Alley cropping and mulching withErythrina poeppigiana (Walp.) O. F. Cook andGliricidia sepium (Jacq.) Walp.: effects on maize/weed competition

The potential of allye cropping systems to sustain a high productivity with low external inputs and the reduction of maize/weed competition through weed suppression in different alley cropping and sole-cropped mulched systems was studied in Costa Rica at CATIE. Data were recorded eight years after establishment of the experiment. Plant residues ofErythrina poeppigiana trees (10 t/ha dry matter) planted at 6 by 3 m reduced weed biomass by 52%, whileGliricidia sepium trees (12 t/ha dry matter) planted at 6 by 0.5 m reduced weed biomass by 28%, in comparison to controls.Erythrina had a considerable impact on grass weeds, whileGliricidia reduced the incidence of some dicot weeds. Weed competition significantly reduced maize yield in all systems. Nevertheless weed suppression contributed to the higher maize grain yield underErythrina andGliricidia alley cropping of 3.8 t per hectare as opposed to the unmulched control yield of 2.0 t per hectare.     

Antagonismusin vitro vonBacillus spp. gegenüberRhizoctonia solani undPythium spp.

Zusammenfassung Es konnten 132Bacillus-Stämme isoliert und gegenüber7 Rhizoctonia-solani- und 6Pythium-Stämmen auf Antagonismusin vitro untersucht werden. Die gefundenen Antagonisten hemmten die Pilzisolate unterschiedlich stark, so daß Gemische von Antagonisten für die Praxis zu empfehlen sind.

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Antagonismin vitro ofBacillus spp. againstRhizoctonia solani andPythium spp.

There were 132Bacillus-strains isolated and tested for antagonism against 7 strains ofRhizoctonia solani and 6 strains ofPythium spp. The isolated antagonists didn't show a uniform effect against the tested strains ofRhizoctonia solani andPythium spp. For an application in practice it will be better to use a mixture of antagonists.

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Mit 4 Abbildungen und einer Tabelle     

Surveying farmers' agroforestry plots: experiences in evaluating alley-cropping and tree border technologies in Western Kenya

Evaluation of existing on-farm agroforestry plots should provide useful supplementary information for the design of improved agroforestry systems, in both research and development projects. Such evaluation has been little used, however, largely due to the methodological difficulties of surveying highly variable on-farm plots, and difficulties in identifying key variables for measurement. This paper describes a set of methods and tools used in evaluating plots of alley-cropping and tree borders around crop fields established by farmers working with the CARE Agroforestry Extension Project in western Kenya. Details of survey design, sampling, and implementation are discussed, and suggestions made for carrying out agroforestry surveys in other projects. A condensed version of the questionnaire is appended.     

Fragen der insektiziden Wirkung bifluoridhaltiger Holzschutzmittel

Zusammenfassung Es wurde experimentell untersucht, ob ein bifluoridhaltiges Holzschutzsalz bei Anwendung in der zur vorbeugend-insektiziden Behandlung vorgeschriebenen Dosierung von 50 g/m² Holzoberfläche gleichzeitig eine bekämpfende Wirkung aufweist. Als Versuchstiere dienten im Durchschnitt 7 mg schwere, d. h. verhältnismäßig kleine Larven des Hausbockkäfers (Hylotrupes bajulus L.). Als Ergebnis war zu verbuchen, daß je nach Schärfe der Versuchsbedingungen 77–100% der Larven abstarben. Dieses Resultat wurde mit Holzproben erzielt, deren Behandlung 6 1/2 Jahre zurücklag. Aufgrund der Kenntnis über den Verlauf der Fluorabgabe aus geschütztem Holz ist anzunehmen, daß der ermittelte Bekämpfungseffekt noch eine weitere Reihe von Jahren vorhält.Diese Festellungen beziehen sich ausdrücklich lediglich auf kleinere Larven. Halbwüchsige und größere Larven, gegen die sich in der Baupraxis vorgenommene Bekämpfungsmaßnahmen hauptsächlich richten, bedürfen zur Abtötung stärkerer Dosierungen. Es wird daher davor gewarnt, die vorgeschriebene Bekämpfungsdosis von 100 g/m² zu unterschreiten.

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Summary Tests were carried out to show, if a wood-preserving salt containing fluorine, when applied in the dosage of 50 g/m² surface of wood as prescribed for prophylactic insecticide treatment, has also controlling capacities. Larvae of the House Longhorn Beetle (Hylotrupes bajulus L.) of an average weight of 7 mg, i. e. relatively small ones, were used as test insects. In the experiments, under conditions of different severity, mortalities of 77–100% of the larvae were registered. These results were attained with pieces of wood which were treated with the wood-preserving agent 6 1/2 years ago. According to our knowledge of the progressive loss of fluorine out of treated wood it can be expected that the controlling effect found in the experiments will last for several more years.It must be emphasized, however, that these results were reached only with relatively small larvae of the House Longhorn Beetle. To kill halfgrown larvae or larger ones, i. e. those, against which pest-control measures in buildings usually are directed, higher dosages of the salt are required. Under these circumstances one should be cautious not to apply less than the dosage of 100 g/m² prescribed for control measures.

     

<Emphasis Type="Italic">Pinus halepensis</Emphasis> somatic embryogenesis is affected by the physical and chemical conditions at the initial stages of the process

Pinus halepensis has been described as a drought-tolerant species with high plasticity to growth in different environments. Its eco-physiological characteristics could facilitate the use of this species in large afforestations in the future scenery of climate change. Somatic embryogenesis is a biotechnological tool with potential for large-scale clonal propagation. In order to establish an improved regeneration protocol for Pinus halepensis, the effects of different temperatures (18, 23, and 28 °C) and water availability conditions (2, 3, and 4 g L^?1 Gelrite^®), during initiation of embryonal masses on the rate of initiation, proliferation, maturation, and the number of embryos developed, were evaluated. It was found that environmental conditions during the initiation stage of Pinus halepensis somatic embryogenesis influence the success of initiation and proliferation. In contrast, there was no effect of these conditions on the maturation rates and the number of somatic embryos. Somatic embryos were obtained in all treatments tested, indicating that plants can be produced from extreme conditions of induction, such as high temperatures (28 °C) and low water availability conditions (4 g L^?1).     

Establishment of a high-frequency regeneration system in <Emphasis Type="Italic">Cerasus humilis</Emphasis>, an important economic shrub

Cerasus humilis is a species of small, perennial, drought-resistant and multipurpose deciduous shrub grown in arid and semi-arid conditions in northern China. In this study, an efficient protocol for the rapid micropropagation of C. humilis has been standardized using stem and/or leaf explants. Direct multiple shoot induction was observed when the stem explants were cultured on Murashige and Skoog (MS) medium supplemented with different plant growth regulators. The highest shoot induction was obtained when stem explants from adult trees were cultured on MS medium supplemented with 2.0 mg L^?1 6-benzyladenine (6-BA) and 0.9 mg L^?1 α-naphthaleneacetic acid (NAA). The leaf and stem explants cultured on MS medium with 1.0 mg L^?1 6-BA and 0.6 mg L^?1 NAA, and 0.5 mg L^?1 6-BA and 0.8 mg L^?1 NAA, respectively, produced the highest induction frequency of callus. Maximum proliferation of callus was observed on MS medium containing a combination of 0.5 mg L^?1 6-BA with 0.6 mg L^?1 2,4-dichlorophenoxyacetic acid (2,4-d). Optimal shoots differentiated from callus were obtained on MS medium supplemented with 5.0mg L^?1 6-BA and 0.9 mg L^?1 NAA. In vitro rooting was achieved on half-strength (1/2) MS medium containing 0.5 mg L^?1 NAA. Rooted plantlets were hardened under control conditions and successfully acclimatized under field conditions.     

Chemical composition,antioxidant and antibacterial activities of extracts from <Emphasis Type="Italic">Schinus molle</Emphasis> wood branch growing in Egypt

In the present work, for the first time, the chemical components of essential oils (EOs) and extracts from wood branch (WB) resulted from the tree pruning wastes of Schinus molle L. grown in Egypt were evaluated for their antioxidant and antibacterial activities. EOs, methanol (ME), dichloromethane (DCME) and water (WE) extracts as antioxidant and antibacterial activities were measured. Total phenolic and flavonoid contents as well as analysis of extracts by gas chromatography–mass spectrometry (GC–MS) were reported. The major components in EOs were α-elemol, β-pinene, and α-phellandrene, in ME were 6-(4-chlorophenyl)-3-cyano-4-(N-benzylpiperazino)-2H-pyran-2-one, and 2-naphthalene methanol, decahydro-α,α,4a-trimethyl-8-methylene, in DCME were 12-methyl-E,E-3,13-octadecadien-1-ol, and 1,2-benzenedicarboxylic acid, dioctyl ester, and in WE were β-eudesmol, and (Z,Z,Z)-9,12,15-octadecatrienoic acid, 2,3-dihydroxypropyl ester. The highest total antioxidant activity was found with EOs (90 ± 1.23 %) and WE (86.30 ± 1.40 %). The lowest IC₅₀ values of 13.11 ± 3.00, and 12.66 ± 2.15 μg/mL were found with WE and EOs, respectively. EOs and WE were observed to have good antibacterial activity against Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Sarcina lutea, Pseudomonas aeruginosa, and Micrococcus luteus. In conclusion, the Schinus molle L. WB EOs and extracts might, indeed, be used as a potential source for pharmaceutical or food industries.     

The Level II aggregated forest soil condition database links soil physicochemical and hydraulic properties with long-term observations of forest condition in Europe

Key message

Aggregated, consolidated, and derived soil physicochemical data of 286 ICP Forests Level II plots were completed with soil hydraulic properties for integrated use with forest monitoring data. Database access should be requested at http://icp-forests.net . Metadata associated available at https://metadata-afs.nancy.inra.fr/geonetwork/apps/georchestra/?uuid=153e599e-6624-4e2b-b862-8124386ea9cd&hl=eng

Context

The ICP Forests database is one of the most comprehensive forest ecosystem datasets in Europe and contains the accumulated results of more than two decades of harmonised forest monitoring all over Europe.

Aims

The aim of this paper is to share knowledge on the ICP Forests Level II soil data for broader use among forest scientists.

Methods

After standard analysis, quality checks, aggregation, and calculation of derived variables (e.g. nutrient stocks, base saturation, C:N ratio, and water retention parameters), data have been gathered into a static database (AFSCDB.LII.2.2), which will be updated to new versions as soon as new measurements become available.

Results

The database provides a basis for the combined evaluation of up to 130 unique soil variables of 286 plots with dynamic data on tree growth, ground vegetation, foliar chemistry, crown condition, tree phenology, leaf area index, ozone injury, litterfall, soil solution chemistry, deposition, ambient air quality, and meteorological data assessed on the same plots.

Conclusion

The unprecedented comprehensiveness and level of detail in this newly aggregated database may overcome existing restrictions so far impeding the realisation of large-scale forest ecosystem studies in Europe.

     

Analysis of sawn lumber production from logging residues of branchwood of <Emphasis Type="Italic">Aningeria robusta</Emphasis> and <Emphasis Type="Italic">Terminalia ivorensis</Emphasis>

One way of meeting the supply demands of the wood industry is through the reduction of waste in timber processing. It has been estimated in Ghana that for every tree felled, nearly 50% of the tree volume is left in the forest in the form of branches, crownwood, and stumps. In this study, the potential of utilizing branchwood as raw material from logging residues to help meet the timber demands of the downstream processing sector was analyzed experimentally. The sawing characteristics of the branchwood of Aningeria robusta and Terminalia ivorensis with diameters in the range 10–25 cm using live sawing and cant sawing methods were determined using a randomized complete block design, 2 × 4 factorial with three replications. Experimental results indicate that, the relative lumber value yields for first and second grade boards of A. robusta and T. ivorensis branches were 25 and 20%, respectively, while the green lumber volume yields were 40 and 32%, respectively. A high proportion of sapwood and the occurrence of washboarding in T. ivorensis contributed to that species’ relatively low lumber value and volume yield. The experimental results further indicate that the sawing technique used had no significant influence on lumber yields. However, at 5% level of significance, significant differences in lumber yield existed between some of the diameter classes.