scholarly journals 631 Interaction of Genotype and Temperature on the Floral Initiation of Pelargonium ×domesticum

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 556C-556
Author(s):  
Laurel L. Anderson ◽  
Laura M. Wakefield
Keyword(s):  
Mass Production ◽  
Flowering Plants ◽  
Control Group ◽  
Floral Initiation ◽  
Optimum Temperature ◽  
Rooted Cuttings ◽  
Potted Plant ◽  
Temperature Requirements ◽  
Growth Chambers ◽  
Culture Virus

Pelargonium ×domesticum has great potential as a flowering potted plant. Low-temperature requirements for floral initiation create an obstacle for mass production, and precise temperature requirements for floral initiation vary among cultivars. Our objective was to determine optimum temperature for floral initiation of six cultivars: Dandy, Debutante, Empress, Enchantment, Imperial, and Rapture. Four complete experiments were conducted at 1-month intervals beginning Oct. 1998. In each experiment, 120 culture-virus-indexed rooted cuttings were obtained commercially and planted into 15-cm plastic pots. After 1 week, terminals were removed and plants were allowed to grow for an additional 3 weeks. Plants then were subjected to three floral initiation treatments at 12, 15, and 18° C for 4 weeks under 16-h photoperiods in growth chambers. A control group was initiated in the greenhouse. Following initiation treatments, all plants were finished under standard greenhouse conditions, supplemented with HID light. On flowering, plants were evaluated for time to anthesis, number and size of inflorescences, and overall plant quality. The 15° C treatment consistently produced the highest quality plants, while the 12° C treatment scored lowest with regard to flowering and overall quality. Differences among the cultivars were observed for time to anthesis. `Imperial' and `Rapture' flowered earliest, followed by `Enchantment' and `Empress', with `Dandy' and `Debutante' requiring the most time.

scholarly journals Controlling Poinsettia (Euphorbia pulcherrima Will.) Height with Growth Retardant Application in West Java, Indonesia

2016 ◽  
Vol 3 (3) ◽  
pp. 89-92
Author(s):  
Dewi Sukma ◽  
Gina Megawati
Keyword(s):  
Plant Height ◽  
Growth And Development ◽  
Leaf Size ◽  
Flowering Plants ◽  
Growth Retardant ◽  
Euphorbia Pulcherrima ◽  
West Java ◽  
Internodal Length ◽  
Potted Plant ◽  
Plant Shoots

A study was conducted to evaluate the effects of the growth retardant Cycocel application in the growth and development of poinsettia (Euphorbia pulcherrima) ‘Freedom Red’.  Cycocel was applied by spraying plant shoots at the concentrations of 1000, 1500, 2000, 2500 ppm. The increase in cycocel concentrations reduced plant height, leaf size, internodal length, plant spread and the number of flowering plants. All cycocel concentrations resulted in an ideal potted plant height. The optimum spray concentration of Cycocel used to obtain compact and uniformly flowering plants under tropical West Java environment was 1000 ppm.

scholarly journals Effects of season, altitude and daylength on floral initiation of two contrasting genotypes of Trifolium repens L.

1986 ◽  
Vol 106 (1) ◽  
pp. 149-154 ◽  
Author(s):  
F. Von Sury ◽  
J. Nösberger
Keyword(s):  
Low Temperature ◽  
Seed Production ◽  
Floral Initiation ◽  
Cool Season ◽  
Production Potential ◽  
Low Latitude ◽  
Specific Effects ◽  
Trifolium Repens L ◽  
Growth Chambers ◽  
Main Factors

SUMMARYThe effects of season and altitude on floral initiation of two Trifolium repena L. cultivars, Haifa and California Ladino, were tested in the area of Ayacucho, Peru (2730 m, 13° S), with regard to their seed production potential. Specific effects of daylength at a constant temperature (20 °C) were examined in growth chambers.In Ayacucho, the proportion of inflorescence-bearing nodes was found to be lowest between December and June (Haifa 10–20%, Ladino 0–10%) and highest in August (Haifa 30%) and September–October (Ladino 15%). Late in the cool season, floral initiation of Ladino, but not that of Haifa, increased strongly at a high altitude (3250 m). In growth chambers, Haifa initiated few inflorescences and Ladino none in a 10 h daylength. In 16 h, the floral initiation of Haifa was very limited but Ladino formed many inflorescences. Floral initiation of Haifa was most pronounced and lasted longest after a daylength shift from 10 to 13 h.It is concluded that seasonal and altitudinal variations in low temperature were the main factors influencing floral initiation in the region of Ayacucho. Haifa is considered to be an intermediate-day plant, suited for seed production in the region because of its marked and early flowering. Ladino was classified as a quantitative longday plant, unsuitable for seed production at this low latitude because of its retarded floral response to low temperature.

scholarly journals The Effect of Daily Light Integral on Floral Initiation of Pelargonium ×domesticum L.H. Bailey

HortScience ◽  
2004 ◽  
Vol 39 (3) ◽  
pp. 529-532
Author(s):  
Marietta M. Loehrlein ◽  
Richard Craig
Keyword(s):  
Morphological Changes ◽  
Genotypic Variation ◽  
Floral Initiation ◽  
Daily Light Integral ◽  
Growth Chambers ◽  
Light Integral ◽  
Chronological Time

Nine cultivars of Pelargonium ×domesticum L.H. Bailey were evaluated for the effect of daily light integral on floral initiation. Plants were grown at four daily light integrals: 5, 10, 15, or 20 mol·m-2·d-1 for a 16-hour photoperiod in environmental growth chambers at constant 15.5 °C. Meristems were examined at 50 mol·m-2 intervals for morphological changes associated with floral initiation. Two phenotypes were identified, cultivars with an association between floral initiation and cumulative irradiance and those with association between floral initiation and chronological time. Genotypic variation was observed among the irradiance-associated phenotypes.

scholarly journals Effects of total replacement of dietary fish oil by vegetable oils on growth performance, nutritional quality and fatty acid profiles of rainbow trout (Oncorhynchus mykiss) at optimum and high temperature conditions

2021 ◽  
Vol 38 (2) ◽  
pp. 237-246
Author(s):  
Seval Dernekbaşı ◽  
Ayşe Parlak Akyüz ◽  
İsmihan Karayücel
Keyword(s):  
Rainbow Trout ◽  
Fish Oil ◽  
Growth Performance ◽  
Vegetable Oils ◽  
Nutritional Quality ◽  
Control Group ◽  
Optimum Temperature ◽  
Temperature Conditions ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Dietary Fish

The present study investigated the effects of total replacement of dietary fish oil by different vegetable oils on growth performance, nutritional quality and fatty acid profiles of rainbow trout (Oncorhynchus mykiss) at optimum and high temperature conditions. Five iso-nitrogenous and iso-lipidic diets including 100% fish oil and vegetable oils were prepared for rainbow trout fingerlings with an average weight of 11.27±0.01 g. After the fish were fed experimental diets for 9 weeks at the optimum temperature (17.74±0.01°C), all groups were fed an FO diet containing only fish oil for 4-weeks at the upper optimum temperature conditions (19.28±0.11°C). In both feeding trials, experimental fish were hand-fed ad libitium twice a day. Results showed that growth performance and feeding efficiency were significantly better (p<0.05) in groups fed by VO-based diets compared to groups fed by FO based diet at optimum temperature. Survival was 100% in CANO, SFO, CO PNO groups and 94.12±3.39% in FO (control) group at the end of the 9 weeks. Growth, feed consumption and survival of fish fed the upper-optimum temperature were significantly differed (p<0.05). In particular, while the survival rate of the groups fed with vegetable oil-based diets at optimum temperature and then fed only fish oil remained 100%, this rate decreased to 54.17±1.39% in the control group. Eicosapentaenoic acid (EPA, 20:5n-3), docosahexaenoic acid (DHA, 22:6n-3) and n-3 PUFA of fish fed by VO based diets were low. When all groups were fed only FO diet for 4 weeks at upper-optimum temperatures, EPA, DHA and n-3 PUFA ratios increased. In addition, after the upper-optimum temperature trial, increases in the nutritional quality indices of fish meat were also detected.

scholarly journals Lecanicillium spp. for the Management of Aphids, Whiteflies, Thrips, Scales and Mealy Bugs: Review

2020 ◽  
Author(s):  
Sajjalavarahalli Gangireddy Eswara Reddy
Keyword(s):  
Mass Production ◽  
Insect Pests ◽  
Control Agent ◽  
Natural Occurrence ◽  
Optimum Temperature ◽  
Development Of Resistance ◽  
Factors Influencing ◽  
Production Safety ◽  
Future Work ◽  
Chemical Pesticides

Lecanicillium spp. are potential microbial bio-control agent mainly used for the management of sucking insect pests such as aphids, whiteflies, scales, mealy bugs etc. and gaining much importance at present for management of pests. Due to indiscriminate use of chemical pesticides which results in development of resistance, resurgence, outbreak of pests and residue problem, the farmers/growers are forced to use bio-pesticides for sustainable agriculture. Lecanicillium spp. is promising biocontrol agent against sucking insect pests and can be used as one of the components in integrated pest management (IPM). However, optimum temperature and relative humidity are the major environmental factors, for the performance of Lecanicillium spp. under protected/field conditions. The present review is mainly focused on nomenclature of Lecanicillium spp., mode of infection, natural occurrence, influence of temperature and humidity on the growth, factors influencing the efficacy, virulence/pathogenicity to target pests, substrates used for mass production, safety to non-target organisms, compatibility with agrochemicals and commercially available products. This review is mainly useful for the researchers/students to plan their future work on Lecanicillium spp.

Deep complex morphophysiological dormancy in seeds of Viburnum plicatum var. formosanum (Adoxaceae) from subtropical mountains

2021 ◽  
pp. 1-7
Author(s):  
Shun-Ying Chen ◽  
Chiung-Pin Liu ◽  
Carol C. Baskin ◽  
Ching-Te Chien
Keyword(s):  
Warm Season ◽  
Evolutionary Relationships ◽  
Cold Stratification ◽  
Dormancy Release ◽  
Optimum Temperature ◽  
Cool Season ◽  
Morphophysiological Dormancy ◽  
Temperature Requirements ◽  
High Elevations ◽  
Shoot Emergence

Abstract Viburnum is a temperate-zone genus that also occurs in mountains of South America and Malesia, and seeds of many species have morphophysiological dormancy (MPD). Information on the level of MPD in seeds of species in various clades of Viburnum potentially would increase our understanding of the evolutionary relationships between the nine levels of MPD. Our aim was to determine the level of MPD in seeds of Viburnum plicatum var. formosanum that is endemic to mountains (1800–3000 m a.s.l.) in Taiwan and a member of the Lutescentia clade. The temperature requirements for embryo growth and root and shoot emergence and response of seeds to gibberellic acid (GA) were determined. No fresh seeds germinated during 16 weeks of incubation at 15/5, 20/10, 25/15, 30/20 or 25°C. Embryo growth and root emergence occurred during moist cold stratification at 5°C or at a temperature sequence of 15/5 to 5°C. During cold stratification, embryos length increased from 0.76 ± 0.06 to 3.40 ± 0.26 mm and the embryo length:seed length ratio from 0.20 ± 0.02 to 0.68 ± 0.07. In a temperature sequence simulating field conditions, embryos grew inside seeds at 5°C, roots emerged at 15/5°C and shoots emerged at 20/10°C. The optimum temperature for embryo growth was 5°C. Neither GA3 nor GA4 was effective in promoting root emergence. We conclude that seeds of V. plicatum var. formosanum have deep complex MPD, which is a first report for Viburnum. Dormancy release during the cool season at high elevations helps to ensure that seeds germinate at the beginning of the warm season.

Conditions for pycnidial production and spore formation by Ampelomyces quisqualis

1990 ◽  
Vol 36 (3) ◽  
pp. 193-198 ◽  
Author(s):  
Abraham Sztejnberg ◽  
Sergio Galper ◽  
Norberto Lisker
Keyword(s):  
Biological Control ◽  
Mass Production ◽  
Agar Medium ◽  
Great Increase ◽  
Spore Production ◽  
Spore Formation ◽  
Spore Concentration ◽  
Optimum Temperature ◽  
Potato Dextrose Broth ◽  
Ampelomyces Quisqualis

On Czapek agar medium, the optimum temperature for spore germination and pycnidia formation by Ampelomyces quisqualis was 20 and 25 °C, respectively. Inoculation of Czapek agar medium with a spore concentration of 106 or 107/mL significantly increased pycnidia formation as compared with medium inoculated with 104 or 105 spores/mL. In shaken cultures, spore formation in potato dextrose broth (PDB) was higher than in the broth of bran extract and glycerol, aspargine, Czapek, Joham, and synthetic Mucor media. On PDB, pycnidia were formed in hard black aggregates. Spore production in fermentors was similar to that in shaken cultures. The omission of glucose from PDB caused a great increase in the number of spores formed. Also, PDB prepared with the broth of 100 g (instead of the usual 200 g) peeled potatoes/L was effective in spore formation and maintained spore infectivity as high as in controls. It seems that the broth of boiled potatoes is a simple, efficient, and nonexpensive medium for mass production of infective A. quisqualis spores. Key words: Ampelomyces quisqualis, pycnidial production, spore formation, biological control, powdery mildew.

Growth characteristics of selected thermophilic strains of cyanobacteria using crossed gradients of temperature and light

Biologia ◽  
2013 ◽  
Vol 68 (5) ◽  
Author(s):  
František Hindák ◽  
Jana Kvíderová ◽  
Jaromír Lukavský
Keyword(s):  
Wide Spectrum ◽  
Thermal Waters ◽  
Hypersaline Lake ◽  
Optimum Temperature ◽  
Tropical Island ◽  
Growth Requirements ◽  
Temperature Requirements ◽  
Optimal Temperature Range ◽  
Lower Irradiance ◽  
Temperature Optima

AbstractGrowth requirements of 10 possibly thermophilic strains of cyanobacteria were compared under a wide spectrum of light and temperature conditions (7–80Wm−2, 12–40°C). The strains were isolated from different localities: six of thermal springs in Slovakia (4 from Piešťany, 2 from Sklené Teplice), one from thermal waters in Rupite, Bulgaria, 2 strains from a hypersaline lake Chott-el-Djerid, Tunisia, and one strain from the tropical island of Cebu, Philippines. Although the crossed gradient unit allowed only sub-optimal temperature range with respect to thermophile definition, i.e. optimum temperature above 45°C, there were difference among the strains. The most thermophilic and high-light tolerant strain was Synechococcus bigranulatus strain Lukavsky 2005/66, with a peak above 45°C; the second was Chroococcidiopsis thermalis strain Hindák 2008/9, and Isocystis sp. strain Hindák 2006/1. The temperature requirements of other strains were similar; the least thermophilic were both Slovakian strains of the genus Hapalosiphon. Growth was not limited below 80 W m−2, except for H. fontinalis strain Hindák 2008/3, which prefers lower irradiance. Hapalosiphon delicatulus strain Hindák 2007/20, isolated from a bark tree on the tropical island of Cebu was rather mesophilic than thermophilic and shade-preferring. The CCA revealed that the ecologically similar strains originated from the same or nearby localities. There were no significant correlations between temperature optima in culture and in nature. Bulgarian and Tunisian strains preferred higher irradiances.

The effects of physical damage on seed production in flowering plants of Saponaria officinalis

1995 ◽  
Vol 73 (2) ◽  
pp. 235-243 ◽  
Author(s):  
Cynthia Lokker ◽  
Paul B. Cavers
Keyword(s):  
Seed Production ◽  
Seed Mass ◽  
Flowering Plants ◽  
The Other ◽  
Control Group ◽  
Untreated Control Group ◽  
Physical Damage ◽  
Defoliation Treatment ◽  
The Individual ◽  
Saponaria Officinalis

Individual flowering ramets in a large riverbank stand of Saponaria officinalis, bouncingbet, were subjected to three damage treatments at anthesis: removal of most flowers, removal of all leaves, and bending of the stem just below the inflorescence. All seeds were collected from ripened capsules of treated plants as well as from a group shaded by a canopy of Convolvulus sepium and from an untreated control group. Seeds from the defloration treatment were significantly heavier than those from the other treatments. In the control, bent stem, and shaded treatments the seed masses were distributed in a bimodal manner, with most seeds forming a normal distribution around a midpoint of 1.5–1.7 mg and a cohort of heavy seeds having a mean mass of 2.5 mg. This heavy cohort (mode) was missing from the defoliation treatment. Of the total variation in seed mass, 36% was among individuals, 54% was among inflorescences within individuals, and only 10% was within inflorescences. This suggests that resources are allocated differentially between capsules at different positions on the inflorescence but almost uniformly within the individual capsule. Key words: defoliation, defloration, bouncingbet, seed production, Saponaria officinalis.

scholarly journals Environmental Control of Flowering in Pennsylvania Sedge

2014 ◽  
Vol 24 (3) ◽  
pp. 301-306
Author(s):  
Esther E. McGinnis ◽  
Alan G. Smith ◽  
Mary H. Meyer
Keyword(s):  
Floral Development ◽  
Environmental Control ◽  
Flowering Plants ◽  
The Other ◽  
Floral Initiation ◽  
Upland Forest ◽  
Native Habitat ◽  
Short Day ◽  
Carex Pensylvanica ◽  
Achene Production

Pennsylvania sedge (Carex pensylvanica) is an upland forest sedge with restoration and horticultural potential as a low-maintenance groundcover for dry shade. For large landscape and restoration plantings, seed or achenes in this case are much preferred due to lower labor and material costs. However, pennsylvania sedge typically produces few achenes in its native habitat. As a first step in improving achene production, this research evaluated the effect of vernalization and photoperiod on floral initiation and development. We conclude that this sedge is an obligate short-day plant that does not require vernalization for flowering. Plants flowered when exposed to daylengths of 6 to 12 hours. Flowering was completely inhibited with 14-hour photoperiods. Pennsylvania sedge was florally determined after 4 weeks of 8-hour photoperiods. Inflorescence quantity and normal floral development varied by clone and by weeks of exposure to 8-hour photoperiods. For two of the clones, the largest number of normal monoecious inflorescences was produced with 8 to 10 weeks of 8-hour photoperiods while the other two clones only required 6 to 8 weeks of exposure to inductive photoperiods. Therefore, it is important to evaluate observable variation between clones when attempting to propagate pennsylvania sedge.

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