Search Results

You are looking at 1 - 10 of 11 items for

  • Author or Editor: R. Warner x
Clear All Modify Search
Authors: and

Hibiscus spp. seed were germinated and placed under different photoperiod treatments at 15, 20, or 25± 2°C. Photoperiod treatments were 9 hr, ambient daylight (≈9 hr) plus night interruption lighting (2200–0200 hr, 2 μmol·m–2·s–1 from incandescent lamps), or ambient daylight plus continuous light (100 μmol·m–2·s–1 light from high-pressure sodium lamps). Treatments were terminated at anthesis or after 20 weeks. Variation in flowering form and plant habit were documented and will be discussed. Temperature/photoperiod effects/interactions on plant development will be presented. Species were classified into appropriate photoperiodic groups. Those species with potential as new commercial floriculture crops will be presented.

Free access

Cotyledon explants and zygotic embryos of Lycopersicon esculentum H132, OH8442, and OH2253 were cultured on Murashige and Skoog medium containing varying concentrations of 2,4-D and NAA with and without 10-7 M zeatin. NAA above 10-5 M and 2,4-D above 10-6 M inhibited root formation from cotyledons. Zygotic embryos were removed from developing ovules at the globular, heart, and torpedo stages and later germinated on hormone-free medium. Globular structures that resembled immature zygotic embryos were produced at NAA concentrations between 10-4 and 10-3 M and 2,4-D concentrations between 10-5 and 10-4 M. Treatments reported to enhance maturation and germination of somatic embryos of other species, including subculture to a hormone-free medium with and without activated charcoal, the addition of an ABA treatment subsequent to the auxin treatment, isolation of individual structures from the explant, and a liquid medium rinse containing activated charcoal, have not been successful in stimulating further development of the globular structures.

Free access
Authors: , , and

Gomphrena globosa L. `Gnome Pink' and Salvia farinacea Benth. `Victoria Blue' were grown under different photoperiod treatments with day and night temperatures ranging from 15 to 30°C ± 1°C air temperature for 14 weeks after germination or until anthesis. Days to anthesis and leaf number were lowest when plants were grown under 9 hr of daylight and daylight plus 4-hr day extension from 1700–2100 HR (100 μmol·m–2·s–1 from high-pressure sodium lamps) for Gomphrena and Salvia, respectively. Days to anthesis decreased as temperature increased from 15 to 25°C with Gomphrena. Further increasing night temperature from 25 to 30°C delayed flowering and increased leaf number below the first flower of Gomphrena, but hastened flowering of Salvia. Plant height and internode elongation were greatest and least in the night interruption (2 μmol·m–2·s–1 from incandescent lamps from 2200–0200 HR) and continuous light (daylight plus 100 μmol·m–2·s–1 from high-pressure sodium lamps) treatments, respectively. Implications of these data with respect to classification of Gomphrena and Salvia flower induction are discussed and revised production schedules are presented.

Free access

Abstract

‘Giant Cavendish’ (‘Williams Hybrid’) banana (Musa acuminata Colla) was grown at the Waimanalo Research Station on Oahu, Honolulu, in 8 blocks with 48 mats per block. Nitrogen was applied as a continuous gradient across the width (6 mats) of each block. Potassium applications varied continuously over the length (8 mats) of the block. A 10 cm wide strip of leaf lamina was secured on a monthly schedule from each side of the midrib at the widest point of the 3rd fully unfurled leaf of (nonbearing) shoots which received the 4th level of N and the 5th level of K. Mats from which these samples were taken were designated as control mats, with the amount and frequency of fertilization applied sufficient to maintain them at about 2.6% N and 3.2% K. Other mats were fertilized on the same schedule as the control mats. Amounts of fertilizer applied were always in a fixed ratio, both greater than and less than the control mats. A leaf sample was secured from each shoot of each mat soon after the flower bud had emerged. The 3rd full-sized leaf below the inflorescence was sampled. Leaf N levels were associated with banana yield. Yields approached maximum at about 2.8% N. Amounts of N fertilizer required were increased greatly by a heavy infestation of Cyperus rotundus L. This weed decreased yields independently of its competitive effects for N. There were few indications of a K deficiency under the conditions of this trial, although heavy K fertilization was required to maintain leaf K at 3.2% in the control mats. The results of K fertilization suggest that surface application is not a very effective means of supplying K to banana plants. The general pattern of K uptake indicated that banana was utilizing K from the subsoil. Suspected incipient sulfur deficiency was not confirmed.

Open Access

Petunia × hybrida Vilm. cvs. `Purple Wave', `Celebrity Burgundy', `Fantasy Pink Morn', and `Dreams Red' were treated with temperature and photoperiod treatments for different lengths of time at different stages of development during the first 6 weeks after germination. Plants were grown with ambient light (≈8–9 hr) at 16°C before and after treatments. Flowering was earliest and leaf number below the first flower was lowest when plants were grown under daylight plus 100 μmol·m–2·s–1 continuous light (high-pressure sodium lamps). Flowering did not occur when plants were grown under short-day treatment (8-hr daylight). Plants grown with night interruption lighting from 2200–0200 HR (2 μmol·m–2·s–1 from incandescent lamps) flowered earlier, and with a reduced leaf number compared to plants grown with daylight + a 3-hr day extension from 1700–2000 HR (100 μmol·m–2·s–1 using high-pressure sodium lamps). Plant height and internode elongation were greatest and least in night interruption and continuous light treatments, respectively. `Fantasy Pink Morn' and `Purple Wave' were the earliest and latest cultivars to flower, respectively. Flowering was hastened as temperature increased from 12 to 20°C, but not as temperature was further increased from 20 to 24°C. Branching increased as temperature decreased from 24 to 12°C. Implications of data with respect to classification of petunia flower induction and pre-fi nishing seedlings are discussed.

Free access
Authors: , , , and

Viola × wittrockiana Gams. cvs `Delta Pure Rose' and `Sorbet Yellow Frost' were grown under different photoperiod and temperature treatments (12–24 ± 2°C) for different lengths of time at different stages of development during the first 6 weeks after germination. Plants were grown with ambient light (≈9 hr) at 16°C before and after treatments. Days to anthesis and leaf number were lowest when plants were grown under night interruption from 2200–0200 hr (2 μmol·m–2·s–1 from incandescent lamps) and daylight plus continuous light (100 μmol·m–2·s–1 from high-pressure sodium lamps) for `Sorbet Yellow Frost' and `Delta Pure Rose', respectively. Days to anthesis decreased as temperature increased from 12 to 24°C. Plant height and internode elongation were greatest and least in the night interruption and continuous light treatments, respectively. Branching decreased as temperature increased from 12 to 24°C. Implications of these data with respect to classification of Viola × wittrockiana flower induction and development of prefinished seedlings is discussed.

Free access

Abstract

Peroxidases from certain Musa spp. isolated using horizontal Polyacrylamide gel electrophoresis revealed 4 major zones of activity and 15 separate peroxidase bands. Good agreement was obtained among cultivars of different ploidy groups when composite zymograms were constructed from gel data and compared to a current taxonomic classification. Three clones of unknown origin were genotypically classified as ‘Hapai’ (AA); ‘Tuu Gia’ (AA); and ‘Eslesno’ (AAB).

Open Access

Variation in red/far red leaf and photosynthetically active radiation (PAR) absorption by an individual leaf of various ornamental hanging basket species was measured. Red/far red ratios varied from 0.30 to 0.83 for Syngonium podophyllum Schott. and Chlorophytum comosum Thunb. `vittatum', respectively. Reduction in PAR varied from 86% to 61% for those same species, respectively. Estimated state of phytochrome photoequilibria for understory crops when grown under each species was calculated. Cucumis sativus L. seedling hypocotyl elongation was measured under different species to validate hypothesized differences in stem elongation associated with differences in red/far red filtering through individual leaves. Implications with respect to light quality effects on stem elongation and dry weight accumulation of plants grown under different species are discussed.

Free access
Authors: , , and

Previous research indicated that Raphanus sativus L. `Chinese Radish Jumbo Scarlet' (CJRS) has an obligate vernalization requirement for flowering and can be vernalized as an imbibed seed in less than 10 days at 6 °C. For these reasons, it serves as an excellent model system for vernalization studies. This study was initiated to gain an understanding of the interaction between cold duration, exogenously applied GA3, and photoperiod on R. sativus CJRS flowering. R. sativus CJRS seeds were sown in 90-mm petri plates on Whatman no. 1 filter paper saturated with plain water or a solution containing 10-5 M or 10-3 M GA3. After germination (i.e., when the radicle was visible), seedlings were either directly transplanted into 10-cm pots and placed in a greenhouse, or transferred to another petri plate onto filter paper saturated with water only and placed in a growth chamber at 6 °C (75 μmol•m-2•s-1 for 8 h) for 2, 4, 6, 8, or 10 days. Greenhouse conditions were: 20 °C, ambient light (December to January, St. Paul, Minn.) plus 70 μmol•m-2•s-1 supplemental light (high-pressure sodium lamps, 0830-1630 hr), under either an 8-h photoperiod (covered with opaque cloth from 1630-0830 hr), or ambient photoperiod plus night-interruption lighting (2 μmol•m-2•s-1, using incandescent lamps, 2200-0200 HR). Results will be presented.

Free access

Nursery and greenhouse growers have an important role to play in conserving water resources. Many technologies are available to help growers conserve water. Yet, within the industry, there may be varying levels of knowledge about a specific strategy, along with inconsistent adoption and continued use. An understanding of these factors can be incorporated into educational programming for this audience. This study evaluated the reported knowledge level of U.S. greenhouse and nursery growers about eight specific water conservation technologies and then explored the rate at which growers had adopted and continued or discontinued their use. Technologies were ranked from high to low adoption rate, beginning with drip irrigation, rainwater capture, water reuse, and microirrigation, followed by soil moisture sensors, climate-based irrigation, subirrigation, and finally an irrigation audit. Overall, greater levels of knowledge corresponded to both greater adoption and continued use of a technology. Other factors, such as economic cost and technical feasibility are undoubtedly important. Findings highlight an opportunity to focus educational programs on the systems-based strategies that are beneficial to growers, but growers are least knowledgeable about to increase adoption of effective water conservation methods that currently have low levels of grower implementation.

Free access