63 research outputs found
Biology and management of freesia flower specking caused by Botrytis cinerea
No full textThere is no published research regarding postharvest infection of freesia flowers
by Botrytis cinerea. Although, infection problems have concerned freesia growers and
wholesalers in recent years. The overall objectives of this study were firstly to evaluate
the factors affecting B. cinerea postharvest disease establishment and secondly to
evaluate a range of novel potential treatments to reduce postharvest freesia infection.
These treatment options include plant activators such as acibenzolar-S-methyl and methyl
jasmonate and biotic (Aureobasidium pullulans) and abiotic (UV-C irradiation)
biological/elicitors agents.
Research was undertaken in an attempt to explain the variation in B. cinerea
incidence on cut freesia flowers as noted by the UK importer Zwetsloots & Sons Ltd. in
2000. Higher monthly rejections of freesia flower stems throughout 2000 due to B.
cinerea infection were recorded during spring (April-May), early summer (June) and
autumn (October). Comparatively higher proportions of rejected freesia stems were
associated with glasshouse temperatures ranging from 13-17°C.
In the presence of B. cinerea inoculum on freesia petal surface, temperature was
not a limiting factor for disease establishment. Incubation of artificially inoculated
freesia flowers at 12°C resulted in overall higher disease severity and lesion numbers
compared to flowers incubated at 5 or 20°C. In contrast, relative humidity was the most
important factor for postharvest infection by B. cinerea.
Elicitor based strategies for IPM using the potent activator acibenzolar provided
limited protection of freesia flowers against B. cinerea when applied postharvest.
Acibenzolar significantly reduced disease severity, lesion numbers and lesion diameters
compared to the untreated control when applied at 0.15 g A. 1. U1.
Methyl jasmonate (MeJA) applied as gas, pulse and spray generally suppressed B.
cinerea disease on cut freesia flowers. Disease severity, lesion numbers and lesion
diameters of flowers gassed with 0.1 μL MeJA L"' were reduced by 56,43 and 37%,
respectively compared to untreated control flowers. Gaseous MeJA treated freesia
flowers at 0.1 μL L"1 increased PPO activity by 57% compared to untreated controls 24h
after MeJA treatment. After 36h of incubation at 20°C, disease severity, lesion numbers and lesion diameters of gaseous MeJA treated flowers were reduced by 68,56 and 50%,
respectively, compared to the untreated controls. However, PAL activity in MeJA treated
freesia flowers did not decrease significantly over time compared to untreated control 12h
post-inoculation and thereafter. These findings suggest that MeJA treatment might
suppress the action of PAL in the phenylpropanoid pathway and consequently block SA
production.
UV-C irradiation might be used in an integrated postharvest disease management
program for freesia flowers. UV-C irradiation after artificial inoculation resulted in
markedly reduced B. cinerea disease severity scores and lesion numbers. In detail, UV-C
irradiation of cut freesia flowers with 0.5,1,2.5 and 5 kJ m''` reduced disease severity by
up to 44,70,74 and 59% and lesion numbers by up to 37,62,68 and 60%, respectively.
UV-C irradiation at 1 kJ M-2 before artificial inoculation slightly reduced disease severity
and lesion numbers possibly by inducing defence responses. However, the limited
disease suppression suggested that apparently B. cinerea could overcome the UV-C
induced effect.
The effect of preharvest treatments on freesia crops with acibenzolar was
investigated in glasshouse trials in view to suppress postharvest B. cinerea infection via
SAR induction. Acibenzolar was effective in selected treatments and conditions.
Disease pressure varied over the 3 years and over varieties tested. However, it was
unclear whether acibenzolar induced systemic and/or local defence responses. The latter
was supported by biochemical investigations in 2001 which suggested that acibenzolar
did not induce PAL activity.
In contrast, preharvest MeJA treatment resulted in markedly systemic protection
of treated flowers compared to untreated ones. MeJA efficacy was dependent on variety
and on postharvest incubation temperatures. Disease severity, lesion numbers and lesion
diameters on MeJA treated freesia var. `Dukaat' flowers incubated at 20°C were reduced
by 56,61, and 49% compared to controls, respectively. Also, disease severity, lesion
numbers and lesion diameters on MeJA treated `Cote d'Azur' flowers incubated at 20°C
were reduced by 36,26, and 49% compared to controls, respectively
Melatonin induces proline, secondary metabolites, sugars and antioxidants activity to regulate oxidative stress and ROS scavenging in salt stressed sword lily
No full textSword lily is regarded as a useful and commercially demanding cut flower crop; hence, assessing its responses to abiotic stress, particularly salt stress, is vital. Melatonin (MT) exhibits stress tolerance in crop plants and is an emerging stress relieving alternative to chemicals. Nevertheless, the possible process underlying the effects of MT under salt stress has yet to be fully elucidated in plants. Herein, the salt stress (SS) mitigation potential of MT was assessed in a commercially important cut flower, sword lily. Melatonin, expressed as MT1, MT2, MT3, and MT4, was administered at concentrations of 0.2, 0.4, 0.6, and 0.8 mM. The results revealed that SS (5 dS m−1) restricted the growth and physiological aspects of sword lily. Furthermore, malondialdehyde (MDA), hydrogen peroxide (H2O2), membrane permeability, endogenous proline, and soluble protein contents were enhanced in SS. MT application improved morphological traits, photosynthetic pigments, and corm traits. The application of MT mitigated the effects of SS stress in Gladiolus grandiflorus plants by improving growth and photosynthetic pigments. MT application under SS improved the reducing and non-reducing sugar and NPK contents of the sword lily. Furthermore, MT improved the levels of secondary metabolites, such as anthocyanins, flavonoids, and ascorbic acid, in sword lily. Moreover, MT supplementation ameliorated salt-induced oxidative stress in the gladiolus, as depicted by a decrease in stress markers (EL, MDA, and H2O2) and an increase in defense-related enzymes (POD, CAT, and SOD) with highest increase in the MT3 treatment under salinity stress. The SOD and CAT enzyme activities were 3–3.6-fold higher in the MT3 under stress than the control. In conclusion, MT applications on cut flowers can be an effective strategy to reduce salt stress and can be used to regulate salinity stress in cut flower production. MT can be used as a safe alternative to other agrochemicals to maintain the growth and flower quality of sword lilies, with beneficial effects during vase life
Overview of the Dynamic Role of Specialty Cut Flowers in the International Cut Flower Market
No full textThe global cut flower industry has faced serious challenges over the years, but still remains an important sector of agriculture. Floriculture businesses seek new, innovative trends and niches to help increase product sales. Specialty cut flower (SCF) production has increased in the past 20 years in the US, Australia, Africa, and Europe. SCF production and sales could increase further if these new products were supported by dynamic marketing campaigns that focus on their strengths compared to the traditional cut flowers (TCF) such as roses, carnations, gerberas, and chrysanthemums. The major strength of SCF is the eco-friendly profile, which is associated to low CO2 footprints and environmental outputs. This contrasts TCF cultivation, which is associated to high energy inputs, especially at the traditional production centres (e.g., The Netherlands). It is suggested that environmental legislations, production costs, and customer demand for eco-friendly products will positively affect future SCF cultivation and sale
Implementation of Sustainable Practices to Ornamental Plant Cultivation Worldwide: A Critical Review
No full textOrnamental production worldwide has changed dramatically in the past 20 years. A globalized scene has shifted production to new countries from Africa, Asia, and South America. Sustainability is the major challenge for ornamental production, and the life cycle assessment (LCA) provides insights on environmental contributions from production to handling and transportation and highlights the problematic issues that need improvement. For example, greenhouse gas (GHG) emissions and the production costs of roses in different parts of the world may vary dramatically between different production processes (e.g., heated or non-heated greenhouses, with or without air transportation, etc.). On the other hand, the production of landscape plants has the lowest environmental impact of all floricultural products. Their long production period offers carbon sequestrations that reduce the total GHG emissions. Sustainability is achieved via critical adjustments on cultivation by minimizing fuel and electricity use, adopting integrated nutrient management (INM) and integrated pest and disease management (IPDM), and using recyclable materials and peat-alternative growing compounds. In this review, two possible scenarios were proposed for ornamental production. Scenario I suggests conventional, protected cultivation under controlled environments (i.e., greenhouses), which can be sustainable after implementing appropriate adjustments to reduce environmental outputs. Scenario II suggests the cultivation of native and specialty ornamental crops, which may serve as eco-friendly alternatives. Combinations between the two scenarios are also possible in view to implement sustainable practices and meet future consumer needs
Au-delà des avant-gardes. Lettre au jeune poète que je me sens redevenir au retour d’un voyage en Europe centrale
No full textThis paper is simultaneously reflexive, polemic and poetic as it raises the central issues of poetry’s status in today’s world. The author expresses his discomfort with the devaluation of the poetic text in times of the merchandization of culture and of the transformation of presses into business ventures. He also worries about the increasing isolation of an elitist poetry based on hermeticism and confidentiality. He takes the reader back to a European tradition, found in Rilke notably, that assigns other missions to the poem. Committed to its present times and its political and economic conditions, poetry must battle on the same grounds as all the arts to address an audience beyond the narrow circles of poetry specialists. Through the invention of new forms that coincide with today’s world, such as slam poetry, the poem can find (again) the channels of its widest distribution, whereby the poet opens new ways and discovers new orders
UV-C irradiation induces defence responses and improves vase-life of cut gerbera flowers
No full textManifesto for ‘spirit of place’: the expressive value of signage on Belfast’s arterial routes in representing wider environmental and societal themes.
No full textThis book chapter builds on a previous journal article submitted to MEI (Mediation Et Information) Design et communication, Paris, France. Commercial signage has a greater presence than any other type of sign in the built environment of cities, conveying a rich tapestry of semiotic codes. Interpreters of signs decode visual information according to their abilities, experiences and needs, but are likely to recognise familiar cultural codes. Signage located within communities must speculate the probability of adequately communicating with those who will purchase goods or services. Commercial signage is often representative of informal community relations, with the spoken language of place gaining physical form through letterforms and cultural connotations expressed through colour and other associated codes. This paper examines signage in the built environment of Belfast’s arterial routes. Photographs demonstrate how various local signs can provide a rich resource for interpreting socio-economic, cultural and political underpinnings of place. RESEARCH HIGHLIGHTS• This work contributes to the body of knowledge on signage; how words, letterforms, expression of language, location of signs, express wider environmental themes of place. • While the research area is in Belfast, the methodology may be applied to any city to reveal underlying themes of place. • The methodology involves fieldwork; signage is photographed and archived, then analysed for graphic and cultural codes. Photographs are by the author and contribute to a growing archive of images established from 2010, numbering in the thousands. Both the research and image archive are of value to the growing body of knowledge on the image of the city. Work allows for positioning of further research by this and other researchers. • Themes investigated are significant and research has been conducted rigorously and with integrity. Research, writing, photographs, maps, for this output are the work of the author and researcher Ruth Brolly.<br/
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