sand medium. Ten weeks later, plants received uniconazole treatments as a media drench or foliar spray. The uniconazole drench rates were 0, 0.5, 1.0, and 3.0 mg ai per container for all three plant species. The foliar application rates were 0, 50, 100 and 150 ppm for pyracantha, 0, 25, 50 and 100 ppm for photinia, and 0, 10, 25, and 50 ppm for dwarf Burford belly. Plant heights and widths were recorded at 3 week intervals, and leaf chlorophyll content was determined by calorimeter at the same time as height and weight measurements. At harvest, leaf counts, leaf areas, and shoot, leaf and root dry weights were determined. Initial results indicate that both foliar and media drench treatments of uniconazole reduced growth of pyracantha and photinia at all rates. Only the two highest rates decreased growth of dwarf Burford holly when applied as either a media drench or a foliar spray.

Free access

Pyracantha coccinea M.J. Roem. `Kasan' and `Lalandei' were treated with a soil drench of 30 mg a.i. chlormequat chloride per container or 0, 0.25, 0.50, or 1.00 mg a.i. uniconazole per container or with a foliar application of 3000 mg a.i. chlormequat chloride/liter or 0, 25, 50, or 100 mg a.i. uniconazole/liter. Chlormequat chloride applied as a drench did not affect growth of `Kasan' or `Lalandei' until 17 weeks after application, when `Kasan' was taller and `Lalandei' shorter than untreated plants. `Kasan' plants drenched with chlormequat chloride had more leaves with greater total leaf area and higher leaf and stem dry weights than untreated plants. However, area per leaf, root dry weight, and root: shoot ratio were not affected by the chlormequat chloride drench. In `Lalandei', the chlormequat chloride drench did not affect any of these criteria, except stem dry weight. Foliar applications of chlormequat chloride had little effect on either cultivar. Height of `Kasan' and `Lalandei' decreased with increasing uniconazole rates for both application methods. Area per leaf increased in `Kasan' but decreased in `Lalandei' receiving a drench applied to the medium. Foliar and drench applications of uniconazole both resulted in decreased stem dry weight of both cultivars. Chemical names used: 2-chloro-N,N,N-trimethylethanaminium chloride (chlormequat chloride); (E)-1-(p-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol (uniconazole).

Free access

Abstract

Studies were conducted to determine if ammonium or nitrate were retained by a starch-polyacrylamide hydrophilic gel. Silicia sand was amended with 0, 2, 3, and 4 kg/m3 hydrophilic gel. Ammonium nitrate solution was applied to dry and distilled water-saturated amended sand in pots. The amended medium was washed with distilled water, leachate was collected, and ammonium and nitrate contents were determined. More ammonium was retained by all concentrations of hydrophilic gel-amended sand than in sand alone, especially in media not saturated prior to application. Nitrate was not retained in large amounts by any medium.

Open Access

Abstract

Seeds of black locust (Robinia pseudoacacia L.), common honeylocust (Gleditsia triacanthos L.), and Kentucky coffeetree (Gymnocladus dioica L.) were coated with an adhesive plus hydrophilic gel, adhesive only, or neither (control), planted in sand in the greenhouse, and then irrigated at 3-, 6-, or 9-day intervals. Percent germination of black locust seeds irrigated at 3-day intervals was decreased significantly with exposure to hydrophilic gel. Gel-coated Kentucky coffeetree seeds irrigated at 6-day intervals also had a percent germination significantly lower than those treated with adhesive alone, but germination of untreated seeds was not different from adhesive- or gel-coated seeds. No other significant difference in germination percentage was observed. Seedling heights and dry weights were not affected by seed treatment; however, decreased moisture availability because of longer time periods between irrigations tended to delay emergence and reduced seedling vigor.

Open Access

Abstract

Studies were conducted to determine the effect of a hydrophilic gel used as a medium amendment or root dip on plant response to moisture deficits. Tomato (Lycopersicon esculentum Mill.) seedling roots were dipped in water or hydrophilic gel solution (7.4 g·liter−1) and planted in sand or a 1 sand : 1 very fine sandy loam mixture (v/v). Seedlings were also planted in the same medium amended with 3 kg·m−3 hydrophilic gel. Leaf water potentials and stomatal resistances were determined at various times after a final irrigation. Significantly greater leaf water potentials occurred in new transplants in sand amended with gel than in control or root-dipped plants. No effect on either leaf water potential or stomatal resistance was apparent for any treatment in finer textured soils. There were no treatment effects on plants exposed to the same gel treatment and allowed to establish for 2 weeks prior to withholding water.

Open Access