Population modelling of Gelidium sesquipedale (Rhodophyta, Gelidiales)

A matrix population model of Gelidium sesquipedale, a commercial agarophyte from the Northeast Atlantic, was developed based on demographic data obtained during two years in a commercial stand of Cape Espichel, Portugal. G. sesquipedale individuals were classified into categories such as life cycle phase, spores, juveniles and adult frond size, because the species vital rates, fecundity, fertility, survival, growth and breakage depend on them. We also exemplify the use of a user-friendly modelling software, Stella, to develop a structured-population model. This is the first time this software has been used to model the demography of seaweed populations. The Stella model developed here behaved very similarly to the matrix model, because of its particular construction, which causes the forcing functions to be discrete rather than continuous. The relative importance of spore recruitment and vegetative growth of new fronds in both population growth and population structure was investigated. Elasticity analysis suggests that vegetative recruitment is the most important demographic parameter controlling population growth together with survival and transitions between juveniles (1–6 cm fronds) and class 1 fronds (6–9 cm fronds). On the other hand, sexual reproduction may, by itself, efficiently control the relative proportion of gametophytes and tetrasporophytes in the population, even though its contribution to recruitment is extremely small. A 40% difference in the growth rates of gametophyte and tetrasporophyte submatrices resulted from natural differences in spore recruitment rates. This revised version was published online in June 2006 with corrections to the Cover Date.     

Light response curves for Gelidium sesquipedale from different depths, determined by two methods: O2 evolution and chlorophyll fluorescence

Photosynthesis-light response curves of Gelidium sesquipedale from the west coast of Portugal (Cape Espichel) were determined at four different depths, 3, 10, 15 and 22 m. Data acquisition using chlorophyll a fluorescence methodology and oxygen electrode measurements were compared. Response curves were determined over an increasing range of irradiance values (I), from darkness to 900 μmol photon m-2 s-1 PAR. In general, light response curves obtained for G. sesquipedale showed a similar pattern whether determined by the chlorophyll fluorescence method or by oxygen evolution. The photosynthetic capacity of G. sesquipedale decreased with depth, as expected, revealing a ‘sun’ and ‘shade’ acclimation pattern, between shallow and deeper waters. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effects of solar UV stress on chlorophyll fluorescence kinetics of intertidal macroalgae from southern Spain: a case study in Gelidium species

Photoinhibition and recovery kinetics after short exposure to solar radiation following three different irradiance treatments of irradiances (PAR, PAR+UVA and PAR+UVA+UVB) was assessed in two intertidal species of the genus Gelidium, Gelidium sesquipedale and G. latifolium, collected from Tarifa (southern Spain) using in vivo chlorophyll fluorescence (PAM fluorometry). After 3 h UV radiation exposure, optimal quantum efficiency (Fv/Fm) in G. sesquipedale decreased between 25 and 35% relative to the control. Under PAR alone, values decreased to 60%. In G. latifolium, photoinhibition did not exceed 40%. Similar results were found for the effective quantum yield (ΔF/Fm′), however, no marked differences in relation to light treatments were seen. When plants were shaded for recovery from stress, only in G. latifolium a significant increase in photosynthesis was observed (between 80 and 100% of control). In contrast, photosynthesis of G. sesquipedale suffered a chronic photoinhibition or photodamage under the three light irradiances. Full solar radiation (PAR+UVA+UVB) affected also the electron transport rate in both species. Here, initial slopes of electron transport vs. irradiance curves decreased up to 60% of controls. Although the recovery kinetic under PAR+UVA+UVB conditions was delayed in G. latifolium, after 24 h recovery this species reached significantly higher than G. sesquipedale. PAR impaired electron trasport only in G. sesquipedale. Overall, both species are characterized by different capacity to tolerate enhanced solar radiation. G. latifolium is a sun adapted plant, well suited to intertidal light conditions, whereas G. sesquipedale, growing at shaded sites in the intertidal zone, is more vulnerable to enhanced UV radiation. This revised version was published online in June 2006 with corrections to the Cover Date.     

Marine plant harvest in Portugal

This work brings together the scattered information on marine plant harvests and the colloid extraction industry in Portugal, as an initial contribution to the improvement of resource management. The first phase of exploitation of marine plant resources started prior to the 14th century, with the gathering and sale of storm-tossed seaweeds for fertilizer. The harvest of seagrasses and algae at Ria de Aveiro was of great economic importance. The second phase of resource exploitation began with the wider scale harvest of agarophyte species for colloid extraction. Portugal is at present the third largest harvester of the agarophytes Gelidium and Pterocladia (2500 t annually), and it is the fifth largest agar producer (350 t annually). Other colloid-producing species, including Chondrus crispus and Mastocarpus stellatus, are also harvested for export. The total agarophyte landings, agar production and income from agar exports is far below the maximum levels attained in the early 1970s. The status of stocks in each different harvest zone on the continental coast and the Azores is examined. Although there is an effective management structure for the Portuguese marine plant resource, research is needed to provide a sound biological basis for management. author for correspondence     

NUCLEOTIDE SEQUENCES OF SMALL-SUBUNIT AND INTERNAL TRANSCRIBED SPACER REGIONS OF NUCLEAR rRNA GENES SUPPORT THE AUTONOMY OF SOME GENERA OF THE GELIDIALES (RHODOPHYTA)

The lack of homogeneity in all previously proposed, distinguishing characteristics has left the relationships of taxa within the Gelidiales as one of the most enduring taxonomic uncertainties in the Rhodophyta. Although a precise knowledge of the taxonomy of commercially harvested members of the Gelidiales would assist resource management, agronomic practices, and marketing, even the distinction between two major groups, Gelidium and Pterocladia, has long remained controversial. In this study, the 18S ribosomal RNA (rRNA), internal transcribed spacer 1 (ITS1), 5.8S rRNA, and ITS2 regions of Gelidium latifolium (Greville) Bornet et Thuret, G. sesquipedale (Clemente) Thuret in Bornet et Thuret, G. vagum Okamura, Pterocladia lucida (Brown ex Turner) J. Agardh, and a recent segregate from Pterocladia, Pterocladiella capillacea (Gmelin) Santelices et Hommersand, were sequenced and analyzed. The ITS1, 5.8S rRNA, and ITS2 regions of G. arbuscula (Montagne) B=orgesen, G. canariensis (Grunow) Seoane-Camba, G. capense (Gmelin) Silva, and G. pristoides (Turner) Kützing were also sequenced. Phylogenetic analyses based on the 18S rRNA genes from four Gelidium species, Pterocladia lucida, and Pterocladiella capillacea , compared with 18S rRNA genes from several other red algae confirmed the division between Gelidium and the Pterocladia/Pterocladiella isolates and were consistent with the recently proposed segregation of Pterocladiella from Pterocladia. Analyses based on the ITS regions of seven Gelidium species, Pterocladia lucida, and Pterocladiella capillacea were completely consistent with the conclusions drawn from the 18S rRNA data. There were extensive length and sequence differences between Gelidium and Pterocladia/Pterocladiella . In addition, there were larger sequence differences between Pterocladiella and Pterocladia than exist among Gelidium isolates, in keeping with the recently proposed separation of the former two taxa.     

Genetic diversity of the great bustard in Iberia and Morocco: risks from current population fragmentation

We studied the genetic diversity of great bustards (Otis tarda) in Iberia and Morocco, the main stronghold of this globally endangered species. Samples were collected from 327 individuals covering most of the distribution range within the study area. Sequence variation in a 657 bp fragment of the mtDNA control region revealed 20 variable sites defining 22 haplotypes, two of them exclusive to Morocco. Genetic diversity showed marked regional differences (π = 0–0.53, h = 0–0.89). Multidimensional scaling analysis based on F _ST values showed a clear division between Morocco and the Iberian Peninsula, with no evidence of current gene flow between them. Our results suggest that Morocco, where few matrilines have persisted to present, was colonized from Iberia thousands of years ago. Last century reports suggest dispersal through Gibraltar, when the species was more abundant at both sides of the Strait but later population declines and the Strait’s barrier effect have favoured current genetic isolation. Within Iberia, only the most peripheral populations (Navarra, Aragón and Andalusia) differed significantly from the main ones in central Spain. The first two showed extremely low genetic diversity and are probably threatened by inbreeding depression. Diversity was higher in Andalusia, where three exclusive haplotypes were found, suggesting some degree of isolation from other populations. Andalusia and Morocco could be regarded as separate management units which hold a significant proportion of the current genetic diversity and thus deserve urgent conservation measures.     

Response of the tropical red seaweed Gracilaria cornea to temperature, salinity and irradiance

The agarophyte Gracilaria cornea, collected over 2.5 y in the Florida Keys, shows adaptations to oceanic salinities and subtropical to tropical water temperatures in its photosynthetic and respiratory responses as measured with a respirometer. No seasonal pattern in responses to irradiance, temperature, and salinity were evident between five collections over a 20-month period, indicating the tropical nature of the populations from Bahia Honda and Pigeon Keys. Concentrations of chlorophyll a (0.09 to 0.41 mg g d wt-1) and phycoerythrin (0.06 to 0.36 mg g d wt- 1) were low and reflect the low nutrient regime of the habitats, especially when compared to laboratory cultured plants. Compensation and saturation irradiances were also low (11–38 and 90–127 μmol photon m-2 s-1), indicating acclimation to lower irradiances in their shallow (1–2 m depth) habitats where turbidity can be high. In comparison with other subtropical and warm temperate species of Gracilaria, G. cornea had lower levels of pigment, but similarly high photosynthetic efficiency, demonstrating shade adaptation; it had only limited tolerance to salinities below 20‰ and temperatures below 15 °C. Thus, G. cornea from the Florida Keys in mariculture would require subtropical to tropical temperatures and stable oceanic salinities. This revised version was published online in June 2006 with corrections to the Cover Date.     

Validity of the gerreid fish,Gerres macracanthus Bleeker, 1854, with designation of a lectotype,and designation of a neotype forG. filamentosus Cuvier, 1829

Gerres macracanthus Bleeker, 1854, for many years having been explicitly or tentatively synonymized withG. filamentosus Cuvier, 1829, is redescribed as a valid species.Gerres macracanthus differs fromG. filamentosus in lacking vertical rows of dark ovoid spots on the body, having instead only indistinct vertical bands in both subadult and adult stages, in addition to shorter second and third anal fin spines (9.1–13.9% and 10.4–14.4% of standard length [SL] vs. 12.3–19.6% and 11.9–17.3% of SL), fewer ored lateral line scales (41–44 vs. 43–46) and fewer scales between the base of the 5th dorsal fin spine and the lateral line (4–5 vs. 4 1/2–5 1/2), and above and below the lateral line (5 1/2–6 1/2/9 1/2–10 1/2 vs. 6 1/2–7 1/2/10 1/2–11 1/2). AlthoughG. filamentosus has similarly, indistinct vertical bands on the body up to ca. 100 mm SL, specimens over ca. 100 mm SL develop diffuse ovoid spots in each vertical band. Furthermore,G. macracanthus is generally a smaller species, apparently attaining a maximum size of ca. 170 mm SL, compared with ca. 250 mm SL forG. filamentosus. Formerly known from the Philippines, Indonesia, New guinea, India and the Arabian Gulf,G. macracanthus is newly-recorded from Japan, China, the Gulf of Thailand, the Red Sea and South Africa. A lectotype and three paralectotypes are designated forG. macracanthus Bleeker, 1854, in addition to a neotype forG. filamentosus Cuvier, 1829.     

DNA EXTRACTION AND RAPD MARKERS TO ASSESS THE GENETIC SIMILARITY AMONG GELIDIUM SESQUIPEDALE (RHODOPHYTA) POPULATIONS1

A simple method developed for genomic DNA isolation from fungus was tested on the red alga, Gelidium sesquipedale (Clem.) Born et Thur., which is commercially exploited for its high sulfated polysaccharide (agar) content. This method is faster, cheaper, and less toxic than conventional phenol/chloroform methods. Random amplified polymorphic DNA (RAPD) amplifications were performed successfully without the necessity of purifying the DNA. RAPD markers were used to investigate the genetic similarity among three natural populations of G. sesquipedale from southern Portugal. Bulked-genomic DNA samples of 15 different individuals were made in each population. These can be conceived of as a sample of the population DNA. Of the 62 primers screened, 41 produced bands and 22 revealed polymorphisms. Genetic similarities among populations were high. Populations that are further away from each other have the lowest similarity coefficients, whereas the intermediate Ingrina population, located on the south coast, showed higher genetic similarity with the Odeceixe population located on the southwest coast, than with the São Rafael southern population. This suggests a higher genetic flow between Odeceixe and Ingrina or the result may be a founder effect in the sense that the species has propagated from the east coast to the south coast of Portugal. We conclude that the use of this isolation method with RAPD analysis is appropriate to characterize the genetic variability of this commercial species along its geographical distribution. Large sample sizes can be screened at a relatively low cost. Finding genetic markers for commercial populations of G. sesquipedale may be of industrial interest.     

Physiological responses of Pterocladia and Gelidium (Gelidiales,Rhodophyta) from the Azores,Portugal

Manometric studies were conducted on Pterocladia capillacea, Gelidium latifolium and Gelidium spinulosum from the Azores, Portugal to determine optimal values of temperature, light and salinity for growth. Physiological responses were considered in relation to vertical distribution patterns of these species commonly observed throughout the Azores. Optimal parameters for the growth of Pterocladia capillacea, Gelidium latifolium and G. spinulosum were 17 to 25 °C, a photon flux density between 200 and 300 µmol m^–2 s^–1 and salinities of 25 to 35.     

Behavioural Flexibility and Numerous Potential Sources of Introduction for the Sacred Ibis: Causes of Concern in Western Europe?

In order to examine the dynamics and potential impact of the recently introduced sacred ibis Threskiornis aethiopicus, we review the published and unpublished data and report new information on its distribution in West European countries and particularly in France. This species, which escaped from zoos during the 1990s, is well established and has spread on the Atlantic coast and in Mediterranean region of France, with a mid-winter population reaching ca. 3200 individuals in winter 2004–2005 and ca. 1100 breeding pairs in spring 2005. The species has also escaped from zoological parks in Belgium, Germany, Spain, Italy and Portugal, and feral populations are established in Piedmont (Italy) and in the Canary Islands (Spain). The species dispersing ability has led to observations over hundreds of kilometres from the established colonies. We identify that in temperate habitats the sacred ibis shows a behavioural flexibility similar to that known in its tropical native range, including a large diet spectrum (insects, molluscs, refuse, bird eggs, etc.) and an ability to use various habitats (meadows, rubbish dumps, marshes, reedbeds, seashore, ploughed fields, etc.). This plasticity, the fact that predation by ibises is observed on nests of threatened bird species, and the number of potential sources of ibis in Europe (zoos) are causes of concern suggesting that precautionary measures should be taken to prevent the spread of this new alien species.     

BRYOZOANS INCREASE AVAILABLE CO2 FOR PHOTOSYNTHESIS IN GELIDIUM SESQUIPEDALE (RHODOPHYCEAE)

A possible benefit of the presence of the epiphytic bryozoan Electra pilosa (L.) for the red macroalga Gelidium sesquipedale (Clem.) Thuret et Bornet is described. Absorption spectra and photosynthetic parameters of O₂ evolution vs. irradiance curves were determined for both epiphytized and nonepiphytized thalli. The absorptance of G. sesquipedale thalli for PAR was not modified by the presence of the epiphyte. Gross photosynthetic rates at saturating light were approximately doubled in epiphytized thalli. Photosynthesis by G. sesquipedale was enhanced when CO₂ concentration was increased in the medium by a decrease in pH. On the other hand, an increase in pH from 8.1 to 8.7 produced a significant reduction of the O₂ evolution rates indicating that G. sesquipedale has a very low capacity to use HCO₃⁻. The decrease in photosynthesis at high pH was higher in nonepiphytized thalli than in epiphytized ones, suggesting that the amount of available CO₂ is higher in the presence of E. pilosa. This positive effect was attributed to the CO₂ released by respiration of the epiphyte.     

Cyclic AMP levels in several macroalgae and their relation to light quantity and quality

Total cAMP levels were measured in the macroalgae Dictyota dichotoma, Gelidium sesquipedale and Ulva rigida under different light conditions in order to study its regulation either by phytochrome or photosynthesis. Incubation in red or far-red light did not promote a phytochrome-like response; instead, it showed a synergistic effect upon cAMP accumulation. cAMP levels seemed to depend on the amount of energy applied. The correlation between photosynthetic oxygen evolution and cAMP variations at sub-saturating white light irradiance pointed to photosynthetic electron transport as involved in the regulation of cAMP accumulation at least in G. sesquipedale and U. rigida. Inhibitors of thylakoidal and mitochondrial electron transport chains reduced cAMP levels in 70 to 99%. We conclude that cAMP accumulation could be regulated by photosynthetic activity rather than phytochrome in the macroalgae studied.     

A NEW AGAROPHYTE SPECIES,GELIDIUM EUCORNEUM SP. NOV. (GELIDIALES,RHODOPHYTA), BASED ON MOLECULAR AND MORPHOLOGICAL DATA1

Gelidium is an economically and ecologically important agar‐producing genus. Although the taxonomy of Gelidium has been the focus of many published studies, there is still a need to reevaluate species‐level diversity. Herein, we describe Gelidium eucorneum sp. nov. based on specimens collected off Geojedo on the southern coast of Korea. G. eucorneum is distinguished by cartilaginous thalli with brush‐like haptera, rhizoidal filaments concentrated in the medulla, and globose cytocarps that are horned with multiple determinate branchlets. The species occurs in wave‐exposed intertidal sites, sometimes in association with other mat‐forming algae. Phylogenetic analyses (rbcL, psaA, and cox1) reveal that G. eucorneum is unique and clearly distinct from other species of the genus. The clade containing Gelidium vagum and Acanthopeltis longiramulosa was resolved as a sister group to G. eucorneum. We suggest that the diverse morphologies of G. eucorneum, G. vagum, and Acanthopeltis developed from a common ancestor in East Asian waters. This study shows that even in well‐studied areas, more agarophyte species are to be added to the world inventory of red algae.     

Multiple genetic divergences and population expansions of a Mediterranean sandfly,Phlebotomus ariasi,in Europe during the Pleistocene glacial cycles

Phlebotomus ariasi is one of the two sandflies transmitting the causative agent of zoonotic leishmaniasis, Leishmania infantum, in France and Iberia, and provides a rare case study of the postglacial re-colonization of France by a Mediterranean species. Four DNA sequences were analysed—mitochondrial cytochrome b (cyt b), nuclear elongation factor-1α (EF-1α) and two anonymous nuclear loci—for 14–15 French populations and single populations from northeast Spain, northwest Spain, Portugal and Morocco. The presence of cryptic sibling species was not revealed by phylogenetic analyses and testing for reproductive isolation between sympatric populations defined by the two most divergent cyt b haplogroups. No locus was shown to be under positive directional or balancing selection and, therefore, molecular variation was explained demographically. Each nuclear locus showed shallow isolation by distance from Portugal to the French Pyrenees, but for both cyt b and EF-1α there was then a step change to the upland Massif Central, where leading-edge populations showed low diversity at all loci. Multiple genetic divergences and population expansions were detected by analyses of cyt b and dated to the Pleistocene. Endemicity of one cyt b sub-lineage suggested the presence of a refuge north of the Pyrenees during the last glacial period. Monopolization of the Massif Central by genetically differentiated populations of P. ariasi might possibly hinder the northwards spread of leishmaniasis.     

Impacts of climate warming on the long-term dynamics of key fish species in 24 European lakes

Fish play a key role in the trophic dynamics of lakes. With climate warming, complex changes in fish assemblage structure may be expected owing to direct effects of temperature and indirect effects operating through eutrophication, water level changes, stratification and salinisation. We reviewed published and new long-term (10–100 years) fish data series from 24 European lakes (area: 0.04–5,648 km²; mean depth: 1–177 m; a north–south gradient from Sweden to Spain). Along with an annual temperature increase of about 0.15–0.3°C per decade profound changes have occurred in either fish assemblage composition, body size and/or age structure during recent decades and a shift towards higher dominance of eurythermal species. These shifts have occurred despite a reduction in nutrient loading in many of the lakes that should have benefited the larger-sized individuals and the fish species typically inhabiting cold-water, low-nutrient lakes. The cold-stenothermic Arctic charr has been particularly affected and its abundance has decreased in the majority of the lakes where its presence was recorded. The harvest of cool-stenothermal brown trout has decreased substantially in two southern lakes. Vendace, whitefish and smelt show a different response depending on lake depth and latitude. Perch has apparently been stimulated in the north, with stronger year classes in warm years, but its abundance has declined in the southern Lake Maggiore, Italy. Where introduced, roach seems to take advantage of the higher temperature after years of low population densities. Eurythermal species such as common bream, pike–perch and/or shad are apparently on the increase in several of the lakes. The response of fish to the warming has been surprisingly strong and fast in recent decades, making them ideal sentinels for detecting and documenting climate-induced modifications of freshwater ecosystems.     

A study of the phycocolloids from Gelidium madagascariense and Eucheuma denticulatum (Rhodophyta) collected on the south coasts of Madagascar

Several species of red algae known to contain agar or carrageenan are abundant on the southeast and southwest coasts of Madagascar. The agarophyte Gelidium madagascariense, collected in the Fort Dauphin area, has been exported on a small scale to Japan for several years. FT-IR and GLC analysis show that it contains an agar polymer, of which the methylated fraction contains predominantly 6-O-methyl galactose and traces of 4-O-methyl galactose. Eucheuma denticulatum grows profusely on the coral reefs in the Tulear area. FT-IR and GLC analysis show that it contains iota-carrageenan, with no methyl-derivative contaminants. The 3,6-anhydro-galactose content was found to be rather low, suggesting a possible contamination with deviant iota. The economic potential of other sources of phycocolloids, as well as the possibility of farming different species of Eucheuma in the Tulear area, is discussed.     

Cytisus purgans auct(Leguminosae-Papilionoideae comprises four distinct species)

Based on a study of the morphology and stem anatomy of a broad sample of specimens attributed to Cytisus purgans auct. non Cytisus purgans (L.) Boiss. four species are recognized. Two species are non-spiny: Cytisus oromediterraneus Rivas Martínez et at. is a widely distributed taxon ranging from central France to north-central Spain and Portugal, and C. galianoi Talavera & Gibbs, sp. nov., which is restricted to schistose sierras in south-east Spain. C. oromediterraneus has 8-ribbed stems and 2-ribbed stipular organs, whilst C. galianoi has 10-ribbed stems and 3-ribbed stipular organs. Of two spiny species, Cytisus balansae (Boiss.) Ball wkh 10-ribbed stems, occurs in calcareous mountain areas, 1800–2500 m in Algeria and southern Morocco, whilst C. valdesii Talavera & Gibbs, nom. nov. with 13-ribbed stems, occurs in die High and Middle Atlas of Morocco. Both north African species have 3-ribbed stipular organs.     

Effects of temperature and salinity on the growth of Gracilaria verrucosa and G. chorda, with the Potential for mariculture in Korea

Effects of temperature and salinity on the growth of the two agarophytes, Gracilaria verrucosa (Hudson) Papenfuss and Gracilaria chorda Holmes were examined in Korea. Both species grew over a wide range of temperatures (10–30 ^∘C) and salinities (5–35‰), and grew well at 17–30 ^∘C and a salinity of 15–30‰. In culture, G. verrucosa grew faster than G. chorda and their maximum growth rates were 4.95% day⁻¹ (30 ^∘C, 25‰) and 4.47% day⁻¹ (at 25 ^∘C, 25‰), respectively. In the field population the maximum growth and fertility of G. chorda were observed in summer. The growth rate of G. verrucosa was slightly higher than that of G. chorda for 2 weeks on the cultivation rope and in culture but it was much lower after being contaminated with epiphytes. The biomass of the epiphytes was 0.82 g dry wt. per host plant in G. verrucosa and 0.001 g in G. chorda. G. chorda exhibited resistance to epiphytism and grew 7 times in length and the dry weight increased 15 times after 55 days. In conclusion, G. chorda appears to be a good agarophyte with a fast growth rate and resistance to epiphytesm, and compared with G. verrucosa, has good potential for commercial cultivation.     

Effect of seaweed concentrate on hydroponically grown spring barley

Spring barley (Hordeum vulgare cv. Triumph) was grown hydroponically over a 6-week period. Two treatments were incorporated either into the hydroponic solution or sprayed onto the plants at rates of 1 ml per 3 litres. The treatments applied were: (i) a seaweed concentrate prepared fromAscophyllum nodosum (L.) Le Jolis (marketed as Maxicrop Triple), (ii) a ‘Trace element’ treatment incorporating the micro and macro nutrients added to the seaweed extract base to produce the formulated product Maxicrop Triple and (iii) a control treatment. Irrespective of the mode of application, plants treated with Maxicrop Triple grew faster than plants under either of the two other treatments. Elevated growth rates were also found for the ‘Trace element’ treated plants when incorporated into the hydroponic solution. At the final harvest, plants with Maxicrop Triple incorporated into the hydroponic solution showed increases from 56–63% over the control treatment for the growth characteristics measured. ‘Trace element’-treated plants produced increases of between 25–45%. When the treatments were sprayed the effect was less pronounced. Maxicrop Triple increased growth characters by 35–38% and the ‘trace element’ treatment gave increases in the range of 2–13%.