<Emphasis Type="Italic">Ophiostoma</Emphasis> species associated with bark beetles infesting three <Emphasis Type="Italic">Abies</Emphasis> species in Nikko,Japan

Ophiostoma species were isolated from bark beetles and Abies mariesii, A. veitchii and A. homolepis attacked by the beetles in Nikko, Tochigi, central Honshu, Japan. One to two Ophiostoma species were frequently isolated from each species of bark beetle. Ophiostoma subalpinum was the most common associate of Cryphalus montanus. Ophiostoma sp. B as well as O. subalpinum was a common fungus associated with Polygraphus proximus. Ophiostoma europhioides was isolated from Dryocoetes hectographus and D. autographus as one of the common associates. Ophiostoma sp. J and Ophiostoma sp. S were frequently isolated from D. autographus and D. striatus, respectively. These fungi seem to have specific relationships with particular bark beetles. Ophiostoma sp. B, Ophiostoma sp. J and Ophiostoma sp. S have unique morphological characteristics and appear to be new species. Five trees of A. veitchii, approximately 43 years old, were inoculated with five Ophiostoma species to assess the relative virulence of the fungi. Ophiostoma subalpinum, Ophiostoma sp. B, and O. europhioides had relatively higher virulence than the other species studied.     

Chemical alterations induced by <Emphasis Type="Italic">Pycnoporus sanguineus</Emphasis>/<Emphasis Type="Italic">Aspergillus flavipes</Emphasis> co-cultures in wood from different tree species

Chemical alterations following inoculation of Acacia mearnsii, Eucalyptus dunnii, E. grandis, and E. macarthurii with a Pycnoporus sanguineus/Aspergillus flavipes co-culture were investigated. Several wood chemical parameters were measured using standard methods from the pulp and paper industry. The data were described and analyzed using univariate as well as multivariate statistical techniques. Boxplots and in particular biplots show clearly how the chemical composition of each tree species was differently affected by the co-culture. Lignin content was significantly decreased in A. mearnsii, while E. dunnii showed a decrease in cellulose content. The results, therefore, indicate that the manner in which wood is degraded by a specific fungal co-culture depends on the tree species involved. This phenomenon should be considered when selecting fungi for bio-pulping.     

Micropropagation of <Emphasis Type="Italic">Salvadora</Emphasis><Emphasis Type="Italic">persica</Emphasis>-a tree of arid horticulture and forestry

A micropropagation method for Jaal (Salvadora persica)—a tree of arid horticulture and forestry has been developed. Nodal segments of fresh shoot sprouts originated from axillary buds obtained from a plant around 35–40 years old lopped plant were used as explants for establishment of in vitro cultures. Surface-sterilized explants produced optimum number of shoots through activation of axillary buds on Murashige and Skoog’s (MS) medium containing 8.88 μM BA (6-benzyladenine) + additives (25 mgl⁻¹ each of adenine sulphate, arginine, citric acid, 50 mgl⁻¹ ascorbic acid). The shoot multiplication was influenced by the successive transfer of the mother explants for 4–5 passages. The maximum number (23.1 ± 0.73 shoots per explant) of shoots were regenerated on MS supplemented with 1.11 μM BA + 1.16 μM Kn (Kinetin) + 0.54 μM NAA (α-naphthalene acetic acid). About 90% shoots pulse-treated with a combination of 2460.27 μM Indole-3-butyric acid (IBA) + 494.56 μM NOA (2-naphthoxy acetic acid) were rooted ex vitro on soilrite within 15–18 days. Over 80% cloned plantlets were hardened successfully in a green house and transferred to polybag/pots.     

Successful <Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated transformation of <Emphasis Type="Italic">Populus tomentosa</Emphasis> with apple <Emphasis Type="Italic">SPDS</Emphasis> gene

The problem of salinized soils has become one of the most serious constraints to agricultural and forest productivity. With the purpose of enhancing salt stress tolerance of Populus tomentosa, we transformed this tree species with spermidine synthase （SPDS） genes derived from an apple by an Agrobacterium-mediated method. Four transgenic clones were confu＇med by PCR and Southern blot analysis. As well, the expression of introduced SPDS genes was analyzed by real-time quantitative PCR.     

Effects of <Emphasis Type="Italic">Eucalypt</Emphasis> and <Emphasis Type="Italic">Acacia</Emphasis> plantations on soil water in Sumatra

Indonesia’s pulp and paper industry needs a large area of sustainably grown plantations to support its continued development. Acacia mangium has been the key species underpinning the pulp and paper industries in Sumatra, however increased disease pressure on A. mangium is expected to require large-scale conversion of Acacia plantations to Eucalyptus in the near future. The effect of such a large scale change in plantation species on soil moisture, for both tree production, and catchment hydrology is unknown. In this study we sought to characterize the impacts of plantation species (Acacia or Eucalyptus) and nitrogen management, on soil moisture, soil water depletion and depth to groundwater under stands of Acacia mangium and Eucalyptus pellita over the first 2–3 years after establishment. The study was conducted in experiments at four sites in Sumatra, Indonesia. Soil moisture and soil water depletion were not influenced by plantation species or fertilizer treatment. Soil moisture content and soil water depletion were strongly influenced by shallow groundwater at two of the four sites, however depth to groundwater did not influence stem growth. Results from the field trials cautiously suggest that large scale conversion of Acacia mangium to Eucalypt species in these regions is unlikely to result in increased moisture stress, nor is conversion of plantation species likely to lead to substantial differences in catchment hydrology. This study demonstrated the importance of conducting multi-site studies when investigating biophysical relationships in forest/plantation systems.     

Biochemical changes associated with flowering in <Emphasis Type="Italic">Bambusa arundinacea</Emphasis> and <Emphasis Type="Italic">Bambusa nutans</Emphasis>

Biochemical changes associated with flowering in Bambusa arundinacea Linn and Bambusa nutans Wall. ex Munro were analyzed. Gregarious flowering was initiated in natural areas and plantations of B. arundinacea in late 2014 and reached full bloom in early 2015, whereas sporadic flowering recorded during 2014–2015 in vegetatively propagated plants of B. nutans. Leaf and nodal shoot samples from flowering culms/shoots and nonflowering culms/shoots were collected in February 2015 at the initiation of fruit filling, then analyzed and compared for soluble sugars, phenols and peroxidase activity. In both species sugars were higher in leaves of flowering culms/shoots and lower in nodal shoots of flowering culms/shoots compared to the nonflowering. Phenols were lower in leaves and nodal shoots of flowering B. arundinacea, but higher in leaves and decreases in nodal shoots of B. nutans. Peroxidase activity increases in leaves and nodal shoots of B. arundinacea after flowering but increases in nodal shoots and decreases in leaves of B. nutans.     

Insecticidal properties of <Emphasis Type="Italic">Thymus persicus</Emphasis> essential oil against <Emphasis Type="Italic">Tribolium castaneum</Emphasis> and <Emphasis Type="Italic">Sitophilus oryzae</Emphasis>

Red flour beetle Tribolium castaneum (Herbst) and rice weevil Sitophilus oryzae (L.) are considered to be the major insect pests in storage. Essential oils from aromatic plants are recognized as proper alternatives to fumigants. Thymus persicus (Ronniger ex Rech. f.) is one of these plants that have medicinal properties and is indigenous to Iran. The essential oil was obtained from aerial parts of the plant and analyzed by GC and GC–MS. Carvacrol (44.69%) and thymol (11.05%) were the major constituents of the oil extracted. In this experiment, fumigant toxicity of the essential oil was studied against T. castaneum, S. oryzae at 27 ± 1°C and 60 ± 5% RH in dark condition. The adult insects were exposed to the concentrations of 51.9, 111.1, 207.4 and 370.4 μl/l air to estimate median lethal time (LT₅₀) values. The fumigant toxicity was increased in response to increased essential oil concentrations. The LT₅₀ values at the lowest and the highest concentrations tested were ranged from 28.09 to 13.47 h for T. castaneum, and 3.86 to 2.30 h for S. oryzae. It was found that S. oryzae adults were much more susceptible to the oil than T. castaneum. After 24 h of exposure, the LC₅₀ values (95% fiducial limit) for T. castaneum and S. oryzae were estimated to be 236.9 (186.27–292.81) and 3.34 (2.62–4.28) μl/l air, respectively. These results suggest that T. persicus essential oil merits further study as potential fumigant for the management of these stored-product insects.     

Management Effects on Biomass and Foliar Nutritive Value of <Emphasis Type="Italic">Robinia pseudoacacia</Emphasis> and <Emphasis Type="Italic">Gleditsia triacanthos</Emphasis> f. <Emphasis Type="Italic">inermis</Emphasis> in Arkansas,USA

The browse potential of black locust (Robinia pseudoacacia L.) and thornless honey locust [Gleditsia triacanthos f. inermis (L.) Zabel] has not been adequately tested. Our objective was to determine effects of fertilization and pollarding on biomass and foliar nutritive value in separate studies of black locust and thornless honey locust in Arkansas, USA. Shoots were sampled monthly for two consecutive growing seasons in 2002 and 2003 to determine foliar, shoot, and total aboveground biomass, shoot basal diameter, and foliar nutritive value (crude protein and in vitro digestibility). Black locust yielded more foliar biomass when pollarded at 50 or 100 cm and fertilized with 600 kg P ha⁻¹, than at 5 cm with or without P, averaging 3.5 Mg dry matter ha⁻¹. Black locust foliar crude protein and in vitro dry matter digestibility ( ≤ 170 and 534 g kg⁻¹, respectively) decreased as leaves aged, but still met maintenance needs for beef cattle (Bos taurus L.). Thornless honey locust had little agronomic potential because of slow establishment, low foliar yield (330 kg ha⁻¹), and a 2% reversion to undesirable thorny phenotype. Black locust should be considered for livestock browse when drought induces semi-dormancy of herbaceous forages.     

Pest risk analysis of <Emphasis Type="Italic">Metcalfa pruinosa</Emphasis> in Austria

The North American planthopper Metcalfa pruinosa (Say, 1830) (Hemiptera: Flatidae) was accidentally introduced into Europe, and subsequently caused economic damage to orchards and vineyards in some South-European countries. In 2003, a mass occurrence of M. pruinosa was discovered in Vienna, followed by new infestations of several sites. A Pest Risk Analysis was conducted, according to the European and Mediterranean Plant Protection Organization decision support scheme for quarantine pests, to evaluate the risk to Austrian agriculture by M. pruinosa. The highest risk of further introduction into Austria arises from trade of deciduous plants infested with M. pruinosa eggs from Italy and France where this pest is common and which are important trading partners of Austria. Entry by vehicle traffic is considered moderately likely. Active spread by flight of adult M. pruinosa is considered significant only for local dispersal. The CLIMEX^® program was applied to predict M. pruinosa’s potential geographical distribution and to identify areas at risk. In Austria, southern Burgenland and south-east Styria as well as parts of Vienna, Lower and Upper Austria provide the most suitable climate for M. pruinosa’s development. Organic production areas in theses regions are especially at risk of being damaged. To prevent economic impact and for long-term control of M. pruinosa, biological control with its natural enemy Neodryinus typhlocybae (Ashmead 1893) (Hymenoptera: Dryinidae) is recommended.     

Weed control measures in Christmas tree plantations of <Emphasis Type="Italic">Abies nordmanniana</Emphasis> and <Emphasis Type="Italic">Abies lasiocarpa</Emphasis> on agricultural land

Abies nordmanniana and Abies lasiocarpa, established for Christmas tree production in southwestern Norway (58°44′N, 5°38′E), were treated with different weed control methods, including chemicals, use of black plastic mulch, grass or clover as ground cover, living mulch and mechanical hoeing. Ground cover with black plastic mulching resulted in the best growth and quality in A. lasiocarpa; the least favourable treatment was when grasses were allowed to grow close to the trees. Unless measures were taken to remove this competing vegetation, the ground cover grew over the trees, smothering 94% of them. A. nordmanniana plants grew to the same height on plots with no weed control as on plots with thorough weed eradication. Stem diameter decreased on plots with ground vegetation compared to seedlings grown in the weed-free environment. The use of Trifolium repens as ground cover decreased height growth by 30% compared to thorough weed control. Both grasses and clover sown as living mulch, damaged the trees more than did natural weed vegetation.     

Genetic diversity in two threatened species in Vietnam: <Emphasis Type="Italic">Taxus chinensis</Emphasis> and <Emphasis Type="Italic">Taxus wallichiana</Emphasis>

Taxus chinensis and T. wallichiana in have been threatened in their distribution areas in recent decades because of their over-exploitation and reduction and destruction of native habitats. Determining the genetic diversity in populations of the two species will provide guidelines for their protection and preservation. Two hundred and fifteen trees from six populations of T. chinensis and 150 sampled trees of T. wallichiana were sampled. Six microsatellite primer pairs selected from 16 primer pairs were used to investigate genetic variation at the population and species levels. Five yielded polymorphic alleles, and among the 13 putative alleles amplified, 11 were polymorphic (accounting for 76.33 %).Shannon’s information index (I) and percentage of polymorphic bands (PPB) (I = 0.202 and PPB = 67.22 % for T. chinensis; I = 0.217 and PPB = 65.03 % for T. wallichiana). Both species had low levels of genetic diversity (mean H _o = 0.107, H _e = 0.121 for T. chinensis; H _o = 0.095, H _e = 0.109 for T. wallichiana). Genetic differentiation among populations was higher (F _ST = 0.189) for T. chinensis and lower (0.156) for T. wallichiana, indicating limited gene flow (Nm) among populations for T. chinensis (0.68) and T. wallichiana (0.65). Variation among individuals of T. chinensis was 63.59 and 73.12 % for T. wallichiana. Thus, the threatened status of the two conifers is related to a lack of genetic diversity. All populations are isolated in small forest remnants. An ex situ conservation site should be established with a new population for these species that comprises all the genetic groups for the best chance to improve their fitness under environmental stresses.     

Parasitism of different <Emphasis Type="Italic">Trichogramma</Emphasis> species and strains on <Emphasis Type="Italic">Plutella xylostella</Emphasis> L. on greenhouse cauliflower

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is the most important pest of cultivated Brassica worldwide, including those grown in greenhouses like cauliflower. In this article, we evaluate the potential of various species (and various strains of some species) of Trichogrammatidae (Hymenoptera: Chalcidoidea) to control this pest on cauliflower in greenhouse in France. We assessed the parasitism levels on P. xylostella of 17 Trichogrammatidae strains, belonging to 12 different species (2 indigenous strains from France), under greenhouse conditions. Parasitism levels for each of the Trichogrammatidae species and strains were determined on cauliflower leaves (Brassica oleracea botrytis L., Brassicaceae) infested with P. xylostella eggs. Nine strains parasitized 60% (or more) of the P. xylostella eggs. Compared to previous results in laboratory conditions, climatic conditions of the greenhouse did not influence parasitism levels. The presence of the cauliflower plants may have a positive effect on eight strains, a negative effect on four strains and no effect on five strains. Our study points out the importance of including the host plant of P. xylostella when conducting studies aiming to select the most efficient parasitoid against this pest.     

Bioremediation of CCA-treated wood by brown-rot fungi <Emphasis Type="Italic">Fomitopsis palustris</Emphasis>, <Emphasis Type="Italic">Coniophora puteana</Emphasis>, and <Emphasis Type="Italic">Laetiporus sulphureus</Emphasis>

This study evaluated oxalic acid accumulation and bioremediation of chromated copper arsenate (CCA)-treated wood by three brown-rot fungi Fomitopsis palustris, Coniophora puteana, and Laetiporus sulphureus. The fungi were first cultivated in a fermentation broth to accumulate oxalic acid. Bioremediation of CCA-treated wood was then carried out by leaching of heavy metals with oxalic acid over a 10-day fermentation period. Higher amounts of oxalic acid were produced by F. palustris and L. sulphureus compared with C. puteana. After 10-day fermentation, oxalic acid accumulation reached 4.2 g/l and 3.2 g/l for these fungi, respectively. Fomitopsis palustris and L. sulphureus exposed to CCA-treated sawdust for 10 days showed a decrease in arsenic of 100% and 85%, respectively; however, C. puteana remediation removed only 18% arsenic from CCA-treated sawdust. Likewise, chromium removal in F. palustris and L. sulphureus remediation processes was higher than those for C. puteana. This was attributed to low oxalic acid accumulation. These results suggest that F. palustris and L. sulphureus remediation processes can remove inorganic metal compounds via oxalic acid production by increasing the acidity of the substrate and increasing the solubility of the metals.An erratum to this article can be found at     

Enzymatic saccharification and ethanol production of <Emphasis Type="Italic">Acacia mangium</Emphasis> and <Emphasis Type="Italic">Paraserianthes falcataria</Emphasis> wood,and <Emphasis Type="Italic">Elaeis guineensis</Emphasis> trunk

We examined the saccharification and fermentation of meals from Acacia mangium wood, Paraserianthes falcataria wood, and Elaeis guineensis trunk. The levels of enzymatic hydrolysis of cellulose and ethanol production were highest for P. falcataria wood and lowest for A. mangium wood. Ultrasonication pretreatment of meal further increased the rates of hydrolysis and ethanol production in meal from P. falcataria wood. Through this pretreatment, hemicelluloses (xylan and xyloglucan) and cellulose were released in the meal from P. falcataria wood. Loosening of hemicellulose associations can be expected to make P. falcataria wood more useful for bioethanol production.     

Sterile insect technique and <Emphasis Type="Italic">Wolbachia</Emphasis> symbiosis as potential tools for the control of the invasive species <Emphasis Type="Italic">Drosophila suzukii</Emphasis>

Drosophila suzukii, a vinegar fly originated from Southeast Asia, has recently invaded western countries, and it has been recognized as an important threat of a wide variety of several commercial soft fruits. This review summarizes the current information about the biology and dispersal of D. suzukii and discusses the current status and prospects of control methods for the management of this pest. We highlight current knowledge and ongoing research on innovative environmental-friendly control methods with emphasis on the sterile insect technique (SIT) and the incompatible insect technique (IIT). SIT has been successfully used for the containment, suppression or even eradication of populations of insect pests. IIT has been proposed as a stand-alone tool or in conjunction with SIT for insect pest control. The principles of SIT and IIT are reviewed, and the potential value of each approach in the management of D. suzukii is analyzed. We thoroughly address the challenges of SIT and IIT, and we propose the use of SIT as a component of an area-wide integrated pest management approach to suppress D. suzukii populations. As a contingency plan, we suggest a promising alternative avenue through the combination of these two techniques, SIT/IIT, which has been developed and is currently being tested in open-field trials against Aedes mosquito populations. All the potential limiting factors that may render these methods ineffective, as well as the requirements that need to be fulfilled before their application, are discussed.     

Influence of umbrella pine (<Emphasis Type="Italic">Pinus</Emphasis><Emphasis Type="Italic">pinea</Emphasis> L.) stand type and tree characteristics on cone production

Most umbrella pine (Pinus pinea L.) stands are managed as agroforestry systems, whose main production is fruit, due to the edible and highly nutritious kernels, and are frequently associated to natural or seeded pastures and grazing. The stands have low density, in order to enhance crown growth and fruit production. Nevertheless, cone production, both with regard to number and weight, varies greatly between stands, trees and years. In this study were selected three agroforestry systems, representative of umbrella pine stands whose main production is fruit, and one stand representative of the timber production system, where fruit is the secondary production. It was evaluated the variability in cone production as a function of the tree’s diameter at breast height and crown diameter and the individual tree’s competition status. The results indicate that stands managed in agroforestry systems with lower competition and individuals with larger diameter at breast height and crown diameter tend to produce more and heavier cones per tree. The first two principal components of the principal component analysis explain 84 % of the variance in cone production, trees’ dimensions and competition index. Tree competition status has a negative impact on production per tree.     

Aboveground biomass equations for individual trees of <Emphasis Type="Italic">Cryptomeria japonica</Emphasis>, <Emphasis Type="Italic">Chamaecyparis obtusa</Emphasis> and <Emphasis Type="Italic">Larix kaempferi</Emphasis> in Japan

Generic equations are proposed for stem, branch and foliage biomass of individual trees in even-aged pure stands of Cryptomeria japonica, Chamaecyparis obtusa and Larix kaempferi. Biomass data was collected from a total of 1,016 individual trees from 247 stands throughout Japan, and five regression models were assessed by root mean square error, mean bias, fit index (FI), and AIC. The results show that a power equation using diameter at breast height (dbh) and height is the most suitable for all species and components. This equation is more accurate than the familiar power equation that uses ‘dbh² height’, and it expresses the greater volume of branch and foliage mass of trees with a lower height/diameter ratio. A power equation using dbh is more reasonable for models with dbh as the only independent variable and more accurate than a power equation using ‘dbh² height’ for estimating branch and foliage mass. Estimating error for branch and foliage mass is larger than that for stem mass, but the entire aboveground biomass can be estimated with an error of less than 19%, except in the case of small trees with dbh less than 10 cm.     

Comparative efficacy of NeemAzal and local botanicals derived from <Emphasis Type="Italic">Azadirachta indica</Emphasis> and <Emphasis Type="Italic">Plectranthus glandulosus</Emphasis> against <Emphasis Type="Italic">Sitophilus zeamais</Emphasis> on maize

The efficacy of NeemAzal powder, two local neem (Azadirachta indica ) products [neem seed powder (NSP) and neem seed oil (NSO)], as well as a local Lamiaceae, Plectranthus glandulosus leaf powder, applied at four different rates for the control of Sitophilus zeamais was determined. Mortality was recorded 1, 3, 7 and 14 days after S. zeamais infestation, followed by the determination of F₁ progeny production. Grain damage, population increase and grain germination were assessed for treated grains that were stored for 4 months. Grains treated with P. glandulosus powder and NSP had relatively low mortality (5.0–22.5%) after 3 days whereas NeemAzal and NSO had higher mortality (55.0–98.8%). Maximum mortality of 99, 100, 96 and 74% were achieved for NeemAzal (12 g/kg after 14 days), NSO (4 ml/kg after 7 days), NSP (40 g/kg after 14 days) and P. glandulosus powder (40 g/kg, after 14 days), respectively. In the same order, 7-day LC₅₀ values were 0.02 g/kg, 1.46 ml/kg, 12.44 g/kg and 28.9 g/kg. The three neem products greatly reduced progeny emergence, while P. glandulosus powder was less effective. NeemAzal protected the grains against S. zeamais damage better than the local neem products, which in turn provided far better grain protection against the weevil damage than P. glandulosus powder. NeemAzal was superior to the local neem products in grain protection against germination loss, with P. glandulosus being the least effective. NeemAzal and NSO had sufficient efficacy to be a component of an integrated management package for S. zeamais.     

The behaviour of the species mingling index<Emphasis Type="Italic"> M</Emphasis><Subscript><Emphasis Type="Italic">sp</Emphasis></Subscript> in relation to species dominance and dispersion

Ecosystem conservation plays an increasingly important role in forest management. The value for such conservation has been directly linked to high diversity of species and structure within systems. In the past, forestry inventory practices have concentrated on aspects that were primarily required for timber management. Now, however, much interest has arisen in measures that will indicate higher or lower diversity. The interspersion of trees of different species reflects diversity at a local level and may serve as an important indicator for the simplification of a forest or woodland system. This article shows that the mingling index M_sp is robust in describing the spatial dispersion of plants; some guidelines for interpreting M_sp are provided.     

Allelopathic effects of <Emphasis Type="Italic">Eucalyptus urophylla</Emphasis> on ten tree species in south China

Aqueous leaf leachate and leaf volatile of Eucalyptus urophylla were used to investigate their effects on seed germination and seedling growth of seven native tree species (Cinnamomum burmanni, Cryptocarya concinna, Machilus chinensis, Photinia benthamiana, Pygeum topengii, Diospyros morrisiana and Pterospermum lanceaefolium) and three exotic tree species (Acacia confusa, Albizia lebbeck and Albizia falcataria). It was revealed that aqueous leaf leachate suppressed the seed germination and seedling growth of Photinia benthamiana, Pygeum topengii, Diospyros morrisiana and Pterospermum lanceaefolium. In case of Cryptocarya concinna, leaf leachate decreased only the seed germination. Leaf volatile concentration beyond 250 g per desiccator had a significant suppression effect on germination of Cinnamomum burmanni, Cryptocarya concinna, Machilus chinensis, Diospyros morrisiana and Pterospermum lanceaefolium. The seedlings growth for most species was affected at concentration of 50 g and above, with the exception of Cryptocarya concinna, Pygeum topengii and Albizia falcataria which were not obviously suppressed at 50 or 150 g leaf weight. However, the growth of Pterospermum lanceaefolium remained uninhibitory till when volatile at the concentration of 350 g leaf weight was applied. From the result it can be concluded that the allelochemical effects of the donor varies with the dose applied, and species respond differently to allelochemical released by the Eucalyptus.