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Abstract

Ancymidol [α-cyclopropyl-α-(p-methoxyphenyl)-5-pyrimidinemethanol] applied as a bulb-dip prior to planting was more efficient (based on amount of active ingredient required) in controlling height of Easter lily (Lilium longiflorum Thunb. cv. Ace) height than soil drench or foliar spray applications. The method of application did not affect emergence or number of flowers, but flowering was delayed in plants receiving 0.5 and 1.0 mg a.i. as a bulb dip.

Open Access
Authors: and

Abstract

Ancymidol [α-cyclopropyl-α-(ρ-methoxyphenyl)-5-pyrimidinemethanol] applied at concentrations above 25 ppm active ingredient (a.i.) as a quick bulb-dip prior to cooling significantly reduced ‘Ace’ Easter lily height. Postcooling dips were not as effective and postemergence soil drenches were least effective. There was a trend toward delayed emergence and delayed flowering with increasing ancymidol concentrations when applied as bulb-dips either prior to or after cooling, however, significant delays occurred only with higher concentrations applied after cooling.

Open Access
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Abstract

Foliar sprays of undecanol increased branching in some cultivars of Euphorbia pulcherrima Willd. compared to unpinched controls, but did not increase branching compared to manually pinched plants. However, phytotoxicity at concentrations necessary to achieve these results made the plants marketably unacceptable.

Open Access
Authors: and

The State Botanical Garden of Georgia serves as an important academic resource for the University of Georgia by supporting interdisciplinary learning experiences in fields including botany, horticulture, environmental design, ecology, anthropology, geography, instructional technology, science education, entomology, forestry, and art. Field trips, independent study, internships, work-study and other botanical garden experiences strengthen and support the university's teaching, research and public service/outreach missions.

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Abstract

Ethyl hydrogen 1-propylphosphonate (EHPP) foliar sprays increased branching and reduced height of Ilex crenata Thunb. ‘Hetzi’ but not plant dry weight Phytotoxicity was extensive above 8,000 ppm EHPP, but acceptable at lower concentrations. Plant quality as determined by branching and phytotoxicity was optimal at 6,000 ppm EHPP. Time of application had no effect on height or dry weight, but when applied near the time of a terminal growth flush, EHPP increased branching. Phyto toxicity was severe if EHPP application was delayed several weeks after the growth flush had begun.

Open Access

Abstract

Ethyl hydrogen 1-propylphosphonate (EHPP) applied to Ilex crenata, Thunb. ‘Hetzi’ increased the number of branches. The optimum concentration for branching was 4000 ppm. Higher concentrations reduced branching, produced phytotoxicity, and delayed regrowth. Plant dry weight was inversely proportional to concentration at rates above 2000 ppm.

Open Access

Abstract

Hydrogel incorporated in the growing media of 2 bedding plants, marigold ‘Dolly’ (Tagetes erecta L.) and zinnia ‘Pink Buttons’ (Zinnia elegans Jacq.) grown in 3 different size containers generally increased hours to wilting (HTW) sequentially in both species and with increasing rates of hydrogel over the range tested (4 to 16 kg/m3). HTW of marigold and zinnia grown in 5.1 cm3 containers in hydrogel amended media at 16 kg/m3 increased 45 and 37%, respectively. High rates of hydrogel incorporation were as effective in increasing HTW in small containers as was doubling container size. Pressure bomb studies with plants grown under stress in hydrogel-amended media confirmed the reduction in internal moisture tension.

Open Access

Abstract

Weeping fig (Ficus benjamina L.) plants were greenhouse-grown under full sun or 75% light exclusion. Shade-grown leaves were larger, thinner, flatter, and darker green than sun-grown leaves. Sun- and shade-grown plants had the same total leaf area and were the same height. Shade-grown leaves had a single, poorly developed palisade layer with large chloroplasts dispersed throughout the palisade cells. Sun-grown leaves had one or two layers of well developed palisade cells with the chloroplasts aligned primarily along the radial walls. Stomatal density was greater in sun-grown leaves, but shade-grown leaves had more stomata per leaf.

Open Access

Abstract

Suitable conditions for determining net photosynthesis (Pn) of individual sun- and shade-grown leaves of weeping fig (Ficus benjamina L.) were 21°C dew point and an air flow rate between 1 and 3 liters/min. A diurnal trend in Pn occurred for sun leaves, with maximum rates between 0800 and 1200 hr; shade leaves did not decline in Pn until mid-afternoon. Leaves which originated from nodes 4 through 10 (from the shoot apex) did not differ in Pn, transpiration (Tr), specific leaf weight (SLW), or leaf water content. Shade-grown leaves had a photosynthetic advantage over sun-grown leaves at levels of photosynthetically active radiation (PAR) below 77 μE m−2s−1, whereas at PAR levels above 100 μE m−2s−1 the reverse was true. Sun-grown leaves had higher Tr rates than shade grown leaves at all PAR levels used.

Open Access

Abstract

Weeping Hg (Ficus benjamina L.) plants grown under 3 light regimes (full sun, full sun followed by 8 weeks acclimatization under 75% shade, and 75% shade) were placed in a low-light simulated interior environment (SIE) for 12 weeks. Acclimatized and shade-grown leaves had higher net photosynthesis (Pn) rates, lower dark respiration (Rd) rates, and lower light compensation points (LCP) than sun-grown leaves after 12 weeks in the SIE. No treatments increased total plant dry weight during the 12 weeks of SIE. However, percent dry matter of sun plants was redistributed with additional leaves produced at the expense of root carbohydrate reserves. Leaf production exceeded abscission in all treatments. Anatomical observations prior to and following the SIE indicated chloroplast reorientation in all treatments. The development of large, heavily stained chloroplasts suggest ultrastructural changes may also occur as a result of low light.

Open Access