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An Experiment was conducted during growing 1/7/2010 until 30/5/2011. in a private nursery at Hilla governorate (Jannata Ahlam), to study the effect of foliar application of PRO.SOL nutrient solution and Liquorice extract on growth and flowering of Geranium (Pelargonium zonale L). Cultivar Hans Rigler.was experiment included test of three concentrations of Nutrient Solution PRO.SOL (0.0,1.0 and 1.5) g.L­¹ and three concentrations of Liquorice Extract (0,1.5 and 3.0)g.L­¹. The Experiment conducted as a Factorial Experiment Randomized Complete Block Design (R.C.B.D).Duncans Multiple Range test was used at probability of 0.05 to compare means. Results revealed that the interaction between Nutrient Solution of PRO.SOL at concentration of (1.5) g.L­¹ and Liquorice Extract concentration of (3.0) g.L­¹ significantly increased in this parameters ( leaf area, leaf contents of total chlorophyll, total carbohydrate solubility, leaf content of nitrogen, phosphorus, zinc, number florets.plant­­¹, dry weight of florets and content flowers of anthocyanin by increasing percentage 35%, 25%, 19%, 15%, 71%, 44%, 48% and 27%, 31% and 32% and 46% and 41% for two period first and second respectively, Meanwhile, result revealed that the interaction between Nutrient Solution PRO.SOL at concentration of (1.5) g.L­­¹ and Liquorice Extract concentration of (1.5) g.L­­¹ significantly increased total branch number and shoot dry weight by increasing percentage 20% and 18% as compared to least values in the control treatment.

The purpose of this study was to assess the possibility of using compost made from post-consumer wood in zonal pelargonium (Pelargonium zonale) cv. ‘Tex Mex’ cultivation. The influence of compost on the plant’s development and nutritional state, as well as the microbiological and enzymatic activity of the substrate was examined. Two variants of compost marked with the following letters: OPA and OPB were used. Both variants consisted of post-consumer wood waste (OP) (70% of weight) mixed with powdery waste from processing MDF boards (6%), mature compost from fiberboard waste (19%), high peat (4%), water and a biological inoculum “Activit Las”. Thirty kilograms of urea in two portions per prism were added to the OPA variant while ammonium nitrate (1.5 kg per prism), magnesium sulphate (0.4 kg per prism), potassium phosphate (0.8kg per prism) and calcium phosphate (0.9 kg per prism) were added to the OPB variant. The plants were cultivated into pots 12 cm in diameter and a capacity of 659 dm3 in the substrates consisting of peat with the addition of compost at different volume ratios. It was found that the medium type had a significant influence on the growth and flowering of the zonal pelargonium. The type of compost used was the determinant for microbiological total counts and activity. The chemical composition of the substrates significantly modified the plants’ nutritional state in terms of macro- and microelements. In summary, the study demonstrated that good quality ornamental plants can be successfully grown in peat substrate containing 25% or 50% of post-consumer wood compost.

The aim of this study was to assess EDTA-assisted Pb and Cd phytoextraction potential of locally grown Pelargonium hortorum and Pelargonium zonale. Plants were exposed to different levels of Pb (0-1500 mg kg

The ethylene receptor etr1-1 (ETHYLENE RESPONSE 1) mutant gene from Arabidopsis thaliana, with its expression under the control of either the Petunia floral binding protein FBP1 promoter or the Arabidopsis senescence-specific SAG12 gene promoter, was introduced into Pelargonium zonale cv. ‘Katinka’. The heterologous expression of these transgenes and the response of flowers and leaves to exogenous ethylene were then studied. Transgenic etr1-1 lines grown in the greenhouse did not differ morphologically or physiologically from nontransformed plants nor was the rooting ability of cuttings affected. Reverse transcription (RT)-PCR revealed that transcripts from an FBP1 promoter were present from green tissue to the roots, whereas the SAG12 promoter was only active in processes associated with aging or senescence of flower petals and leaves. The sensitivity to ethylene exposure was markedly reduced by using both promoter constructs. Flower petals from nontransformed controls were fully senescent 4 days after ethylene exposure, while more than 90% of the flower petals from FBP1-promoter lines and over 50% of the flower petals from SAG12-promoter lines remained unchanged, without showing any signs of wilting or any response to ethylene. However, ethylene sensitivity of leaves was only delayed in the best lines but not suppressed through etr1-1 expression. Foliage displayed less intense leaf yellowing and wilting, which were similar for both promoter variants compared to wild type controls.

This research evaluated green waste compost (GWC) and green waste vermicompost (GWV) as peat substitutes in growing media used for the production of geranium (Pelargonium zonale L.) and calendula (Calendula officinalis L.). Five growing media were prepared: 100% Peat (P), 50% Peat + 50% GWC (PC), 100% GWC (C), 50% Peat + 50% GWV (PV), and 100% GWV (V). Geranium and calendula seedlings were transplanted into each medium and were grown under commercial nursery conditions for 6 months, i.e., until they attained commercial size. The higher percentage of GWC and GWV in the growing medium could increase bulk density and air space; decrease total pore space and water-filled porosity; and increase pH, electrical conductivity, and macro- and microelement contents. The heavy metal contents of all growing media were within safe ranges. Particle-size distribution and fertility were superior in the vermicompost-based media than in the compost-based media. Geranium growth was reduced in media containing GWC (C and PC). Calendula growth in compost-based growing media was similar to or greater than growth in pure peat. Geranium and calendula growth and flowering were superior in all vermicompost-based media (PV and V) than in the control medium (P). These results indicate that GWV is better than GVC as a partial substitute for peat in the cultivation of geranium and calendula.

Combined with multilayer system, apply LED light in specific production phase of ornamentals makes it possible to study the effects of light quality on its physiological performance and plant-water relations. As plants will continue their growth in the in a drastic changing greenhouse environmental afterwards. In this study, Pelargonium zonale, Cordyline australis and Ficus benjamina were selected and grown under four light qualities: white (W, 420-700 nm), blue (B, 460 nm), red (R, 660 nm) and 50% blue + 50% red LED (RB) with light intensity at 100 µmol m-2 s-1. Effects of light quality on parameters related to photosynthesis (chlorophyll, CF parameters) and plant water relations (stomatal density, stomatal conductance) were studied. We found no general effect of light quality on pigment biosynthesis of the studied species. In Pelargonium zonale, the highest chlorophyll content was obtained under W and the lowest under B, while for Cordyline australis, the highest content was found under RB and the lowest under R, for Ficus benjamina not effect of light quality was found. Chlorophyll fluorescence kinetic parameters showed similar trends for the three ornamentals. The quantum yield as well as the photochemical quenching was highest under B or RB while lowest values were found under R. Light quality also affected leaf stomatal density and conductance though effects were species dependent. Cordyline australis had the highest stomatal density under W while no effect of light quality was found for Pelargonium zonale the highest stomatal conductance was found under B.

The study evaluated the feasibility of simplified hydroponics for the growth of rooted cuttings of geranium (Pelargonium zonale) for commercial purposes in local farms in Northern Italy. Tested systems included a control where soilless system on substrate (peat) (T-1), usually adopted by local farmers, was compared against an open-cycle drip system on substrate (peat) (T-2), and a Nutrient Film Technique system (T-3). For commercial features, assessed parameters included flowering degree (flowering timing, numbers of inflorescences plant&minus, 1, and number of flowers inflorescence&minus, 1), numbers of leaves plant&minus, 1, number of branches plant&minus, 1, final height of plant, and the aesthetic-commercial assessment index. Assessed parameters also included fresh and dry weight, SPAD Index, the water consumption, and the water use efficiency (WUE). The soilless systems typology significantly affected rooted cuttings growth, commercial features, and WUE. The adoption of an open-cycle drip system (T-2) resulted in a significant improvement of all the crop commercial characteristics as compared with other treatments, making plants more attractive for the market. The water consumption was higher in T-2 as compared with T-1 and T-3, but it allowed for the highest fresh weight, and therefore also the highest WUE. The results indicate that the typology of soilless system significantly enhances the commercial characteristics of geranium.

Geranium plants were cultivated in a growth chamber with different light quality and microorganism inoculation conditions. The long-term effect of irradiance quality (LED and fluorescent) as well as two types of microorganism treatments on photosynthetic activity parameters was examined. The maximum reached values of net photosynthesis rate ( P N ), stomatal conductance ( g s ), transpiration rate ( E ) and intercellular CO 2 concentration ( C i ) were afterwards measured in plants cultivated under six colours of light – white, white-blue, blue, red, red-blue and green – emitted by two types of lamp: LED and fluorescent. Two types of microorganism treatments were used: BAF 1 created in the Department of General and Environmental Microbiology and the commonly used Effective Microorganisms (EM) biopreparation. A highest level of P N were found in plants after cultivation under white-blue light (both – fluorescent and LED) and treated by BAF 1 . The positive effect of EM was only noted in the case of plants cultivated under blue-red fluorescent light. Considering plants without microbial inoculation the highest levels were recorded in plants under red and blue light. The comparison of the effect of light quality revealed that in all colours a higher or similar level of net photosynthetic rate was noted in plants under LEDs. Mostly the higher photosynthetic activity was connected with higher stomatal opening as well as with higher transpiration rate, which is especially true for plants cultivated under red and blue LED light.

Pelargonium zonate spot virus (PZSV) was first reported on Pelargonium zonale (L.) L'Hér. ex Aiton and later on tomato in Italy, Spain, France (1), and the United States (2). In Spain, PZSV was first detected in 1996 in tomato plants of cv. Royesta from greenhouses in Zaragoza Province (3) and subsequently in tomato in the Catalonia and Navarra areas. In April 2006, symptoms of PZSV were found at high incidence on tomato in a greenhouse in Huesca, Aragón (northeastern Spain). Randomly distributed pepper plants (Capsicum annuum L.) of cv. Estilo F1 growing in the same greenhouse showed severe foliar chlorotic ringspots and line patterns similar to those observed in tomato. Samples from symptomatic peppers and tomatoes and one asymptomatic weed of Rubia tinctorum L. tested positive by double-antibody sandwich (DAS)-ELISA using polyclonal antibodies against PZSV (Agdia Inc., Elkhart, IN and DSMZ, Braunschweig, Germany) as did a Spanish PZSV isolate used as a positive control (3). Sap extracts from two tomatoes, three peppers, and the single R. tinctorum plant were mechanically inoculated to 22 indicator species, including pepper and tomato. On 17 of 22 species inoculated, sap from symptomatic tomatoes and peppers elicited local or systemic symptoms similar to those reported earlier for PZSV isolates (3). Systemic symptoms were mainly mosaic, chlorotic, and necrotic line patterns and ringspots on leaves of most indicator species, closely resembling those observed on the greenhouse pepper and tomato plants. Symptoms on inoculated tomatoes also included stem necrosis and death. Reactions of indicator species did not indicate the presence of any other pepper- or tomato-infecting viruses. Both field infected and mechanically inoculated plants of pepper cvs. Yolo Wonder and Doux des Landes were maintained in the greenhouse until the development of fruit symptoms. Only fruits of cv. Yolo Wonder showed dark green and slightly depressed circles on their surface. Local and systemic infection by PZSV was confirmed by DAS-ELISA in most inoculated plants. Total RNA from leaves of field or inoculated plants was used as template for amplification by reverse transcription (RT)-PCR with primers R3-F and R3-R that are specific for the PZSV 3a gene (2), and amplicons were sequenced directly. The sequences of 697 nt from pepper and tomato isolates from the same greenhouse were identical (GenBank Accession Nos. CQ178217 and CQ178216, respectively) and had 96.1% identity to nucleotides 384 to 1,080 in PZSV RNA-3 (NC_003651). Our results confirm the natural infection of pepper plants in Huesca by PZSV. To our knowledge, this is the first report of pepper as a natural host for PZSV, a significant finding considering the potential risks of PZSV dispersion whenever tomato and pepper coexist, particularly in greenhouses and nurseries. References: (1) M. Finetti-Sialer and D. Gallitelli. J. Gen. Virol. 84:3143, 2003. (2) H. Y. Liu and J. L. Sears. Plant Dis. 91:633, 2007. (3) M. Luis-Arteaga and M. A. Cambra. Plant Dis. 84:807, 2000.

Geranium leaves and stems with symptoms of bacterial blight were collected from commercial greenhouses during the last decade in Serbia. In total, 17 isolates with colony morphology typical for the genus Xanthomonas were characterized with pathogenicity, biochemical, serological, and molecular assays. All 17 isolates reacted positive in a polymerase chain reaction (PCR) using XcpM1 and XcpM2 primers specific for Xanthomonas hortorum pv. pelargonii. In pathogenicity tests on Pelargonium zonale (leaf and stem inoculation), all isolates caused typical symptoms on leaves starting 2 days after inoculation as sunken, water-soaked, irregular lesions, and 6 to 8 days after inoculation on stems as necrotic lesions also showing yellow exudate. Symptoms resulted in general wilting of inoculated plants 20 days after inoculation. Selected phenotypic tests indicated that all isolates showed the same results as described for the bacterium X. hortorum pv. pelargonii. Repetitive sequence-based PCR typing using BOX and ERIC revealed that all isolates showed two fingerprinting profiles but (GTG)5 and REP did not reveal differences. Multilocus sequence typing of partial sequences of rpoD, dnaK, fyuA, and gyrB genes of tested isolates and sequences obtained from GenBank of Xanthomonas pathovar pathotype strains did not reveal genetic variability among the isolates, showing the same gene sequence pattern.

Aquaculture effluent can supply certain plant nutrients in adequate amounts. However, the nutrients present in the fish waste solution are not balanced. Mixing this effluent in an independent unit with a hydroponic nutrient solution can help to optimize conditions for the plants and minimize such drawbacks. The objective of this work was to assess the crop production and the nutritional responses of Pelargonium zonale fertigated with different percentages of fish wastewater. Five treatments were performed: 100NS, 75NS + 25AS, 50NS + 50AS, 25NS + 75AS and 100AS, where AS is the fish wastewater and NS a hydroponic nutrient solution. The species used to provide the fish waste solution was tilapia nilotica (Oreochromis niloticus). The results of this assay show that: i) fish wastewater can be utilized for the fertigation of Pelargonium zonale (a short-cycle crop) as there are no differences in the leaf, stem-petiole and flower dry matter, leaf water content, leaf area, plant height and leaf color compared to Pelargonium zonale fertigated with a chemical fertilizer; ii) the application of 75NS + 25AS accelerated flowers, shoots and leaves production. A higher percentage of fish waste solution mixed with the applied nutrient solution significantly reduces the K concentration in the nutrient solution and in the leaf; however, tilapia waste solution supplies adequate N, P and Ca nutrients to the pelargonium plants. Therefore, the reuse of fish waste solution can reduce the application rate of some inorganic fertilizers, which in turn can reduce the cost of fertilizers while preventing environmental pollution.

SummaryLeaf senescence and petal abscission in flowering plants such as Pelargonium occur in the dark during commercial transportation. Both affect plant quality and the commercial viability of the plant. In this experiment, we investigated the effects of 60 mg l 1 silver nanoparticles (SNP) in combination with 75 µM thidiazuron (TDZ) on selected physiological and biochemical characteristics of four cultivars of Pelargonium zonale (‘Foxi’, ‘Flowerfairy’, ‘Bluewonder’, and ‘Anthony’) incubated in the dark.The concentrations of photosynthetic pigments and proteins were measured, and petal abscission and anti-oxidant enzyme activities were analysed under the treatments applied. Following exposure to SNP plus TDZ, the extent of lipid peroxidation as well as superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) activities changed, together with changes in the isozyme patterns of POD and SOD. SNP plus TDZ significantly decreased the incidence of petal abscission and leaf s...

Influences of night interruption (NI) application timings were examined on vegetative growth and flowering of Dianthus chinensis (quantitative long-day plant), Zinnia elegans (quantitative short-day plant), and Pelargonium zonale (day-neutral plant). The experiments were conducted both in a greenhouse and in a growth chamber. In both experiments, plants were grown under 9 hours photoperiod [short-day (SD) condition] or 9 hours photoperiod plus 4 hours NI with low light intensity at a photosynthetic photon flux (PPF) of 3–5 μmol m−2 s−1. The NI was employed at 18:00–22:00 HR (NI18), 22:00–02:00 HR (NI22), or 02:00–06:00 HR (NI02). Net photosynthesis of Dianthus during the NI period was determined in the growth chamber experiment. In Dianthus, node number increased more rapidly in all NI treatments regardless of the timing of NI. The height of Zinnia was shorter under NI than under SD, and those grown under NI02 were shorter than those under NI18 or NI22. In Pelargonium, leaves of the plants grown under NI02 were produced more slowly than those of the plants under NI18 and NI22. For these three species, dry weights of the plants under NI were not significantly different from those of the plants under SD. The NI had no effect on net photosynthesis of Dianthus. Flowering of Dianthus was hastened by all NI treatments, more in NI02 than in NI18 or NI22. Zinnia flowered later under NI02 than under NI22 or NI18. Flowering of Pelargonium was not affected by the NI application timing. These results indicate that NI02 was most effective in promoting flowering in Dianthus or inhibiting flowering in Zinnia. However, the NI with low light intensity at 3–5 μmol m−2 s −1 PPF had no significant effect on net photosynthesis and subsequent dry matter accumulation in these three herbaceous plants.

This investigation was conducted to evaluate the effects of post-harvest application of silver nanoparticles (N-Ag) and dark storage on plastid pigments, petal abscission, lipid peroxidation and activities of ascorbate peroxidase (APX) and guaiacol peroxidase (POD) in pelargonium cultivars ‘Blue Wonder’ and ‘Anthony’. N-Ag was applied as foliar spray in concentrations 0, 20, 40, 60 and 80 mg·cm-3 and then the plants were stored for 5 days in a growth chamber in darkness at temperature 20±2 °C and relative humidity 65%. The results revealed that after dark storage the petal abscission of cv. ‘Blue Wonder’ increased up to 40% but significantly decreased in plants treated with 60 mg·cm-3 of N-Ag. Cultivar ‘Anthony’ showed lesser petal abscission than ‘Blue Wonder’, namely 25% in control and 4% after treatment with 60 mg·cm-3 N-Ag. In both cultivars, treatment with N-Ag resulted in higher contents of leaf chlorophylls and carotenoids in comparison to untreated control. In response to treatments with 20-60 mg·cm-3 N-Ag, the activity of APX and POD was higher at the end of 5 days storage period than in the control plants, which coincided with improved post-harvest performance of both pelargonium cultivars. The enhancement of enzyme activities indicated possible beneficial effect of the applied treatment on alleviation of dark storage-induced oxidative stress. Also, in both cultivars, MDA content decreased significantly with the increase of N-Ag concentration up to 60 mg·cm-3 and then a rapid increase at 80 mg·cm-3 followed. It is concluded that treatment with silver nanoparticles is effective for preventing dark storage-induced petal abscission of pelargonium.

Ornamental plant variety improvement is limited by current phenotyping approaches and neglected use of experimental designs. The present study was conducted to show the benefits of using an experimental design and corresponding analysis in ornamental breeding regarding simulated response to selection in Pelargonium zonale for production-related traits. This required establishment of phenotyping protocols for root formation and stem cutting counts, with which 974 genotypes were assessed in a two-phase experimental design. The present paper evaluates this protocol. The possibility of varietal improvement through indirect selection on secondary traits such as branch count and flower count was assessed by genetic correlations. Simulated response to selection varied greatly, depending on the genotypic variances of the breeding population and traits. A varietal improvement of over 20% is possible for stem cutting count, root formation, branch count and flower count. In contrast, indirect selection of stem cutting count by branch count or flower count was found to be ineffective. The established phenotypic protocols and two-phase experimental designs are valuable tools for breeding of P. zonale. Breeding techniques developed for crop species can be used on ornamental plants like Pelargoniums to enhance desired traits. A team led by Heike Molenaar from the University of Hohenheim in Stuttgart, Germany, used a two-phase experimental design, combining observations from two different locations, to improve production-related traits in a Pelargonium shrub species indigenous to South Africa called Pelargonium zonale. The researchers measured stem cutting count, root formation, flower count and branch count in hundreds of plants with different genetic makeups in two different greenhouse settings. They calculated the degree of genotypic diversity in these traits and the extent to which these traits shared common genetic underpinnings. They used these measures to simulate responses to selection and found that flower count, branch number and other desired traits could be increased by more than 20%.

The importance of green areas is increasingly considered for the restoration of polluted urban ecosystems. This subject represents an emerging area of research gaining a commercial significance in the field of environmental biotechnology. In this context, phytoremediation appears to be a promising technique for metal soil cleanup especially where the area has little or no alternative uses. Ornamental plants can be used for this purpose in urban design, where both environmental and aesthetical solutions are needed. A two years pilot study for evaluating the suitability of herbaceous ornamental species to evaluate the attitude of some herbaceous ornamental species as metals bioaccumulators in urban low contaminated soils was carried out. The experiment was carried out in Asti (Italy). Eight species and cultivars have been tested: Helianthus annuus L. ‘Zebulon’, Helianthus annuus L. ‘Nano Semplice – Mix’, Silene vulgaris (Moench) Garcke, Alyssum argenteum All., Alyssum saxatile L. ‘Sulphureum’, Brassica juncea L., Pelargonium sp. ‘Frensham’ and Pelargonium zonale L. Three plots for each species were planted. Physical-chemical characteristics of top soil before and after the experiment were determined. After harvesting, metals contents in plants were measured. Results indicated that metal concentration varied according to the different part of the plants and to the different species and cultivars. Alyssum, Pelargonium ‘Frensham’ and Helianthus appeared to be the most suitable. The use of phytoremediation techniques in urban soils can be an interesting method to control metals accumulation in time. Further studies are required in order to find new ornamental species useful in urban green areas and to evaluate proper methods for their disposal.

Pelargonium ( Pelargonium x hortorum ) is grown as potted or bedding plants for their colourful, showy flowers and scented foliage. Absence of senescence symptoms in the leaves of Pelargonium cuttings, their capacity to initiate roots and continued growth of initiated roots is an important quality attribute. The effects of postharvest treatments with meta-topolin (mT) and thidiazuron (TDZ) to ‘Katinka’ Pelargonium cuttings were investigated. Leaves treated with mT or TDZ for 5 d had higher leaf chlorophyll contents than untreated controls. Exposing cuttings to mT had no effect on the rooting proportion (%) and average root diameter. Similarly, 0.05 mM mT had no effect on number of roots per cutting. However, mT slightly reduced root length, root surface area and total volume of the roots. TDZ severely inhibited adventitious root formation, thus it reduced all the root parameters investigated. In conclusion, mT is very active in retarding leaf senescence, and combined with the observed ease of rooting of cuttings after mT treatment, this treatment is a suitable alternative to TDZ in delaying the onset of leaf yellowing in ornamental crops.

The composition and antimicrobial activity of the essential oil of leaves and flowers of Pelargonium zonale L. cultivated in Egypt were investigated. Hydrodistillation of the leaves and flowers yielded 0.12% and 0.06% (v/w of fresh plant) of yellowish green essential oils, having a sweet balsamic odor. GC-MS analysis led to identification of 25 and 20 components, based on retention indices and mass spectral data, representing 97.0% and 94.8% of the total oils, respectively. Sesquiterpenoids were predominant in the two oils (73.9 and 81.9% of the constituents) with hydrocarbons as major (51. 8% and 63.5%) followed by oxygenated components constituting 22.1% and 18.3%, respectively. On the other hand, monoterpenoids reached only 7% and 5.8% among which hydrocarbons constituted 7% and 1.67%, respectively, of the total oils; while oxygenated compounds (2.6%) were detected only in the flower sample. The essential oil of the leaves was typified by the presence of β-caryophyllene (24.6%), α-humulene (23...

The effects of Lantana camara (leaves), Pelargonium zonale (leaves), Cupressus macrocarpa (leaves), Cyperus rotundus (whole plant) and Acacia nilotica (seeds)powders on some biological aspects of house fly, M. domestica L. were tested. The effects of three lethal concentrations LC25, LC50 and LC75 on the larval duration, pupation percent, pupal weight, pupal duration, adult emergence percent, sex ratio, adult longevity, and fecundity were determined. The induced malformed larvae, pupae and adults were recorded and photographed. The powders of the five plants were found to have promising effects in controlling this insect.

N,N-dipropyl(1-cyclopropenylmethyl)amine (DPCA), a non-volatile derivative of 1-MCP (1-methylcyclopropene), was synthesized in salt form and tested for effectiveness in preventing ethylene responses in various ornamentals. Individual flowers or flower spikes of four ethylene-sensitive plant species: miniature rose, geranium, carnation and orchid were sprayed with different amounts of DPCA in the range of 0-40 nmol and the effectiveness of DPCA was compared with 1-MCP treatment, a volatile application form. After chemical treatments the plant material was exposed to 1 μl L -1 ethylene and the postharvest performance of flowers evaluated. This study proved that DPCA can be effective at blocking ethylene action when applied as a spray.

Cyclopropene compounds have been shown to counteract ethylene responses in plants in many studies. They are volatile and for that reason are applied in enclosed systems. However, in some cases, use of a non-volatile formulation would be advantageous. This study reports the use of a novel anti-ethylene formulation, a salt N,N-dipropyl(1-cyclopropenylmethyl)amine (DPCA), applied to plant material as a spray. Four ethylene-sensitive plant species with a high ornamental value: Rosa hybrida L. ‘Lavander’, Dianthus caryophyllus L. ‘Idra di Muraglia’, Pelargonium zonale ‘Katinka’, and Phalaenopsis ‘Lila’ were sprayed with different amounts of DPCA: 0, 0.4, 2, 4, 20 or 40 nmol and the effectiveness of DPCA was compared with volatile 1-methylcyclopropene (1-MCP) applied at 0.2 μL L−1 for 6 h. After chemical treatments the plant material was ventilated with 1 μL L−1 ethylene or with ethylene-free air. Postproduction quality of flowers and leaves was evaluated and ethylene production in carnation flowers was measured. The optimum concentration of DPCA varied among the tested plant material, but the best concentrations gave protection against ethylene equivalent to the 1-MCP volatile treatment. DPCA amounts of 4 nmol or higher effectively prevented ethylene production in carnation flowers during the postharvest period.

Arabidopsis thaliana transgenic plants with constitutive overexpression of the aspartic protease gene At2g28010 (named CDS10) showed a bushy, multi-branching dwarf phenotype. In order to obtain compact plants of ornamental interest with an analogous phenotype in Pelargonium zonale, a tall cultivar (Boda Gitana Salmon) was transformed to over express the A. thaliana CDS 10 gene under the 35S promoter. Twenty seven transgenic lines were obtained with different levels of expression after gold particle bombardment and regeneration. Some of them showed indeed a bushy phenotype with a higher number of branches and a dwarf phenotype. However, an increase in the number of branches correlated with a decrease in the number of petals in the flowers. So the plants that were of interest from the compact habit point of view, had lost the double flower trait, and exhibited only 5 petals/flower which were also smaller than those from double flowers from the non transformed plants. Intermediate phenotypes with semi-double flowers and higher number of branches but without a compact phenotype were also observed. In order to determine if it was genotype related two other cultivars were transformed, Mirada Violet and Mirada Simple Pink double and single flower cultivars respectively. Transgenic plants showed indeed a higher number of branches and single flowers. Even if the busy phenotype was of interest in order to get a higher number of cuttings/plant and a compact phenotype, the pleiotropic effects of the overexpression of the A. thaliana CDS 10 gene on the flowers are too strong meaning it is only of interest in single flowered cultivars which are a small share of the market. (Resume d'auteur)

Plant morphogenesis is strongly affected by light quality. We evaluated the effects of localized blue light irradiation from light-emitting diodes (LED) on the leaf shape of geranium plants, which show epinasty under red light conditions. Geranium ( Pelargonium zonale Ait.) plants with five or six true leaves were transplanted into a growth chamber containing a metal halide lamp (MH) or a red LED panel (R-LED) that irradiated light at an intensity of 100 μmol m −2 s −1 . The fifth true leaves were then subjected to localized irradiation from small LED light sources. Under localized irradiation of blue light at a 50 μmol m −2 s −1 intensity level, the leaf epinasty index, was 20% lower than under localized red irradiation. The extent of the inhibition of leaf epinasty by blue LED irradiation depended on the light intensity. Blue light irradiation to the abaxial sides of leaves did not inhibit leaf epinasty under red irradiation. In response to blue light irradiation to the adaxial side of the fifth true leaf, the leaf angle reached 225° by the end of the experiment, which was larger than the angle reached under red irradiation. In fifth true leaves treated with localized blue irradiation for 6 h during the daytime, the leaf epinasty level was higher than with blue light irradiation for 12 h. The length of epidermal cells of the abaxial sides irradiated with blue light was 7–13% longer than under red irradiation in the absence of blue irradiation. These results suggest that in geranium, leaf epinasty is controlled by cell elongation in the abaxial epidermis triggered by blue light irradiation of the adaxial side of the leaf.

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Anacardic acid (2-hydroxy-6-alkylbenzoic acid) produced and secreted from glandular trichomes of zonal geranium (Pelargonium x hortorum; Geraniaceae family) provides resistance to small pests (aphids and spider mites). To assess the potential bioactivity of anacardic acid against larger insect pests and to determine if an alternate mode of application (ingestion rather than the topical application) could impart resistance to pests, the effects of anacardic acid consumption on the development of Colorado potato beetle larvae were tested. Analysis of dose-response curves indicated a significant effect on weight gain and mortality. Assessment of food preference (treated versus untreated) indicated larvae avoid food containing anacardic acid and have a lower feeding rate on food containing anacardic acid. On the basis of these results, it is suggested that anacardic acid, applied as a chemical spray or through bioengineering production in crop plants, may provide a new tool in the arsenal to minimize damage to plants caused by pests.

Two experiments were completed to determine whether the form and concentration of iron (Fe) affected Fe toxicity in the Fe-effi cient species Pelargonium ×hortorum 'Ringo Deep Scarlet' L.H. Bail. grown at a horticulturally low substrate pH of 4.1 to 4.9 or Fe defi ciency in the Fe-ineffi cient species Calibrachoa ×hybrida 'Trailing White' Cerv. grown at a horticulturally high substrate pH of 6.3 to 6.9. Ferric ethylenediaminedi(o-hydroxy- phenylacetic) acid (Fe-EDDHA), ferric ethylenediamine tetraacetic acid (Fe-EDTA), and ferrous sulfate heptahydrate (FeSO 4 ·7H 2 O) were applied at 0.0, 0.5, 1.0, 2.0, or 4.0 mg ·L -1 Fe in the nutrient solution. Pelargonium showed micronutrient toxicity symptoms with all treatments, including the zero Fe control. Contaminant sources of Fe and Mn were found in the peat/perlite medium, fungicide, and lime, which probably contributed to widespread toxicity in Pelargonium. Calibrachoa receiving 0 mg Fe/L exhibited severe Fe defi ciency symptoms. Calibrachoa grown with Fe-EDDHA resulted in vigorous growth and dark green foliage, with no difference from 1 to 4 mg·L -1 Fe. Using Fe-EDTA, 4 mg Fe/L was required for acceptable growth of Calibrachoa, and all plants grown with FeSO 4 were stunted and chlorotic. Use of Fe-EDDHA in water-soluble fertilizer may increase the upper acceptable limit for media pH in Fe-ineffi cient species. However, iron and Mn present as contaminants in peat, irrigation water, or other sources can be highly soluble at low pH. Therefore, it is important to maintain a pH above 6 for Fe-effi cient species regardless of applied Fe form or concentration, in order to avoid the potential for micronutrient toxicity. The pH of the substrate in container grown crops has a major infl uence on micronutrient solubility (Lindsay, 1979; Peterson, 1981) and their subsequent uptake by plants (Marschner, 1995). If the substrate pH is too high, solubility of the micronutrients, boron (B), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) can decrease to levels unacceptable for growth, causing a defi ciency. If the substrate pH is too low, solubility of these micronutrients can increase to levels that cause toxicity. For most species grown in substrates without soil, a pH range of about 5.8 to 6.2 provides adequate nutrient solubility to meet plant requirements without causing defi ciency or toxicity, although recommendations vary ±0.2 pH units (Bailey and Nelson, 1998; Argo and Fisher, 2002). When Fe uptake is inadequate (usually induced by high substrate pH), the shoot tip can rapidly become chlorotic followed by ne- crosis as the defi ciency becomes more severe (Argo and Fisher, 2002; Miller et al., 1984). In contrast, excess accumulation of Fe (usually induced by low substrate pH) occurs in the lower leaves of the plant. Toxicity symptoms can include chlorotic and necrotic speckling of leaves, leading to complete leaf death (Albano et al., 1996; Argo and Fisher, 2002) through production of free radicals and resulting oxi- dative damage of membranes (Bartosz, 1997; Marschner, 1995). Bedding plants can be classifi ed Fe-effi cient or Fe-ineffi cient based on their ability to ac- cumulate Fe under conditions of limited sup- ply (Romheld, 1987), usually caused by high substrate pH. At high pH (low Fe solubility), Fe-effi cient plants can increase Fe uptake into their tissue using various strategies including acidifi cation of the root zone, extrusion of chelating agents and Fe(III) reductases, and morphological changes to root structure with increased growth of fi ne root hairs (Gueri- not and Yi, 1994; Bienfait, 1988; Romheld, 1987). Iron defi ciency induced by high pH is therefore not generally a problem with Fe-ef- fi cient plants. Instead, low pH induced iron and manganese toxicity is the major concern in Fe-effi cient fl oricultural species, including Tagetes species (marigold) and Pelargonium

Ornamental plants represent a high number of species from different plant families. To investigate the ethylene biosynthesis and isolate the genes involved in each species a fast and simple method is necessary. The enzyme that controls the ethylene synthesis is the 1-aminocyclopropane-1-carboxylic acid (ACC) synthase, which catalyses the formation of ACC, the immediate precursor of ethylene. Cloning of the first ACC synthase genes from different plant species revealed a multi-gene family.By using degenerate oligonucleotides that correspond to conserved amino acid residues of known ACC synthases, we amplified different genomic fragments that encodes ACC synthase homologue DNA fragments. As a result of the intron size variation of ACC synthase genes, the amplification of several ACC synthase genes with only one PCR reaction was possible. By means of this method we were able to isolate several unknown ACC synthase genes in a wide range of ornamental plant species such as Rosa hybrida, Euphorbia pulcherrima, Kalanchoe blossfeldiana, Pelargonium zonale and Campanula carpatica.

An assay system was evaluated for denitrification measurement with potted ornamental plants cultivated in peat substrate (Pelargonium zonale, Euphorbia pulcherrima). Flow-through chambers only enclosing the pot of the plants were considered best for denitrification measurement. Loss of N2O from the chambers by transport through the plant shoot was negligible with both species. To determine (N2O + N2)-N loss, C2H2 was applied to inhibit reduction of N2O. Experiments were conducted with unplanted substrate in closed incubation systems to determine optimum C2H2 concentration and pre-treatment duration. Complete inhibition of N2O reduction in peat substrate was achieved using 1 vol% C2H2. However, a concentration of 5 vol% C2H2 was chosen for further experiments because C2H2 concentrations in flow-through chambers varied. The duration of C2H2 pre-treatment (0, 2, 12, 24 h) showed no clear effect on (N2O + N2)-N accumulation. However, a pre-treatment duration of 2 h was chosen to guarantee immediate inhibition of N2O reductase at the start of experiments. Exposure to C2H2 gas proved to affect plants of both species. During C2H2 exposition in flow-through chambers, the leaves of P. zonale became chlorotic (48 h) and necrotic (72 h). E. pulcherrima showed no chlorosis but did exhibit leaf epinasty (24 h) and wilting (96 h). Transpiration of P. zonale and C availability in the growing medium of both species were not affected by 52 h and 24 h treatments with C2H2, respectively. As N emissions usually ended within 38 h of C2H2 treatment, it was concluded that side effects of C2H2 did not affect denitrification measurements.

The attempts of this investigation were to develop a system for plant regeneration from explants of adult plants and its use for genetic transformation of important commercial Pelargonium zonale hybrid and P. peltatum hybrid cultivars. To this aim, leaf blade and petiole explants of eight cultivars were cultured on modified MS (Murashige and Skoog, 1962) medium with two concentrations of TDZ, BA, and zeatin (5 and 20 μM). Petiole explants showed a higher regeneration response than leaf blade explants and TDZ was the most effective cytokinin. Petioles of 16 cultivars were incubated on medium containing 5, 10, 15, and 20 μM TDZ, respectively, in order to identify the most effective TDZ concentration. For the majority of genotypes 10 μM TDZ resulted in the best regeneration response. Cefotaxim at 500 mg l −1 had no effect on shoot regeneration and did not show interaction with glufosinate. For selection of transgenic cells, a concentration of 2.5 μM glufosinate was shown to be appropriate. LBA4404 and EHA101 Agrobacterium strains carrying pIBGUS vector with pat gene as selectable marker gene and GUS gene as reporter gene were compared in transformation studies. With regard to GUS expression in petiole explants 16 days after coculture, better results were obtained with EHA 101 than with LBA 4404.

The cyanic and acyanic colour of Pelargonium cultivars is the result of the presence or absence of anthocyanins in the flowers. Instead of anthocyanins, acyanic flowers contain different types and amounts of flavonoids leading to white or cream colour. Our aim was to demonstrate the enzymes of the anthocyanin pathway and to identify possible blocks in the main enzymatic steps. We investigated four enzymes, chalcone synthase (CHS), flavanone 3s-hydroxylase (FHT), dihydroflavonol 4-reductase (DFR) and flavonol synthase (FLS). The first three enzymes lead to the production of leucoanthocyanidins, the substrates of the anthocyanidin synthase (ANS), and FLS is responsible for flavonol synthesis. In spite of many examples of testing the above enzymes in numerous species, up to now, Pelargonium proved to be a recalcitrant plant for enzymatic studies. Nevertheless, we detected significant differences in enzyme activity between cultivars and between flower developmental stages of the same cultivar. The acyanic cultivars studied seem to be blocked late in the anthocyanin pathway. Our results may serve as a basis for further genetic and biochemical characterisation of Pelargonium plants.

Pelargonium petal abscission and ethylene-induced leaf senescence are major problems that reduce the longevity of plants. This study was carried out to determine the poststorage influence of nanosilver (NS) particle (0, 20, 40, 60, and 80 mg L-1) application during dark storage period on chlorophyll and carotenoid pigments, malondialdehyde (MDA) content, leaf protein and ethylene concentration, petal abscission, membrane stability index (MSI), and enzyme activity including ascorbate peroxidase (APX), peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), and \BETA-glucosidase (\BETA-GLU) in two Pelargonium pot plants of the cultivars Flowerfairy and Foxi. Enhanced photosynthetic pigment contents were recorded in leaves of both NS-treated cultivars when compared to the control. In both cultivars, MDA content decreased significantly with the increase of NS concentration up to 60 mg L-1, and then a rapid increase followed at 80 mg L-1. NS treatments markedly decreased petal abscission compared to the control. Enzymes activities were affected differently by various NS concentrations. The highest APX activity was observed at 40 mg L-1 NS concentration, but specific activities of SOD and POD increased to a maximum level at 60 mg L-1 in both cultivars. CAT activity was pronounced at 20 mg L-1 and 40 mg L-1 NS treatments in Flowerfairy and Foxi, respectively. Both under control conditions and at the highest NS concentration, \BETA-GLU showed lower activity than other NS levels. It was suggested for the first time that NS extended petal longevity and improved defense enzyme activities of Pelargonium pot plants under dark storage conditions.

In two successive seasons, the effect of treatment of geranium stock plants with the competitive saprophytic fungus Ulocladium atrum as a biocontrol agent against Botrytis cinerea was compared to a fungicide treatment with Euparene M. B. cinerea incidence and severity on the stock plants, B. cinerea spore load in the air around stock plants and death of cuttings due to B. cinerea were scored. B. cinerea incidence and severity were much stronger in the second than the first experiment. This was quantitatively expressed by higher numbers of conidia of B. cinerea monitored in the second than the first year, both on necrotic (a maximum for the control of 27.5 × 106 spores per sample - all necrotic leaves of five plants - in experiment 1 against 86 × 106 in experiment 2) and green leaves, but numbers of conidia of B. cinerea recovered from the air were only slightly different. The death rate of cuttings was moderate in the first and extremely high in the second experiment. For the fungicide treatment, maximum sample values of 7% and 76% of 6-week old cuttings were killed in the first and the second experiment respectively. Treatment with U. atrum was effective in reducing all parameters studied. With the exception of the spore load of B. cinerea in the air and the success of cuttings, the effect of U. atrum varied from as good as the fungicide to half as effective. In the first trial, only Euparene M reduced spore load in the air, in the second trial only U. atrum consistently did so. In the first trial U. atrum reduced death of 4-week old cuttings, though less than fungicide (1.2, 20 and 38% killed with fungicide treatment, U. atrum treatment and control respectively). In the second trial only the fungicide reduced loss of cuttings. The impact of the data on the integration of U. atrum in a control system of B. cinerea in geranium is discussed.

SummaryRooted cuttings of Dendranthema grandiflora Tzvelev., Nerium oleander L. and Lantana camara L., as well as seedlings of Pelargonium zonale L. were grown in media containing cotton gin trash compost, rice hulls, peat and perlite in various ratios, and their vegetative growth and flowering was determined and compared with a control medium of 1 peat:1perlite (by volume). When up to 60% of peat in the control medium was replaced by cotton gin trash compost plant height was slightly reduced, except in P. zonale, the number of flowers was increased, except in pot D. grandiflora, and flowering was accelerated in all species except N. oleander. When half or all the perlite of the control was replaced by rice hulls, plant height and flower number was similar to that of the control plants, except in pot D. grandiflora where the number of flowers was reduced and in cut D. grandiflora where both stem length and flower number were reduced; also, in L. camara total replacement of perlite by rice hulls gave short...

In Pelargonium, the plastid mutation in three independent cell layers L1, L2, and L3, can produce plastid chimeras with visible shoot colour difference such as GWG (green-white-green) and GGW (green-green-white). Chimera can be used to trace the relationship between the cell layers of different genotypes during shoot development and the effect of the mutated genes on shoot development. In this study, we have obtained different adventitious shoots with GGG, GWG, GGW, and WWW combinations of cell layers through tissue culture of petioles and internodes from GGW and GWG chimeras of Pelargonium zonale `Mrs Pollock'. Much higher percentage (14.9%) of chimeral adventitious shoots was obtained from GGW tissues than from GWG tissues (4.2%). Of the 10.8% chimeral adventitious shoots regenerated in this experiment, 8.6% are different from the original type of explants. This result indicated that cells at least in both L2 and L3 of the explants were involved in the regeneration of the adventitious shoots. The number of shoot types regenerated is likely dependent on the number and the type of cells that were in direct contact with the culture medium. It is suggested that the mixed cells can be used to produce the chimera by tissue culture. Three possible ways to form the chimeras in vitro culture were discussed. Chemical names used: TDZ =1-phenyl-3-(1,2,3-thiadiazol-5-yl)urea (Thidiazuron); IAA = Indole-3-acetic acid; PVP = polyvinylpyrrolidone.

The aim of this study was to establish the possibility of growing Rosa canina L. and Pelargonium zonale L. in tissue culture and suitability of alternative components and their mixtures as a substrate for adaptation of in vitro seedlings of these floral species. In this research, four alternative components (cocoa shell (A), willow bark (B), spent mushroom substrate (C), sawdust (D)) and six of their mixtures were analysed. Klasman Potgrond P (for wild rose) and Balkon – blumenerde (for pelargonium) were analysed as a control substrate. Statistical analysis has revealed significant differences between all the treatments (substrates) and their analysed properties. An average percentage of adapted seedlings in all of the substrates was 54.68% for wild rose, and 99.68% for pelargonium. The largest values of morphological properties for the wild rose were determined on an M2 (30% A + 20% B + 40% C + 10% D) substrate mixture, where the greatest number of shoots, leaf number, fresh overground mass, total fresh mass of seedling and the ratio of fresh and dry overground mass and root were recorded. Chemical composition of wild rose seedlings varied among the treatments, but the highest content of macro and micro elements was determined in the seedlings grown on sawdust (D) and control substrate (E). The largest values of almost all morphological properties of pelargonium were also recorded on substrate mixtures M4 (18% A + 22% B + 40% C + 20% D) and M6 (18% A + 42% B + 20% C + 20% D). Furthermore, while the largest morphological properties of pelargonium seedlings were recorded in the mixtures, the highest content of macro and micro elements determined in the seedlings was on those grown on alternative components, especially in the seedlings grown on a willow bark substrate.

: NH4 + : ratios, N recovery, leachate Abstract. Stock plants of Pelargonium zonale 'Empress' were grown for 130 days on coarse tuff medium in a green- house. Four N concentrations (50, 100,200, and 400 mg N/liter) and three NO 3 - : NH4 + : ratios (70:30, 60:40, and 40:60) were applied. The development of mother plants, production of cuttings, and the recovery of applied N were measured. Number of cuttings was not affected by any treatments except for the low N concentration. The proportion of absorbed N was higher than that of water in the plants treated with 50 or 100 mg N/liter, while those fertilized with 200 or 400 mg N/liter absorbed more water relative to N uptake. Nitrogen recovery efficiency decreased from 70% to 10% for the 50- to 400-mg N/liter treatments, respectively. Percentage of applied N lost by leaching (30% to 70%), and N that could not be accounted for (0.5% to 20%), increased with increasing N concentration and NH 4 + percentage in the solution. The minimum concentration to be used in fertilization of Pelargonium mother plants is 100 mg N/liter. Optimal N supplied ranged between 100 and 200 mg N/liter. The quality of Pelargonium stock plants affects the size or number of cuttings and their root regeneration. Nutrition is one of the factors that has been reported to affect stock plant de- velopment and the production of cuttings (Read, 1987). Nitrogen concentrations affect plant growth and cutting yield (Lemaire, 1983; Lemaire and Dartigues, 1984; Reuther and Rober, 1980). The proportion of NO 3 - or NH 4 +

Two viruses, detected frequently in the Netherlands in pelargonium, were identified by serology and test plant reactions. Antisera were prepared and an ELISA procedure was developed to detect the viruses in pelargonium.

Summary In studies of a parasite-host plant system, 5 pelargonium cultivars were used to test the influence of plant cultivars on concentration of mineral elements in parasite tissue — Cuscuta reflexa (dodder). Experiments were performed in a greenhouse where dodder parasitized different pelargonium cultivars for 60 days. Mineral analysis of all 5 cultivars showed that leaf N concentration was higher than in dodder, while stem concentration of N was lower than in dodder. Concentrations of P and K were higher in dodder tissue than in host plant. Concentrations of Ca and Mg were extremely reduced in dodder.

The objective of this study was to evaluate the effect of the NO3‐/NH4+ ratio in the nutrient solution, combined with seasonal ambient temperature and irradiation level provided to Pelargonium zonale cvs. ‘Empress’ and ‘Rubin’ stock plants, on production and their cuttings’ qualities. Plants were grown for 7 months on tuff:peat medium with three NO3‐/NH4+ ratios, in a greenhouse with high natural irradiance conditions or at reduced irradiance level (30% shading simulated the marginal production season). Cutting production was negatively affected by the low irradiance level and low ambient temperature. The NO3‐/NH4+ ratio did not affect cutting yields in natural and reduced irradiance except for a very high NH4+ proportion (70%) in the solution. Rooting ability and quality were affected reciprocally by the irradiance level, compared with yield. The NO3‐/NH4+ ratio applied in the two irradiance regimes affected the rooting significantly; a low ratio was preferable at low irradiance level and low te...

8 páginas, 2 figuras, 3 tablas, 10 referencias.-- International Symposium on Composting and use of Composted Materials for Horticulture, celebrado del 5-11 de abril 1997, en Ayr, Scotland, United Kingdom., The effects of compost based substrates on growth and nutrition of geranium (Pelargonium zonale cv Lucky Break F2) were investigated. Substrates of manure compost, cotton gin trash compost, municipal solid waste compost and pine bark utilized as potting media for domestic use, produced an underdevelopment of geranium plants with respect to the control. This behaviour is related to the inferior physical properties of the compost-based potting media, nitro gen immobilization due to the high C/N ratio of pine bark, and probably lack of available phosphorus originated by high calcium and high pH of the compost-based media. Nitrogen fertilization and a longer period of cultivation diminished the differences between plants grown in the control and in compost-based media. Plants grown in compost mixtures which were rich in K showed K and Ca leaf contents closer to the optimum range than did control plants., This work was supported by the Agencia de Medio Ambiente of the Junta de Andalucía and by Fertilizantes Orgánicos Melguizo, S. L.

In 2002 the USDA reported potted geraniums accounted for $150 million in wholesale value, more than any other bedding or garden plant surveyed. Despite the importance of the geranium in floriculture production, little published research data is available pertaining to the media pH requirements of zonal and ivy geraniums. Current recommendations suggest zonal geraniums be grown at pH 5.7-6.6 and ivy geraniums at pH 5.0-6.2. The wide range in root medium pH recommendations for both zonal and ivy geraniums and the lack of research data prompted this research. Also, the basis for recommending a lower medium pH for ivy geraniums could not be found in published literature. The research objectives were to investigate the effect of medium pH on plant growth and to determine more precise recommendations for both species. The growth of 3 cultivars each of zonal and ivy geraniums growing in 8 medium pH treatments were evaluated. Limestone and hydrated lime were incorporated at increasing rates into a 1:1:1 peat, perlite and bark mix to achieve a medium pH ranging from pH 4.0-7.5. Plants were harvested at weeks 3, 6, and 11 and plant dry weight and media pH were determined. Leaf luminance, chroma and hue were evaluated at week 10. Plant dry weight was greatest at pH 6.55 or higher for both zonal and ivy geraniums at week 11. Leaves of plants grown at pH 6.55 or higher had significantly lower luminance and chroma and greater hue in all cultivars, corresponding to leaves that were darker, less vivid, and deeper green in color. This study shows a root medium pH greater than pH 6.5 results in greatest plant dry weight accumulation and quality of leaf color for both zonal and ivy geraniums. This study also shows ivy geraniums can be grown at the same media pH as zonal geraniums.

Pelargonium species comprise one of the most popular groups of flowering potted plants in the world (Wood 1966). Most cultivated Pelargonium plants are grown for their colorful showy flowers, others for their scented foliage and exotic leaf shapes. The genus Pelargonium contains approximately 300 species, most of which are native to South Africa (Moore 1971). Pelargonium zonale was first introduced into Europe in 1609 (Ewart 1980). Currently, P. x hortorum L.H. Bailey (garden geranium), P. x domesticum L.H. Bailey (regal geranium), and P. peltatum (ivy geranium) are the most economically important Pelargonium species. Records of the crosses that produced the hybrid species were not kept. Pelargonium x hortorum is thought to have originated from four wild species: P. zonale, P. inquinans, P. frutetorum, and P. scandens. Pelargonium x domesticum is thought to have originated from seven wild species: P. angulosum, P. betulinum, P. capitatum, P. cordifolium, P. cucullatum, P.fulgidum, and P. grandiflorum (Ewart 1980).

A recent survey of symptomless ornamental geraniums ( Pelargonium zonale , P. peltatum and P. grandiflorum ) in Spain (2000–2003) revealed viral infections in 52·4% of the tested plants (Alonso & Borja, 2005). Most infected plants contained tombus-like viruses such as Pelargonium line pattern virus (PLPV), either alone or in combination with other viral pathogens. Several little-studied PLPV-related viruses have been reported in Pelargonium spp. but their distribution and importance to geranium growers is unknown since they are not usually included in phytosanitary programmes. One of these viruses, Pelargonium chlorotic ring pattern virus (PCRPV), was recently sequenced (GenBank Acc. No. AY038069) and found to be related to PLPV in nucleotide sequence and genome organization (Kinard & Jordan, 2002; Castano & Hernandez, 2005). To assess the occurrence of PCRPV in Spain 5 samples from the previous survey and 3 gathered in 2006 were tested. Total RNA was extracted using Plant RNA Reagent (Invitrogen) and reverse transcribed with Superscript II-RT (Invitrogen) and primer CH149 (5 ′ -CCGATTCTCGAGCTGCCAATC-3 ′ ), complementary to positions 1543–1523 of PCRPV. PCR used primers CH149 and CH148 (5 ′ -CGGTTTGAGCACTCTGCGTATC-3 ′ ), homologous to positions 1277–1298 of PCRPV. An amplicon of the expected size (267 bp comprising a region of the viral polymerase gene) was generated in five samples from different geographical origins (Zaragoza, Zamora, Aranjuez and Cordoba) and collecting times (2000, 2003 and 2006). The amplicons derived from two separate samples were sequenced (GenBank Acc. Nos. EF635383 and EF635384) and showed 95% nucleotide and 99–100% amino acid sequence identity with the PCRPV reference sequence. An Italian isolate of PCRPV was recovered from P. zonale with vein banding and leaf distortion (Lisa et al ., 1996; Kinard & Jordan, 2002); however from our results, PCRPV infection can also be asymptomatic. This is the first report of PCRPV in Spain.