Bark Substrate Research Articles

Micronutrient Availability from Steel Slag Amendment in Pine Bark Substrates

Steel slag is a byproduct of the steel industry that can be used as a liming agent, but also has a high mineral nutrient content. While micronutrients are present in steel slag, it is not known if the mineral form of the micronutrients would render them available for plant uptake. The objective of this research was to determine if steel slag could be used as the sole micronutrient source for container-grown nursery crops. Butterfly bush (Buddleja davidii ‘Pink Delight’) and rose (Rosa ‘Radrazz’) were grown in #3 (3 gal) containers in a base substrate composed of pine bark and peatmoss (80:20, by vol). The base substrate was amended with the following treatments: with a complete controlled release fertilizer (CRF) including micronutrients (C-control), a substrate amended with a different CRF containing only N, P, and K along with a granular micronutrient package (M-control), and three additional treatments amended with the CRF (N, P, and K only) and either 1.2, 2.4, or 4.8 kg·m−3 (2, 4, and 8 lb·yd−3) of steel slag. Plants were harvested at 2 and 4 months after potting (MAP). None of the plants displayed any sign of nutrient deficiency or toxicity throughout the experiment. However, plants grown in the substrate amended with the highest slag rate [4.8 kg·m−3 (8 lb·yd−3)] had lower shoot dry weight (SDW) than both control groups. Substrate pH increased with increasing slag rate, which may have affected micronutrient availability in those substrates. Among the micronutrients analyzed, only Copper (Cu) was consistently deficient in both the substrate and foliar tissue of slag-amended treatments. Steel slag either does not provide a sufficient quantity of Cu or the concomitant increase in pH with increasing rates of steel slag renders Cu unavailable for plant uptake. Steel slag should not be used as the sole source of micronutrients for shrubs grown in pine bark-based substrates.

Use of the evaporative method for determination of soilless substrate moisture characteristic curves

Historically, substrate science has utilized the pressure extraction method to measure soilless substrate moisture characteristic curves, albeit with published discrepancies. Recently, a device utilizing the evaporative method to generate moisture characteristic curves by measuring water potential as volumetric water content decreases via evaporation, known as a Hyprop, has become available. This research compares and contrasts moisture characteristic curves developed over a 2-week period using both the pressure extraction and the evaporative methods for two-component greenhouse (Sphagnum peat and perlite) and nursery (aged pine bark and sand) soilless substrates. The pressure extraction method was conducted between water potentials of 0 and −300hPa (10 data points used in conventional methodology for allotted time), while the evaporative method measurements continued until the tensiometers cavitated (≈ −500 to −700hPa) and provided higher data density (100 data points) within the two week period. The evaporative method was found to produce repeatable results, with subsequent measurements of each substrate providing analogous measurements (P>0.9000 and P>0.3700 for the peat and bark substrate, respectively). There was little variation between the two methodologies for the peat substrate (0.004% difference in the area under the curves from 0 to −300hPa). However, differences were observed between the methodologies for the bark substrate, with the percentage difference increasing with increasing water potential (9.6% at −100hPa; 23.7% at −300hPa). Additionally, the evaporative method measured a continued decrease in volumetric water content of the aged pine bark and sand substrate with increasing water potentials throughout the range of measurements, unlike the pressure extraction method, which has documented issues with loss of hydraulic connectivity between the sample and the plate in coarse highly porous organic substrates. Therefore, the pressure extraction method ceases to decrease in volumetric water content (≤ −65hPa) resulting in a divergence in curves generated by the two methods. Both methods were found to have limitations while measuring substrate water content near saturation, with the pressure plate resistance to free drainage of water influencing measurements and the evaporative method continually underestimating the saturation point. As a result, both methods provided decreased volumetric water content measurements near saturation than when static physical properties were directly measured; therefore, moisture characteristic curves should be used collectively with static properties to correct for underestimation of total porosity and to better yield an understanding of the hydrophysical properties of a soilless substrate.

GERMINATION EFFECT OF DIFFERENT SUBSTRATES ON GRUMIXAMA SEEDS

Grumixama belongs to the Myrtaceae family, members of which have simple leaves, which are generally leaf-opposed, with whole margins, an evergreen color. The Myrtaceae family includes about 140 genera and over 3,000 species. Grumixama is rarely cultivated and its production is normally used in the manufacture of bulk candy, syrup, liqueurs and jams. Because it is rarely cultivated there is virtually no agronomic information about the cultivation of this fruit tree, in particular relating to seedling production and seed germination. The objective of this study was to evaluate grumixama seed germination in two substrates; Tecnomax® (based on pine bark) and washed sand. Sowing was performed in 110 cm3 volume, high-density polyethylene tubes filled with the respective substrates. Sixty days after sowing the germination percentage was evaluated. The height, stem diameter and number of leaves were evaluated at 120 days, when the seedlings had an average height of 10 cm. The pine bark substrate provided the best germination and development of quality grumixama seedlings compared to the washed sand.

Highly compatible Epa-01 strain promotes seed germination and protocorm development of Papilionanthe teres (Orchidaceae)

Symbiotic seed germination serves as a preferred method for orchid multiplication related to conservation and reintroduction programs, which involves isolation, identification, and germination-enhancing testing of symbiotic fungi. This study uses seeds of Papilionanthe teres, a locally endangered and medicinally valuable epiphytic orchid, to attract germination-enhancing fungi on its four host plants. Only one common and highly compatible fungus (Epa-01 strain, Epulorhiza sp.), isolated from seed baiting near three host plants (Averrhoa carambola, Lagerstroemia villosa, Callistemon rigidus), enhanced seed germination by more than 80 % and promoted protocorm development to reach stage 5 (with two leaves). Seeds cocultured with the Epa-01 strain and oat meal agar medium significantly outperformed in germination and growth speed compared with those cocultured with asymbiotic germination medium only, indicating that symbiotic seed germination is an effective method for P. teres seedling production. Bark substrate types have profound effects on symbiotic seed germination and protocorm development possibly due to different abundance and growth vitality of the Epa-01 strain on the four host plants. A significant difference was found in the developmental speed of symbiotic seeds between A. carambola and the other three host plants under ex situ and ex vitro seed germination treatments (all P < 0.05). The results suggest that in situ seed baiting may be used to effectively capture germination-enhancing fungi in epiphytic orchids, and testing the effects of bark substrate types on seed germination and protocorm development contributes to selecting appropriate host plants for its reintroduction into natural habitats.

Využití odpadních materiálů v pěstebních substrátech

Gardeners' practical experience and experimental work prove the affirmation that the used substrate is a very important base for the production of quality nursery products. It is important to emphasis the complexity and synergy of all factors influencing the ecosystem and there mutual relations. Physical, chemical and biological properties do not separately affect the growth and development of plants. In addition, the relations are not statical but differ in relation with other factors changes. This article is dealing with the possibility to use waste material from timber processing in cultivation substrates. The large scale use of such substrates would enable people to reach a relative independence from peat substrates, of which the global reserve is gradually decreasing.Our research activities focus on the use of bark. The basic problems of a bark substrate are easy dehydration and unbalanced nutrition of trees and shrubs. The suggested and experimented cultivation technology solves these problems. It is based on the cultivation of woody species in bark substrates, using modern irrigation systems, slow release fertilisers (Silvamix Forte) and special soil conditioners (TerraCottem). This technology was tested on the following species of trees and shrubs:MalusandBuxus.

Beetles (Coleoptera) of Peru: A Survey of the Families. Nitidulidae

Diversity in Peru: 4 subfamilies, 22 genera, 63 species. Recognition: This family may be recognized by the following combination of adult characters: maxilla lacking galea; antennae typically 11-segmented, with terminal three antennomeres forming a club; antennal insertions moderately to broadly separated; subocular antennal grooves on ventral surface of head present; procoxae transverse with exposed trochantins; prosternum transverse with intercoxal process extending between procoxal cavities, procoxae always separated; mesoventral procoxal rests present; typically five visible abdominal ventrites present; metendosternite stalk present; metasternum with discrimen present; and tarsal formula 5-5-5. Habitat: Several recent comprehensive reviews of Nitidulidae biology are available (Jelinek et al., 2010; Cline, 2005; Audisio et al., 2000; Audisio, 1993). Overall, nitidulid beetles exhibit a diverse set of life history strategies, including: fungivory, saprophagy, phytophagy, pollination activities, facultative predation, necrophagy, frugivory, and inquilinism with social insects. Nitidulids may be collected using a variety of directed (sweeping and beating vegetation/inflorescences, sifting leaf litter, searching under bark and various fungal substrates, as well as in nests of social Hymenoptera) and passive techniques (flight intercept traps, pitfall traps, malaise traps, and mercury vapor or black lights at night). Large numbers of nitidulids can typically be found in palm inflorescences (e.g., Mytrops and related genera); baited fruit or molasses traps (Carpophilus, Colopterus, Brachypeplus, Amphicrossus, Lobiopa, and Cryptarcha), and sifting leaf litter (Stelidota). Notes: Nitidulidae have long been confused with numerous other families of Cucujoidea. In particular, members of Cybocephalidae, Kateretidae, Monotomidae, Cryptophagidae, Biphyllidae, Smicripidae, and Erotylidae have been attributed to Nitidulidae. Recent and upcoming work on the New World Kateretidae (Cline and Audisio, 2010, and unpubl. data) will help improve the diagnostic capabilities for Nitidulidae. A recent treatment of Nitidulidae higher level phylogenetics formally elevated Cybocephalidae to family status and provided an extensive list of adult and larval characters to differentiate this group from Nitidulidae (Cline et al., 2014). Invasive species such as Urophorus humeralis (F.), Epuraea luteola Erichson, and Carpophilus hemipterus (L.) likely occur in the country as they have been transported around the world in various agricultural commodities, in conjunction with several other alien species more or less recently introduced into Peru (Carrasco, 1986; Leschen and Marris, 2005; EPPO, 2010). However, there are no existing records for

The lichen Parmelia physodes (L.) Ach. as indicator for determination of the degree of atmospheric air pollution in the area contaminated by flourine and sulphur dioxide emission

On the area involved in the influence of conteminations emitted by the aluminium works and electric power plant, the degree of atmospheric air pollution was evaluated on the basis of the behaviour of healthy thallus of the lichen &lt;i&gt;Parmelia physodes&lt;/i&gt;, analysis of fluorine and sulphur content in this thallus and in the bark substrate and the F and SO&lt;sub&gt;2&lt;/sub&gt; concentrations in the air.

Growth and Physiological Responses of Rangpur Lime Seedlings Irrigated by a Prototype Subirrigation Tray

Citrus rootstock production in Brazil commonly uses manual overhead irrigation systems to water plants. Manual irrigation systems present low efficiency, apply more water than needed, and result in release of nutrients and pesticides into the soil with a potential to contaminate groundwater. Closed irrigation systems that avoid the disposal of nutrient solutions like subirrigation can be used to increase production efficiency and reduce the environmental contamination. Our objective was to evaluate the effect of subirrigation applied by a prototype tray on plant growth and morphological and physiological responses of Rangpur lime (Citrus limonia Osbeck ‘Limeira’) seedlings subjected to different water levels in conic containers filled with pine bark substrate. We tested three treatments: T1) subirrigation with water reaching two-thirds of the container height (8 cm); T2) subirrigation with water reaching one-third of the container height (4 cm); and T3) control with manual overhead irrigation. Subirrigation resulted in higher plant growth of Rangpur lime seedlings. At 90 days after sowing (DAS), we observed significant effects of T1 over the other treatments on plant growth, as indicated by higher total dry mass (P = 0.0057), shoot/root ratio (P = 0.0089), shoot height (P = 0.0004), leaf area (P = 0.0005), and root length (P = 0.0333). The number of bifurcations was 400% higher in T3 than at the subirrigated treatments, which can lead to an increase in the labor costs for pruning. Seedlings grown under T1 presented leaf water potential 13% higher compared with T3 at predawn, which was the time of highest stomatal efficiency, presenting the lowest water loss, maximum stomatal closure, and higher transpiration at lower stomatal resistance. T2 plants displayed intermediate water status with a water potential 5% higher than T3. T3 plants showed a higher transpiration rate under maximum stomatal closure, reducing leaf water potential. The subirrigated treatment with water level of two-thirds of container height (8 cm) induced higher plant growth and shortened the crop cycle, anticipating the transplanting to the next phase (grafting) with the possibility of reducing production costs in the nursery.

Solute Transport through a Pine Bark-based Substrate under Saturated and Unsaturated Conditions

An understanding of how dissolved mineral nutrient ions (solutes) move through pine bark substrates during the application of irrigation water is vital to better understand nutrient transport and leaching from containerized crops during an irrigation event. However, current theories on solute transport processes in soilless systems are largely based on research in mineral soils and thus do not necessarily explain solute transport in soilless substrates. A study was conducted to characterize solute transport through a 9 pine bark:1 sand (by volume) substrate by developing and analyzing breakthrough curves (BTCs). Columns filled with pine bark substrate were subjected to the application of a nutrient solution (tracer) and deionized water under saturated and unsaturated conditions. Effluent drained from the columns during these applications was collected and analyzed to determine the effluent concentration (C) of the bulk ions in solution through electrical conductivity (EC) and nitrate (NO3–), phosphate, and potassium (K+) concentrations. The BTCs were developed by plotting C relative to the concentration of the input solution (Co) (i.e., relative concentration = C/Co) as a function of the cumulative effluent volume. Solutes broke through the column earlier (i.e., with less cumulative effluent) and the transition from C/Co = 0 to 1 occurred more abruptly under unsaturated than saturated conditions. Movement of the anion, NO3–, through the substrate was observed to occur more quickly than the cation K+. Throughout the experiment, 37% of the applied K+ was retained by the pine bark. The adsorption of K+ to pine bark cation exchange sites displaced calcium (Ca2+) and magnesium (Mg2+), of which the combined equivalent charge accounted for 43.1% of the retained K+. These results demonstrate the relative ease that negatively charged fertilizer ions could move through a pine bark substrate while solution is actively flowing through substrate pores such as during irrigation events. This approach to evaluating solute transport may be used in horticultural research to better understand how mineral nutrients move through and subsequently leach from soilless substrates during irrigation. Expanding this knowledge base may lead to the refinement of production practices that improve nutrient and water use efficiency in container nurseries.

Influence of Pine Bark Particle Size and pH on Cation Exchange Capacity

Cation exchange capacity (CEC) describes the maximum quantity of cations a soil or substrate can hold while being exchangeable with the soil solution. Although CEC has been studied for peatmoss-based substrates, relatively little work has documented factors that affect CEC of pine bark substrates. The objective of this research was to determine the variability of CEC in different batches of pine bark and determine the influence of particle size, substrate pH, and peat amendment on pine bark CEC. Four batches of nursery-grade pine bark were collected from two nurseries, and a single source of sphagnum moss was obtained, separated in to several particle size classes, and measured for CEC. Pine bark was also amended with varying rates of elemental sulfur and dolomitic limestone to generate varying levels of substrate pH. The CEC varied with pine bark batch. Part of this variation is attributed to differences in particle size of the bark batches. Pine bark and peatmoss CEC increased with decreasing particle size, although the change in CEC from coarse to fine particles was greater with pine bark than peatmoss. Substrate pH from 4.02 to 6.37 had no effect on pine bark CEC. The pine bark batch with the highest CEC had similar CEC to sphagnum peat. Amending this batch of pine bark with sphagnum peat had no effect on composite CEC.

Accumulation of Mn in Leaves of Rosmarinus officinalis Cultivated in Substrates of Pine Bark

Rosmarinus officinalis is an important aromatic shrub cultivated for medicinal, culinary, and ornamental uses. To assess growth, the contents of trace metals cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), lead (Pb), and zinc (Zn) and macronutrients calcium (Ca), magnesium (Mg), potassium (K), nitrogen (N), and phosphorus (P) were measured in these plants cultivated on two substrates: pine bark (PB, pH 4.0, 80.5% organic matter) and pruning wastes–biosolids (BS, pH 6.9, 47.5% organic matter). These plants, initially of 3.5 ± 0.5 g dry weight and 31.1 ± 6.9 cm, were maintained under greenhouse conditions for 7 months. Nutrient solution samples were taken from each substrate in situ by rhizon probes, indicating that the concentrations of soluble Mn and Zn in PB were significantly greater than in the nutritive solution BS. At the end of the assay, the dry weight of leaves and height was significantly greater in plants cultivated in BS (40.0 ± 2.2 g and 75.9 ± 14.3 cm) than in PB (27.5 ± 4.0 g and 62.4 ± 10.2 cm). Plants cultivated in PB showed slight chlorosis, attributed to the high concentration of Mn in leaves (106.6 ± 7.8 mg kg−1), which was much greater than in plants cultivated in BS (8.2 ± 0.9 mg kg−1). The concentration of toxic metals Cd and Pb in plants cultivated on both substrates did not exceed the recommended levels for consumption of the leaves as condiment. If R. officinalis is cultivated on the substrate of pine bark to acid pH for food or medicinal use, the accumulation of Mn must be considered.

The effect of some cultivation conditions on properties of leaves of the container-produced species Alnus glutinosa (L.) Gaertn

Plants differ in their reactions to unfavourable environmental conditions and the effect of the acting factors directly and indirectly results in changes in a number of plants organs. The leaves are vegetative organs and as such they are completely exposed to external conditions. Most markedly these conditions affect the assimilative organs. The objective of the present study was to evaluate the effect of four substrates and two sites differing in light intensity on the leaf morphology of the model plant species Alnus glutinosa (L.) Gaertn. The used substrates were the commercial peat-bark substrate (RKS II), sand and bark substrate. With these substrates the soil conditioner TerraCottem was applied at a rate of 5 g per one litre of the substrate. The experimental plants were grown in 2-litre containers. The focus of evaluations of the individual treatments was on some leaf properties. TerraCottem showed that it had a positive effect also on the leaf area ratio and on leaf efficiency. The number of leaves varied. The effect of the substrate and of the light intensity was identical; the latter parameter was strongly correlated with leaf weight. The shape of the leaves (leaf length/width ratio) and the SLA index responded to the different light intensities. Other parameters were calculated from the results of the measured values which specified in greater detail the effect of the year, media, hydro absorbent and light. Treatments A3 (1 697.60 mm2) and a conrol (1 708.10 mm2) had the smallest leave area. These two treatmens significantly statistically differed frome those in the shade location. In the 2005 year the highest values were measured at the treatment B1 (41.22 m2.kg−1). Next year the values of the SLA were similar.

Origin and distribution of rare earth elements in various lichen and moss species over the last century in France

Rare earth elements (REE) are known to be powerful environmental tracers in natural biogeochemical compartments. In this study, the atmospheric deposition of REE was investigated using various lichens and mosses as well as herbarium samples from 1870 to 1998 from six major forested areas in France. The comparison between the REE distribution patterns in organisms and bedrocks showed a regional uniformity influence from dust particles originating from the bedrock and/or soil weathering that were entrapped by lichens and mosses. These lithological signatures were consistent over the last century. The REE patterns of different organism species allowed minor influence of the species to be highlighted compared to the regional lithology. This was even true where the morphological features played a role in the bioaccumulation levels, which were related to the variable efficiency in trapping atmospheric dust particles. A comparison between REE profiles in the organisms and bark indicated a lack of influence of the substrate on lichen REE content. Lichens and mosses appear to be robust passive monitors of REE atmospheric deposition over decades because the mineral data was preserved in herbarium samples despite organic degradation being shown by carbon isotopes and SEM observations. To overcome the bias of REE concentration that resulted from organic degradation, the use of a normalized method is recommended to interpret the historical samples.

Water Use of Hydrangea macrophylla and Gardenia jasminoides in Response to a Gradually Drying Substrate

As a result of the lack of quantitative data regarding specific water requirements of ornamental species, precision irrigation can be a difficult task for nursery growers. One challenge for growers is that it is not clear how much of the water in soilless substrates is actually available for plant uptake. Substrate moisture release curves (MRC) have been used to predict the amount of plant-available water in soilless substrates, yet there is little information about whether there are differences among species in their ability to extract water from substrates. The objectives of this study were to determine 1) the hydraulic properties of a composted pine bark substrate; and 2) how water uptake in Hydrangea macrophylla and Gardenia jasminoides was affected by decreasing substrate volumetric water content (VWC). As the substrate VWC decreased from 0.38 to 0.17 m3·m−3, substrate matric potential decreased from –4.0 to –69 kPa, whereas hydraulic conductivity decreased from 0.115 to 0.000069 cm·d−1. To measure plant water uptake in a drying substrate, growth chambers were used to provide stable environmental conditions that included continuous lighting to prevent diurnal fluctuations in water use. Water use by H. macrophylla ‘Fasan’ started to decrease at a higher VWC (0.28 m3·m−3) than G. jasminoides ‘Radicans’ (0.20 m3·m−3). Plant water uptake stopped at a VWC of 0.16 m3·m−3 in H. macrophylla and 0.12 m3·m−3 in G. jasminoides. The results show that H. macrophylla is less adept at extracting water from a drying substrate than G. jasminoides. Traditionally, plant-available water in soilless substrates has been studied using substrate MRCs. Our data suggest that substrate hydraulic conductivity may be an important factor controlling water availability to the plants. In addition, there are important differences among species that cannot be detected by only looking at substrate hydraulic properties.

In vitro storage under slow growth and ex vitro acclimatization of the ornamental bromeliad Acanthostachys strobilacea

An in vitro short-term storage method for Acanthostachys strobilacea (Schult. f.) Link, Klotzsch & Otto plants and subsequent ex vitro acclimatization were examined. Seedlings were cultured in vitro at 20, 15, and 10°C (low temperatures) and at 25°C (control) for 30, 60, and 90days. After each period, the plants were transferred to trays containing Pinus bark substrate and were maintained at 25°C for 60days. After 90days of in vitro culture, the lowest biometric parameters mean values were found for the plants grown at 10°C (approximately 4 times smaller than control). These plants were successfully acclimatized with 100% survival and rapid regrowth, while they exhibited a similar phenotype and chlorophyll content to the control treatment. The results showed that 10°C is appropriate for the short-term storage of A. strobilacea plants when cultivated in vitro.

HyLogger™ near-infrared spectral analysis: a non-destructive mineral analysis of Aboriginal Australian objects

Cultural heritage materials from Indigenous cultures often use geological raw materials such as natural rock and mineral pigments. For analysis, these complex human-altered materials require high-resolution, non-destructive methods, and in the case of intricate designs, a point-by-point analysis and mapping capability is desirable. The CSIRO Australia HyLogger™ technology has been adapted from mineral exploration and mining applications to the high-resolution non-destructive infrared and visible light spectroscopic mineral analysis of Aboriginal Australian objects. Aboriginal Australian people primarily applied mineral pigments such as hematite and kaolinite to wood, fibre, bark, resin or other organic substrates, making non-destructive in situ scientific analyses of cultural objects challenging. This proof of concept study demonstrated the utility of the near-IR technology for the visual and mineralogical analysis of six Aboriginal Australian objects, of varying size and pigment application, as case studies for the development of methods to identify and differentiate types of mineral pigments regardless of the substrate or binder. While many identified pigments such as hematite and goethite were expected for the red, orange and yellow pigments, HyLogger™ in combination with The Spectral Geologist™ software identified additional mixtures of previously unknown mineral components. White minerals, such as calcite and pyrophyllite, were identified along with kaolinite in mixtures in white pigments on the artefacts. Analyses of individual spectra were used for interpretation of spectral features for specific pigments. Additionally, classes of pigment groups were identified for spectral analysis. This manuscript presents the novel application of the near-IR technology to Australian Aboriginal artefacts for characterisation and high-resolution near-IR spectroscopy of applied mineral pigments. These results challenge and add to prior knowledge about the mineralogical composition of traditional Aboriginal Australian inorganic pigments.

In Vitro Propagation of Alexandrian Laurel (Danae racemosa L. Moench), a Valuable Ornamental Plant

To overcome the limitations of traditional propagation, this research was initiated to develop an alternative means for efficient production of Alexandrian laurel (Danae racemosa L. Moench). An in vitro propagation protocol has been developed for Danae racemosa L. Moench using seeds as a source of material for culture initiation. Seedlings were produced after seeds were cultured for 3 month on MS (Murashige and Skoog, 1962) medium. Shoot multiplication occurred on MS medium with or without 6-benzylaminopurine (BAP) with 100% multiplication percentage. However, shoot number was significantly increased from an average of 2.8 to more than six with the addition of 5 or 25 μM BAP. Among two indole-3-butyric acid (IBA) treatments tested for rooting of seedlings, incorporation of 5 μM IBA in MS medium significantly increased rooting percentage to 86.4% compared with 71.2% without IBA. The greatest number of roots (three) was produced by 5-minute IBA pulse. However, both IBA treatments significantly reduced root length. The longest root (12.8 mm) was observed on MS medium without any IBA treatment and the shortest (6.1 mm) was produced by IBA pulse. In vitro-propagated plantlets grew well after transfer to a substrate of peat and pine bark (1:1) in the greenhouse. No morphological variation was observed.

Produção de mudas de alface sob diferentes substratos e proporções de casca de arroz carbonizada

O sucesso na produção de alface é iniciado pela obtenção de mudas de boa qualidade, pois se mal formadas darão origem a plantas com produção abaixo de seu potencial genético. Assim, objetivou-se avaliar a produção de mudas de alface sob diferentes substratos e proporções de casca de arroz carbonizada. O delineamento experimental foi inteiramente casualizado, com quatro repetições. Os tratamentos foram dispostos em esquema fatorial 4x5, sendo quatro tipos de substratos (PlantHort I, PlantHort II, PlantHort IIIe substrato comercial Plantmax®) e cinco níveis palha de arroz carbonizada (0, 25, 50, 75, 100%). As características orfofisiológicas avaliadas foram teor de clorofila a e b, área foliar, área foliar específica, razão da área foliar, razão da massa foliar, caulinar e radicular aos 24 dias após a semeadura. A adição de proporção crescente de casca de arroz carbonizada promove redução nas características morfofisiológicas das mudas de alface. Independente da proporção de casca, os substratos PlantHort I, PlantHort II e PlantHort III, promovem maior produção e distribuição equilibrada de fotoassimilados na parte aérea/raiz, em comparação ao substrato Plantmax®, que ssegura nessa condição apenas o crescimento do sistema radicular em detrimento do aéreo. Os substratos alternativos proporcionam produção de mudas de alface de melhor qualidade em detrimento do substrato comercial Plantmax®.

Effect of Pre and Post Moisture Level on Preemergence Control of Hairy Bittercress (Cardamine hirsuta L.) with Flumioxazin

Moisture is an important component to activate preemergence herbicides; however, this aspect had not been investigated in soilless substrate. The objective of this study was to evaluate the influence of pre-application moisture levels and post-application irrigation levels in the preemergence control of hairy bittercress with flumioxazin in a pine bark substrate. Three similar experiments were conducted over a 13-month period. Treatments were a factorial arrangement at the following variables: three pre-application moisture levels (dry, medium and wet), two flumioxazin formulations (granular and spray), two flumioxazin rates [0.28 and 0.42 kg ai·ha−1 (0.250 and 0.375 lb ai·A−1)] and four levels of single-event, post-application irrigation [0.6, 1.3, 2.5 and 5.1 cm (0.25, 0.50, 1.00 and 2.00 in)]. Treated pots were overseeded with 25 hairy bittercress at 1 week after flumioxazin application. Pre-application moisture did not affect the flumioxazin efficacy at any time and treatment. The spray formulation (SureGuard) provided maximum fresh weight control (≥ 99%) in weed counts up to 12 weeks after application, regardless of rate, pre-moisture level or post-irrigation level. The granular formulation (BroadStar) was less effective than spray formulation, and efficacy was improved with the higher rate and higher levels of post-application irrigation (Experiments 1 and 3).

Lichen monitoring as a potential tool in environmental forensics: case study of the Cu smelter and former mining town of Karabash, Russia

Abstract The aim of this paper is to showcase the use of lichens in environmental forensics from an assessment of atmospheric deposition in and around the Cu smelter and former mining town of Karabash, Ural Mountains of Russia. Hypogymnia physodes was collected on its bark substrate in July 2001 from a ‘reference’ site ( c. 25 km SW of Karabash) and transplanted to 10 stations along an approximately 60 km SSW–NNE transect centred on Karabash. Transplants were collected after 2 and 3 month exposure periods. The elemental compositions of Hypogymnia and potential sources of particulates in the study area (smelter blast furnace and converter dusts, wastes, tailings, road dusts, metallurgical slags and top soils) were determined by inductively coupled plasma optical emission spectrometry (ICP-OES) and quadrupole ICP mass spectrometry (ICP-MS), and the Pb isotope compositions of the lichens and smelter dusts by multicollector ICP-MS. Particulates on lichen surfaces were analysed by scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX). The method of lichen transplantation, combined with multi-element and surface particle elemental analysis, high-precision Pb isotope ratio determinations and modelling, was shown to be useful for the tracing of the smelter signal, and components from different smelter processes, for more than 25 km from Karabash town. The lichen monitoring methodology is discrete and comparatively low cost, enabling atmospheric deposition from natural and anthropogenic sources to be determined over short (&lt;3 month) periods, and is therefore a valuable qualitative tool for environmental forensics.