Developing appropriate control measures for the Mahogany shoot borer, Hypsipyla robusta Moore has become increasingly important due to the severe damaging effect of the pest on the establishment of the saplings of Swi...Developing appropriate control measures for the Mahogany shoot borer, Hypsipyla robusta Moore has become increasingly important due to the severe damaging effect of the pest on the establishment of the saplings of Swietenia mahagoni Jacq （Sapindales： Meliaceae）. Existing management methods are largely limited to silvicultural practices and spraying of chemical insecticides. To identify a potential fungal biocontrol agent, we compared the virulence of six native and two standard ARSEF isolates of Metarhizium anisopliae Metsch. against this pest. The average survival time and conidial yield of IWST-Ma7 was higher （6.2 to 7.3 days and 4.9 to 4.7 x 105 conidia/ml） than the standards. Sig- nificant difference in sporulation on the cadavers between isolates, doses and incubation periods were substantiated for the selection of potential strain. The mycotoxic effects of crude soluble protein extract when in- corporated in the artificial diet, the ARSEF 2596 and ARSEF 3603 showed LDs0 value of 3.7% and 5.6%. However, IWST-Ma7 was highly lethal with significant lowest LDs0 value of 2.6%. The enzyme activity of IWST-Ma7 was highest for chitinase, CDA, protease and lipase viz., 1.90 U/mg, 1.80 U/mg, 0.98 U/mg and 0.80 U/mg respectively. However the enzyme activity of chitinase and Chitin deacetylase assay for all the isolates was significantly higher than protease and lipase activity. The ITS regions （5.8S rDNA and 28S rDNA） of seven isolates of M. anisopliae were amplified using the ITS1 and ITS4 primers which was a unique fragment of approximately 550 bp. Based on ITS regions, phy- logenetic tree have been constructed and the isolates have been grouped in to 5 clades. The virulence and mycotoxic effects of different isolates could rationally be used to employ them for the management of the mahogany borer.展开更多
African mahogany, one of the world’s most valuable timber species is threatened by over-exploitation in natural forests and failure of plantations due to attacks by the shoot borer Hypsipyla robusta. Mixed-species pl...African mahogany, one of the world’s most valuable timber species is threatened by over-exploitation in natural forests and failure of plantations due to attacks by the shoot borer Hypsipyla robusta. Mixed-species plantations has been reported to be an effective component of integrated pest management of major pest in other crops;but there is very limited empirical data on its use for managing Hypsipyla in mahogany mixed stands in West Africa. The aim of this study was to assess the effect of mixed-species stands as management intervention, on the growth of Khaya grandifoliola and Khaya ivorensis in relation to Hypsipyla robusta attack in a 10 ha experimental plantation in the wet evergreen forest type in Ghana. Khaya grandifoliola recorded faster growth than Khaya ivorensis in this forest type though the later naturally grow in this forest type while the former is introduced from the dry forest. Two years after planting, diameter and height growth were greater in the mixed-species stand than the pure stands for K. grandifoliola and K. ivorensis. Hypsipyla damage was less in the mixed stands of both K. grandifoliola and K. ivorensis compared to the pure stands, with the 20% and 10% Khaya mixed stand recording the lowest attack in both species. It can be recommended that mixed stands of the two Khaya species at 20% or lower Khaya density might be ideal for reducing the levels of Hypsipyla attack in this type of forest.展开更多
An experimental study was carried out on bricks using local materials in order to take into account the waste wood management to protect the environment and to reduce the cost of the habitat. Chips and sawdust were bu...An experimental study was carried out on bricks using local materials in order to take into account the waste wood management to protect the environment and to reduce the cost of the habitat. Chips and sawdust were built-in clay bricks in order to study their influence on the compressive strength, Young’s modulus and the speed for soundproofing. Testings in compressive strength were made on the parallelepiped clay bricks, stabilized with different percentages of cement, with incorporation to various percentages of sawdust or wood chips (Mahogany), using a universal press. Young’s modulus was measured from the speed of sound by the ultrasonic method. The results obtained show that the incorporation of mahogany tree chips in the stabilized brick at 8% of cement, does not have much effect on the compressive strength. It was found that the incorporation of chips or sawdust on the clay brick, does not improve the compressive strength. The Young’s modulus decreases with increasing content of sawdust and practically remains constant regardless of the content of chips at 4% and 6% of cement. The clay brick mixed with 8% of mahogany sawdust can be an acoustic barrier.展开更多
The significant role of tropical forest ecosystems in the global carbon budget has increased the need for accurate estimates of tropical forest biomass.The lack of large-scale biomass allometric equations hampers the ...The significant role of tropical forest ecosystems in the global carbon budget has increased the need for accurate estimates of tropical forest biomass.The lack of large-scale biomass allometric equations hampers the understanding of the spatial distribution of tree biomass and carbon stocks and their influencing factors in West Africa.This study aimed to develop allometric equations to estimate aboveground biomass of African oak(Afzelia africana Sm.)in Burkina Faso and to analyze factors affecting the variability of tree biomass and carbon storage.Sixty individual trees were destructively sampled in four protected areas along two climatic zones.In each climatic zone,log–log models were tested and fitted to each aboveground biomass component and to the total aboveground biomass.Carbon content in tree aboveground components was evaluated using the ash method.All validated equations showed good fit and performance with high explained variance.Allometric equations differed between the Sudano-sahelian zone and the Sudanian zone,except for leaf biomass equations.Both biomass allocation and carbon content varied significantly between tree components but not between climatic zones.Carbon content in tree components followed the patterns of biomass allocation with branches accounting for the highest proportion.In the two climatic zones,carbon contents were 50.18–52.62%for leaves,54.78–54.94%for stems and 54.96–55.99%for branches.Dry biomass ranged from 509.05 to 765.56 kg tree^-1 at site level and from 620.21 to 624.48 kg tree^-1 along climatic zones.Carbon content varied from 53.90%in the Sudano-sahelian zone to 54.39%in the Sudanian zone.This study indicated that climate does not influence aboveground biomass production and carbon sequestration of Afzelia africana along the Sudanosahelian and the Sudanian climatic zones of Burkina Faso.Future studies on climate–growth relationships should contribute to better understanding climate effects on biomass production and carbon storage.展开更多
Khaya anthotheca is a hardwood species from Africa and recently introduced to Brazil. This species yields high-quality wood for diverse applications, but little has been done toward an effective propagation method for...Khaya anthotheca is a hardwood species from Africa and recently introduced to Brazil. This species yields high-quality wood for diverse applications, but little has been done toward an effective propagation method for large-scale production in nurseries. We evaluated the effects of different concentrations of macro and micronutrients（i.e., 100, 50 and 25% of the concentration of a referenced solution） combined with indole-3-butyric acid（IBA） at 0 and 2 g L-1 on the survival rate of mini-stumps and the survival and adventitious rooting of K. anthotheca mini-cuttings. The mini-stumps were grown from a source of seeds imported from Ghana, West Africa. The ministumps survived at a high rate（97%）. Consistently high shoot yields were obtained from the mini-stumps（average of 1.8 per mini-stump）. High survival percentage of minicuttings and adventitious rooting were observed when solutions with 100 and 50% of the nutrients concentration were combined with 2 g L-1 IBA. Histological sections analyzed through optical microscopy indicated the tissues from mini-cutting stems were juvenile, which might have stimulated adventitious rooting. These results have important implications for further work aimed at establishing propagation strategies for K. anthotheca, which are of prime importance for assisting breeding programs of this species.展开更多
African mahogany,Khaya grandifoliola C.DC.,is the most planted mahogany species in Brazil,and became the choice species when plantations of Brazilian mahogany,Swietenia macrophyla King became unsustainable due to thei...African mahogany,Khaya grandifoliola C.DC.,is the most planted mahogany species in Brazil,and became the choice species when plantations of Brazilian mahogany,Swietenia macrophyla King became unsustainable due to their susceptibility to the shoot borer Hypsipyla grandella Zeller.This study evaluated plantation growth and the occurrence of cankers associated with Ectomyelois muriscis Dyar larvae.Surveys recorded plantation volume,survival,and canker incidence of a plantation established in 2010 at 6 m×5.5 m spacing.Larvae were collected and reared on canker bark fragments until final adult stage.Cankers were frequently associated with Ectomyelois muriscis larvae.The average incidence of the moth(2.9%)was not a significant concern,however,an extreme incidence of 45%would indicate that management strategies should be developed.This is the first report of Ectomyelois muriscis attacking the bark of Khaya grandifoliola in the Cerrado biome.展开更多
Background: Recent projections expect that Vietnam will be affected most severely by climate change with higher temperatures, more precipitation and rising sea levels. Especially increased temperatures will worsen the...Background: Recent projections expect that Vietnam will be affected most severely by climate change with higher temperatures, more precipitation and rising sea levels. Especially increased temperatures will worsen the situations in cities, amplifying the urban heat island effect. Green infrastructures, i.e. urban trees are a common rtool to improve the urban micro-climate for humans. Vital and well growing trees provide greatest benefits such as evaporative cooling, shading, air filtering and carbon storage. However, urban tree growth is often negatively affected by urban growing conditions such as high soil sealing with compacted tree pits providing small growing spaces with limited water, nutrient and oxygen supply, further warm temperatures and high pollution emissions. This study analyzed the growth of urban and rural African mahogany(Khaya senegalensis(Desr.) A. Juss.) trees in the city of Hanoi, Vietnam and the effects of the surrounding climate conditions on tree growth.Results: The results showed that rural African mahogany trees grew better than trees situated in the city center, which is contrary to other results on tree growth of temperate and subtropical cities worldwide. Moreover tree growth was similar regardless of the time of growth. Other results regarding stem growth of African mahogany located in different areas of Hanoi(east, west, north, city center) revealed a better growth in the northern and western outskirts of the city compared to the growth of trees in the city center.Conclusion: African mahogany trees in the urban centers of Hanoi showed a decreased growth compared to rural trees,which was likely induced by a low ground-water level and high pollution rates. In view of climate change and global warming, the decreased tree growth in the city center may also affect tree service provision such as shading and cooling. Those climate mitigation solutions are strongly needed in areas severely affected by climate change and global warming such as Vietnam.展开更多
A field experiment on eco-friendly pest control in cucumber (Cucumis sativa L.) field was conducted at Rajshahi University during April, 2011 to June, 2011 with eight botanical pesticides prepared from the leaves and ...A field experiment on eco-friendly pest control in cucumber (Cucumis sativa L.) field was conducted at Rajshahi University during April, 2011 to June, 2011 with eight botanical pesticides prepared from the leaves and seeds of Bangladeshi plants. These botanicals are mahogany seeds, (Swietenia mahagoni), chirata leaves (Swertia chirata), jute seeds (Corchorus olitorius L.), garlic (Allium sativum L.), marigold leaves (Tagetes erecta) and carrot leaves (Daucus carota). One control treatment without botanicals was maintained during this experiment where only water was sprayed. Out of these botanicals, a less number of insect attacks on cucumber leaves (1.33 ± 0.19) were found in combined treatment of mahogany and chirata whereas a high number of insect attacks were observed in combined treatment of garlic and jute seed (5.89 ± 0.40) and control (4.66 ± 0.33). Individual application of chirata extract also showed good protection of cucumber leaves (1.67 ± 0.19) from insect attack. A smaller number of leaves perforations were found in the combined treatment of mahogany and chirata (3.44 ± 0.29) compared to control (14.22 ± 1.05). Chirata extract also showed good performance (4.00 ± 0.19) against leaves perforation of insect. Besides the pest control, botanical pesticides also have enormous effect on plant growth. The tallest cucumber plant was observed in the combined treatment of mahogany and chirata (469.00 ± 63.51 cm) and shortest in garlic treatment (84.56 ± 15.24 cm). The cucumber production was also high in combined treatment of mahogany and chirata (1863.33 ± 196.32 g) compared to control (1260.00 ± 501.63 g). From this study, it is found that combined application of mahogany and chirata extract not only showed good protection of cucumber plant from insect attack but also increased the cucumber production. Therefore, we conclude that farmers should use botanical pesticides from mahogany seeds and chirata leaves instead of toxic chemical insecticides for controlling pest in cucumber field.展开更多
文摘Developing appropriate control measures for the Mahogany shoot borer, Hypsipyla robusta Moore has become increasingly important due to the severe damaging effect of the pest on the establishment of the saplings of Swietenia mahagoni Jacq （Sapindales： Meliaceae）. Existing management methods are largely limited to silvicultural practices and spraying of chemical insecticides. To identify a potential fungal biocontrol agent, we compared the virulence of six native and two standard ARSEF isolates of Metarhizium anisopliae Metsch. against this pest. The average survival time and conidial yield of IWST-Ma7 was higher （6.2 to 7.3 days and 4.9 to 4.7 x 105 conidia/ml） than the standards. Sig- nificant difference in sporulation on the cadavers between isolates, doses and incubation periods were substantiated for the selection of potential strain. The mycotoxic effects of crude soluble protein extract when in- corporated in the artificial diet, the ARSEF 2596 and ARSEF 3603 showed LDs0 value of 3.7% and 5.6%. However, IWST-Ma7 was highly lethal with significant lowest LDs0 value of 2.6%. The enzyme activity of IWST-Ma7 was highest for chitinase, CDA, protease and lipase viz., 1.90 U/mg, 1.80 U/mg, 0.98 U/mg and 0.80 U/mg respectively. However the enzyme activity of chitinase and Chitin deacetylase assay for all the isolates was significantly higher than protease and lipase activity. The ITS regions （5.8S rDNA and 28S rDNA） of seven isolates of M. anisopliae were amplified using the ITS1 and ITS4 primers which was a unique fragment of approximately 550 bp. Based on ITS regions, phy- logenetic tree have been constructed and the isolates have been grouped in to 5 clades. The virulence and mycotoxic effects of different isolates could rationally be used to employ them for the management of the mahogany borer.
文摘African mahogany, one of the world’s most valuable timber species is threatened by over-exploitation in natural forests and failure of plantations due to attacks by the shoot borer Hypsipyla robusta. Mixed-species plantations has been reported to be an effective component of integrated pest management of major pest in other crops;but there is very limited empirical data on its use for managing Hypsipyla in mahogany mixed stands in West Africa. The aim of this study was to assess the effect of mixed-species stands as management intervention, on the growth of Khaya grandifoliola and Khaya ivorensis in relation to Hypsipyla robusta attack in a 10 ha experimental plantation in the wet evergreen forest type in Ghana. Khaya grandifoliola recorded faster growth than Khaya ivorensis in this forest type though the later naturally grow in this forest type while the former is introduced from the dry forest. Two years after planting, diameter and height growth were greater in the mixed-species stand than the pure stands for K. grandifoliola and K. ivorensis. Hypsipyla damage was less in the mixed stands of both K. grandifoliola and K. ivorensis compared to the pure stands, with the 20% and 10% Khaya mixed stand recording the lowest attack in both species. It can be recommended that mixed stands of the two Khaya species at 20% or lower Khaya density might be ideal for reducing the levels of Hypsipyla attack in this type of forest.
文摘An experimental study was carried out on bricks using local materials in order to take into account the waste wood management to protect the environment and to reduce the cost of the habitat. Chips and sawdust were built-in clay bricks in order to study their influence on the compressive strength, Young’s modulus and the speed for soundproofing. Testings in compressive strength were made on the parallelepiped clay bricks, stabilized with different percentages of cement, with incorporation to various percentages of sawdust or wood chips (Mahogany), using a universal press. Young’s modulus was measured from the speed of sound by the ultrasonic method. The results obtained show that the incorporation of mahogany tree chips in the stabilized brick at 8% of cement, does not have much effect on the compressive strength. It was found that the incorporation of chips or sawdust on the clay brick, does not improve the compressive strength. The Young’s modulus decreases with increasing content of sawdust and practically remains constant regardless of the content of chips at 4% and 6% of cement. The clay brick mixed with 8% of mahogany sawdust can be an acoustic barrier.
基金funded by the German Federal Ministry of Education and Research (BMBF) through the West African Science Service Centre on Climate Change and Adapted Land Use (WASCAL) program。
文摘The significant role of tropical forest ecosystems in the global carbon budget has increased the need for accurate estimates of tropical forest biomass.The lack of large-scale biomass allometric equations hampers the understanding of the spatial distribution of tree biomass and carbon stocks and their influencing factors in West Africa.This study aimed to develop allometric equations to estimate aboveground biomass of African oak(Afzelia africana Sm.)in Burkina Faso and to analyze factors affecting the variability of tree biomass and carbon storage.Sixty individual trees were destructively sampled in four protected areas along two climatic zones.In each climatic zone,log–log models were tested and fitted to each aboveground biomass component and to the total aboveground biomass.Carbon content in tree aboveground components was evaluated using the ash method.All validated equations showed good fit and performance with high explained variance.Allometric equations differed between the Sudano-sahelian zone and the Sudanian zone,except for leaf biomass equations.Both biomass allocation and carbon content varied significantly between tree components but not between climatic zones.Carbon content in tree components followed the patterns of biomass allocation with branches accounting for the highest proportion.In the two climatic zones,carbon contents were 50.18–52.62%for leaves,54.78–54.94%for stems and 54.96–55.99%for branches.Dry biomass ranged from 509.05 to 765.56 kg tree^-1 at site level and from 620.21 to 624.48 kg tree^-1 along climatic zones.Carbon content varied from 53.90%in the Sudano-sahelian zone to 54.39%in the Sudanian zone.This study indicated that climate does not influence aboveground biomass production and carbon sequestration of Afzelia africana along the Sudanosahelian and the Sudanian climatic zones of Burkina Faso.Future studies on climate–growth relationships should contribute to better understanding climate effects on biomass production and carbon storage.
基金supported by CNPq(National Council for Scientific and Technological Development,Brazil)CAPES(Coordination for the Improvement of Higher Level Personnel,Brazil)
文摘Khaya anthotheca is a hardwood species from Africa and recently introduced to Brazil. This species yields high-quality wood for diverse applications, but little has been done toward an effective propagation method for large-scale production in nurseries. We evaluated the effects of different concentrations of macro and micronutrients（i.e., 100, 50 and 25% of the concentration of a referenced solution） combined with indole-3-butyric acid（IBA） at 0 and 2 g L-1 on the survival rate of mini-stumps and the survival and adventitious rooting of K. anthotheca mini-cuttings. The mini-stumps were grown from a source of seeds imported from Ghana, West Africa. The ministumps survived at a high rate（97%）. Consistently high shoot yields were obtained from the mini-stumps（average of 1.8 per mini-stump）. High survival percentage of minicuttings and adventitious rooting were observed when solutions with 100 and 50% of the nutrients concentration were combined with 2 g L-1 IBA. Histological sections analyzed through optical microscopy indicated the tissues from mini-cutting stems were juvenile, which might have stimulated adventitious rooting. These results have important implications for further work aimed at establishing propagation strategies for K. anthotheca, which are of prime importance for assisting breeding programs of this species.
基金Universidade Federal de Uberlandia supported L.Coelho,A.R.T.Nascimento and J.C.Santos。
文摘African mahogany,Khaya grandifoliola C.DC.,is the most planted mahogany species in Brazil,and became the choice species when plantations of Brazilian mahogany,Swietenia macrophyla King became unsustainable due to their susceptibility to the shoot borer Hypsipyla grandella Zeller.This study evaluated plantation growth and the occurrence of cankers associated with Ectomyelois muriscis Dyar larvae.Surveys recorded plantation volume,survival,and canker incidence of a plantation established in 2010 at 6 m×5.5 m spacing.Larvae were collected and reared on canker bark fragments until final adult stage.Cankers were frequently associated with Ectomyelois muriscis larvae.The average incidence of the moth(2.9%)was not a significant concern,however,an extreme incidence of 45%would indicate that management strategies should be developed.This is the first report of Ectomyelois muriscis attacking the bark of Khaya grandifoliola in the Cerrado biome.
基金Funding Source:AUDI Environmental Foundation(project 5101954:"Reaktionskinetik von B(a|¨)umen unter Klimaver(a|¨)nderungen"-"Reaction kinetics of trees under climate change")
文摘Background: Recent projections expect that Vietnam will be affected most severely by climate change with higher temperatures, more precipitation and rising sea levels. Especially increased temperatures will worsen the situations in cities, amplifying the urban heat island effect. Green infrastructures, i.e. urban trees are a common rtool to improve the urban micro-climate for humans. Vital and well growing trees provide greatest benefits such as evaporative cooling, shading, air filtering and carbon storage. However, urban tree growth is often negatively affected by urban growing conditions such as high soil sealing with compacted tree pits providing small growing spaces with limited water, nutrient and oxygen supply, further warm temperatures and high pollution emissions. This study analyzed the growth of urban and rural African mahogany(Khaya senegalensis(Desr.) A. Juss.) trees in the city of Hanoi, Vietnam and the effects of the surrounding climate conditions on tree growth.Results: The results showed that rural African mahogany trees grew better than trees situated in the city center, which is contrary to other results on tree growth of temperate and subtropical cities worldwide. Moreover tree growth was similar regardless of the time of growth. Other results regarding stem growth of African mahogany located in different areas of Hanoi(east, west, north, city center) revealed a better growth in the northern and western outskirts of the city compared to the growth of trees in the city center.Conclusion: African mahogany trees in the urban centers of Hanoi showed a decreased growth compared to rural trees,which was likely induced by a low ground-water level and high pollution rates. In view of climate change and global warming, the decreased tree growth in the city center may also affect tree service provision such as shading and cooling. Those climate mitigation solutions are strongly needed in areas severely affected by climate change and global warming such as Vietnam.
文摘A field experiment on eco-friendly pest control in cucumber (Cucumis sativa L.) field was conducted at Rajshahi University during April, 2011 to June, 2011 with eight botanical pesticides prepared from the leaves and seeds of Bangladeshi plants. These botanicals are mahogany seeds, (Swietenia mahagoni), chirata leaves (Swertia chirata), jute seeds (Corchorus olitorius L.), garlic (Allium sativum L.), marigold leaves (Tagetes erecta) and carrot leaves (Daucus carota). One control treatment without botanicals was maintained during this experiment where only water was sprayed. Out of these botanicals, a less number of insect attacks on cucumber leaves (1.33 ± 0.19) were found in combined treatment of mahogany and chirata whereas a high number of insect attacks were observed in combined treatment of garlic and jute seed (5.89 ± 0.40) and control (4.66 ± 0.33). Individual application of chirata extract also showed good protection of cucumber leaves (1.67 ± 0.19) from insect attack. A smaller number of leaves perforations were found in the combined treatment of mahogany and chirata (3.44 ± 0.29) compared to control (14.22 ± 1.05). Chirata extract also showed good performance (4.00 ± 0.19) against leaves perforation of insect. Besides the pest control, botanical pesticides also have enormous effect on plant growth. The tallest cucumber plant was observed in the combined treatment of mahogany and chirata (469.00 ± 63.51 cm) and shortest in garlic treatment (84.56 ± 15.24 cm). The cucumber production was also high in combined treatment of mahogany and chirata (1863.33 ± 196.32 g) compared to control (1260.00 ± 501.63 g). From this study, it is found that combined application of mahogany and chirata extract not only showed good protection of cucumber plant from insect attack but also increased the cucumber production. Therefore, we conclude that farmers should use botanical pesticides from mahogany seeds and chirata leaves instead of toxic chemical insecticides for controlling pest in cucumber field.
