The Experts below are selected from a list of 12 Experts worldwide ranked by ideXlab platform
Leakey, Roger R.b. - One of the best experts on this subject based on the ideXlab platform.
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Domestication of indigenous fruit and nut trees for agroforestry in the Solomon Islands
Taylor & Francis, 2010Co-Authors: Pauku, Richard L., Lowe, Andrew J., Leakey, Roger R.b.Abstract:To counter deforestation and food insecurity, techniques to domesticate some of the culturally important indigenous nut tree species of Melanesia have been developed in the Solomon Islands. This process started with determining which species the local communities consider to be important. Barringtonia procera (Cutnut) and Inocarpus fagifer (Tahitian chestnut) were chosen as important model species fitting critical niches in the farming systems. The second step was to determine the factors which affect the rooting ability of cuttings of both species, to ensure that a robust and simple method was developed, appropriate for use by village communities on different islands. Both species were found to be easily propagated by juvenile, single-node, leafy, stem cuttings using a leaf area of 50cm2, 0.8% IBA as a rooting stimulant and forest/river soil as the rooting medium in a non-mist polythene propagator. This was supplemented by an attempt to induce physiological youth in the ontogenetically mature crowns of fruiting trees, so that early fruiting cultivars could be developed. While this was not entirely successful, the results provide pointers for future studies. The next step was to characterise the phenotypic variation for dry matter partitioning between different components of the nuts. This study found highly significant (P = 0.001) and continuous intraspecific variation in all the measured traits within each village population. This study was then complemented by a survey of molecular marker variation, which revealed significant genetic diversity within (87%) and between (13%) five surveyed populations of Barringtonia procera. Trees selected for their large kernels were found to be unrelated, so providing the opportunity to develop superior cultivars without severely narrowing intraspecific genetic diversity. Based on the above research, farmers in the Solomon Islands have been trained in tree domestication techniques and encouraged to select their best trees for domestication and planting on their own land. This approach towards participatory domestication is part of an initiative to develop an indigenous nut industry, with a focus on the processing and marketing of indigenous nuts, including the extraction of Canarium kernel oil
Roger R.b. Leakey - One of the best experts on this subject based on the ideXlab platform.
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Domestication of indigenous fruit and nut trees for agroforestry in the Solomon Islands.
Forests Trees and Livelihoods, 2010Co-Authors: Richard L. Pauku, Andrew J. Lowe, Roger R.b. LeakeyAbstract:In the Solomon Islands subsistence agriculture, monoculture plantations, new settlements and commercial timber extraction have resulted in indiscriminate deforestation. Agroforestry is an approach to sustainable landuse aimed at reversing these land degradation processes worldwide. In recent years, the domestication of indigenous fruit and nut trees has been added to the package of techniques making agroforestry more effective. By improving the livelihood benefits derived from agroforestry, the domestication of agroforestry trees is becoming a tool for the alleviation of the severe ecological and socio-economic problems of many developing countries. This thesis describes research to develop techniques for the domestication of indigenous nut tree species in the Solomon Islands. The first step was to determine which species the local communities considered to be their top priorities for domestication. Consequently, participatory surveys were undertaken in 155 households from five villages (Ringi, Seusepe, Rei, Poporo and Hunda) around Kolombangara Island. These surveys identified that Barringtonia procera (Cutnut) and Inocarpus fagifer (Tahitian chestnut) were the species that were most important as a source of food and income, while also filling in critical niches in the farming systems. A review of the literature found that very little is known about the biology of either species and that no previous studies had been done to domesticate these species. Farmers, however, confirmed that they were growing seeds from trees with desirable nut characters. The next step was to quantitatively characterise the phenotypic variation in the dry matter partitioning between different components of fruits and nuts from the five target villages. Whenever possible, 24 fruits were collected from each of 119 trees of B. procera and separated into their components (pulp, nut and kernel) for measurement. Within each population, highly significant (P= 0.001) and continuous intraspecific variation was found in all the measured traits. However, site-to-site variability was not significant. This quantitative data was also used to: (i) identify the market-oriented traits which could be combined to describe the 'ideal tree' or 'ideotype', in which 'Harvest Index' is maximised through the partitioning of dry matter to the commercially and domestically important kernel, (ii) identify the elite trees, which could be vegetatively propagated and (iii) ascertain through an anlaysis of the frequency distribution of the data, the degree to which farmers have already from their own actions initiated the domestication process. This study was complemented by a molecular study of genetic variation in each population. This molecular study found significant genetic diversity within and between the five populations of Barringtonia procera. It was also used in parallel with the morphological data, to evaluate: (i) the relatedness of three edible species of Barringtonia, and (ii) the relatedness of elite trees within the five populations. The results imply that the field collections failed to accurately distinguish the different species because of overlapping morphological characteristics. There was no conclusive evidence of any hybridisation between these species, it was clear that elite trees were generally unrelated. Further studies are required to elucidate the taxonomy of the three species. The final section of this thesis examined the factors which affect the rooting ability of both B. procera and I. fagifer stem cuttings. These results are then used to define the most appropriate material and techniques for the development of robust vegetative propagation protocols for village scale nurseries. Both species were found to be easily propagated by single-node, leafy, stem cuttings. Seventeen experiments tested the main factors known to affect the rooting of tropical tree cuttings. It was found that auxin (indole-3-butyric acid) did not significantly increase the rooting percentage, although there were significant differences in the numbers of roots formed, which in both species were maximal with 0.8% IBA. There were no consistent significant differences between cuttings from different nodes. However, the presence of a leaf was essential for rooting with 100% mortality in leafless cuttings of I. fagifer and 79 % mortality in B. procera. Both species, regardless of leaf area, leafy cuttings had 77-100% rooting success. Having identified the optimal treatments for stem cuttings from juvenile trees, the study progressed to an examination of one of the major constraints to developing cultivars from mature trees of any species, namely how to root cuttings taken from the mature (ontogenetically-mature) crown. Three approaches were examined:- (i) a comparison of the rooting ability of juvenile seedlings and shoots from potted mature marcots; (ii) a study of the factors affecting the successfulness of marcotting (air-layering) and (iii) the separation of physiological and ontogenetic ageing in the intact tree crown. In B. procera, juvenile cuttings from seedlings rooted better than cuttings from mature potted marcots, because the latter suffered leaf abscission. In I. fagifer mature and juvenile cuttings both rooted well. Shading mature stockplants of B. procera, however, significantly improved rooting ability of mature cuttings. Marcots of both species rooted 100% and a few factors were found to reduce this, although survival of the marcots declined if they were not harvested within 3-4 months. Attempts to separate ontogenetic and physiological ageing within the mature crown were partially successful, resulting in shoots which were comparable morphologically. However, enhanced rooting percentages were not consistently achieved across all treated shoots. Nevertheless, the number of roots per rooted cutting was significantly increased in the treated mature shoots. Marcotting resulted in establishment of mature stockplants in the nursery, which can be used in future as the source of mature cuttings for further work to develop cultivars from selected elite individuals. In conclusion, this study has developed robust and simple techniques which are appropriate for the domestication of B. procera and I. fagifer in remote communities in the Pacific, like Kolombangara Island. This opens the way for a programme of participatory domestication for these indigenous nuts in the Solomon Islands. This should greatly enhance the opportunities to commercialise indigenous nuts and to use them as a means to enhance income generation and to improve the livelihoods of rural people, as well as to develop more sustainable agricultural production systems based on agroforestry.
Pauku, Richard Larry - One of the best experts on this subject based on the ideXlab platform.
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Domestication of indigenous fruit and nut trees for agroforestry in Solomon Islands
2005Co-Authors: Pauku, Richard LarryAbstract:In the Solomon Islands subsistence agriculture, monoculture plantations, new settlements and commercial timber extraction have resulted in indiscriminate deforestation. Agroforestry is an approach to sustainable landuse aimed at reversing these land degradation processes worldwide. In recent years, the domestication of indigenous fruit and nut trees has been added to the package of techniques making agroforestry more effective. By improving the livelihood benefits derived from agroforestry, the domestication of agroforestry trees is becoming a tool for the alleviation of the severe ecological and socio-economic problems of many developing countries.\ud \ud This thesis describes research to develop techniques for the domestication of indigenous nut tree species in the Solomon Islands. The first step was to determine which species the local communities considered to be their top priorities for domestication. Consequently, participatory surveys were undertaken in 155 households from five villages (Ringi, Seusepe, Rei, Poporo and Hunda) around Kolombangara Island. These surveys identified that Barringtonia procera (Cutnut) and Inocarpus fagifer (Tahitian chestnut) were the species that were most important as a source of food and income, while also filling in critical niches in the farming systems. A review of the literature found that very little is known about the biology of either species and that no previous studies had been done to domesticate these species. Farmers, however, confirmed that they were growing seeds from trees with desirable nut characters.\ud \ud The next step was to quantitatively characterise the phenotypic variation in the dry matter partitioning between different components of fruits and nuts from the five target villages. Whenever possible, 24 fruits were collected from each of 119 trees of B. procera and separated into their components (pulp, nut and kernel) for measurement. Within each population, highly significant (P= 0.001) and continuous intraspecific variation was found in all the measured traits. However, site-to-site variability was not significant. This quantitative data was also used to: (i) identify the market-oriented traits which could be combined to describe the 'ideal tree' or 'ideotype', in which 'Harvest Index' is maximised through the partitioning of dry matter to the commercially and domestically important kernel, (ii) identify the elite trees, which could be vegetatively propagated and (iii) ascertain through an anlaysis of the frequency distribution of the data, the degree to which farmers have already from their own actions initiated the domestication process.\ud \ud This study was complemented by a molecular study of genetic variation in each population. This molecular study found significant genetic diversity within and between the five populations of Barringtonia procera. It was also used in parallel with the morphological data, to evaluate: (i) the relatedness of three edible species of Barringtonia, and (ii) the relatedness of elite trees within the five populations. The results imply that the field collections failed to accurately distinguish the different species because of overlapping morphological characteristics. There was no conclusive evidence of any hybridisation between these species, it was clear that elite trees were generally unrelated. Further studies are required to elucidate the taxonomy of the three species.\ud \ud The final section of this thesis examined the factors which affect the rooting ability of both B. procera and I. fagifer stem cuttings. These results are then used to define the most appropriate material and techniques for the development of robust vegetative propagation protocols for village scale nurseries. Both species were found to be easily propagated by single-node, leafy, stem cuttings. Seventeen experiments tested the main factors known to affect the rooting of tropical tree cuttings. It was found that auxin (indole-3-butyric acid) did not significantly increase the rooting percentage, although there were significant differences in the numbers of roots formed, which in both species were maximal with 0.8% IBA. There were no consistent significant differences between cuttings from different nodes. However, the presence of a leaf was essential for rooting with 100% mortality in leafless cuttings of I. fagifer and 79 % mortality in B. procera. Both species, regardless of leaf area, leafy cuttings had 77-100% rooting success.\ud \ud Having identified the optimal treatments for stem cuttings from juvenile trees, the study progressed to an examination of one of the major constraints to developing cultivars from mature trees of any species, namely how to root cuttings taken from the mature (ontogenetically-mature) crown. Three approaches were examined:- (i) a comparison of the rooting ability of juvenile seedlings and shoots from potted mature marcots; (ii) a study of the factors affecting the successfulness of marcotting (air-layering) and (iii) the separation of physiological and ontogenetic ageing in the intact tree crown. In B. procera, juvenile cuttings from seedlings rooted better than cuttings from mature potted marcots, because the latter suffered leaf abscission. In I. fagifer mature and juvenile cuttings both rooted well. Shading mature stockplants of B. procera, however, significantly improved rooting ability of mature cuttings. Marcots of both species rooted 100% and a few factors were found to reduce this, although survival of the marcots declined if they were not harvested within 3-4 months. Attempts to separate ontogenetic and physiological ageing within the mature crown were partially successful, resulting in shoots which were comparable morphologically. However, enhanced rooting percentages were not consistently achieved across all treated shoots. Nevertheless, the number of roots per rooted cutting was significantly increased in the treated mature shoots. \ud \ud Marcotting resulted in establishment of mature stockplants in the nursery, which can be used in future as the source of mature cuttings for further work to develop cultivars from selected elite individuals. \ud \ud In conclusion, this study has developed robust and simple techniques which are appropriate for the domestication of B. procera and I. fagifer in remote communities in the Pacific, like Kolombangara Island. This opens the way for a programme of participatory domestication for these indigenous nuts in the Solomon Islands. This should greatly enhance the opportunities to commercialise indigenous nuts and to use them as a means to enhance income generation and to improve the livelihoods of rural people, as well as to develop more sustainable agricultural production systems based on agroforestry
Pauku, Richard L. - One of the best experts on this subject based on the ideXlab platform.
-
Domestication of indigenous fruit and nut trees for agroforestry in the Solomon Islands
Taylor & Francis, 2010Co-Authors: Pauku, Richard L., Lowe, Andrew J., Leakey, Roger R.b.Abstract:To counter deforestation and food insecurity, techniques to domesticate some of the culturally important indigenous nut tree species of Melanesia have been developed in the Solomon Islands. This process started with determining which species the local communities consider to be important. Barringtonia procera (Cutnut) and Inocarpus fagifer (Tahitian chestnut) were chosen as important model species fitting critical niches in the farming systems. The second step was to determine the factors which affect the rooting ability of cuttings of both species, to ensure that a robust and simple method was developed, appropriate for use by village communities on different islands. Both species were found to be easily propagated by juvenile, single-node, leafy, stem cuttings using a leaf area of 50cm2, 0.8% IBA as a rooting stimulant and forest/river soil as the rooting medium in a non-mist polythene propagator. This was supplemented by an attempt to induce physiological youth in the ontogenetically mature crowns of fruiting trees, so that early fruiting cultivars could be developed. While this was not entirely successful, the results provide pointers for future studies. The next step was to characterise the phenotypic variation for dry matter partitioning between different components of the nuts. This study found highly significant (P = 0.001) and continuous intraspecific variation in all the measured traits within each village population. This study was then complemented by a survey of molecular marker variation, which revealed significant genetic diversity within (87%) and between (13%) five surveyed populations of Barringtonia procera. Trees selected for their large kernels were found to be unrelated, so providing the opportunity to develop superior cultivars without severely narrowing intraspecific genetic diversity. Based on the above research, farmers in the Solomon Islands have been trained in tree domestication techniques and encouraged to select their best trees for domestication and planting on their own land. This approach towards participatory domestication is part of an initiative to develop an indigenous nut industry, with a focus on the processing and marketing of indigenous nuts, including the extraction of Canarium kernel oil
Richard L. Pauku - One of the best experts on this subject based on the ideXlab platform.
-
Domestication of indigenous fruit and nut trees for agroforestry in the Solomon Islands.
Forests Trees and Livelihoods, 2010Co-Authors: Richard L. Pauku, Andrew J. Lowe, Roger R.b. LeakeyAbstract:In the Solomon Islands subsistence agriculture, monoculture plantations, new settlements and commercial timber extraction have resulted in indiscriminate deforestation. Agroforestry is an approach to sustainable landuse aimed at reversing these land degradation processes worldwide. In recent years, the domestication of indigenous fruit and nut trees has been added to the package of techniques making agroforestry more effective. By improving the livelihood benefits derived from agroforestry, the domestication of agroforestry trees is becoming a tool for the alleviation of the severe ecological and socio-economic problems of many developing countries. This thesis describes research to develop techniques for the domestication of indigenous nut tree species in the Solomon Islands. The first step was to determine which species the local communities considered to be their top priorities for domestication. Consequently, participatory surveys were undertaken in 155 households from five villages (Ringi, Seusepe, Rei, Poporo and Hunda) around Kolombangara Island. These surveys identified that Barringtonia procera (Cutnut) and Inocarpus fagifer (Tahitian chestnut) were the species that were most important as a source of food and income, while also filling in critical niches in the farming systems. A review of the literature found that very little is known about the biology of either species and that no previous studies had been done to domesticate these species. Farmers, however, confirmed that they were growing seeds from trees with desirable nut characters. The next step was to quantitatively characterise the phenotypic variation in the dry matter partitioning between different components of fruits and nuts from the five target villages. Whenever possible, 24 fruits were collected from each of 119 trees of B. procera and separated into their components (pulp, nut and kernel) for measurement. Within each population, highly significant (P= 0.001) and continuous intraspecific variation was found in all the measured traits. However, site-to-site variability was not significant. This quantitative data was also used to: (i) identify the market-oriented traits which could be combined to describe the 'ideal tree' or 'ideotype', in which 'Harvest Index' is maximised through the partitioning of dry matter to the commercially and domestically important kernel, (ii) identify the elite trees, which could be vegetatively propagated and (iii) ascertain through an anlaysis of the frequency distribution of the data, the degree to which farmers have already from their own actions initiated the domestication process. This study was complemented by a molecular study of genetic variation in each population. This molecular study found significant genetic diversity within and between the five populations of Barringtonia procera. It was also used in parallel with the morphological data, to evaluate: (i) the relatedness of three edible species of Barringtonia, and (ii) the relatedness of elite trees within the five populations. The results imply that the field collections failed to accurately distinguish the different species because of overlapping morphological characteristics. There was no conclusive evidence of any hybridisation between these species, it was clear that elite trees were generally unrelated. Further studies are required to elucidate the taxonomy of the three species. The final section of this thesis examined the factors which affect the rooting ability of both B. procera and I. fagifer stem cuttings. These results are then used to define the most appropriate material and techniques for the development of robust vegetative propagation protocols for village scale nurseries. Both species were found to be easily propagated by single-node, leafy, stem cuttings. Seventeen experiments tested the main factors known to affect the rooting of tropical tree cuttings. It was found that auxin (indole-3-butyric acid) did not significantly increase the rooting percentage, although there were significant differences in the numbers of roots formed, which in both species were maximal with 0.8% IBA. There were no consistent significant differences between cuttings from different nodes. However, the presence of a leaf was essential for rooting with 100% mortality in leafless cuttings of I. fagifer and 79 % mortality in B. procera. Both species, regardless of leaf area, leafy cuttings had 77-100% rooting success. Having identified the optimal treatments for stem cuttings from juvenile trees, the study progressed to an examination of one of the major constraints to developing cultivars from mature trees of any species, namely how to root cuttings taken from the mature (ontogenetically-mature) crown. Three approaches were examined:- (i) a comparison of the rooting ability of juvenile seedlings and shoots from potted mature marcots; (ii) a study of the factors affecting the successfulness of marcotting (air-layering) and (iii) the separation of physiological and ontogenetic ageing in the intact tree crown. In B. procera, juvenile cuttings from seedlings rooted better than cuttings from mature potted marcots, because the latter suffered leaf abscission. In I. fagifer mature and juvenile cuttings both rooted well. Shading mature stockplants of B. procera, however, significantly improved rooting ability of mature cuttings. Marcots of both species rooted 100% and a few factors were found to reduce this, although survival of the marcots declined if they were not harvested within 3-4 months. Attempts to separate ontogenetic and physiological ageing within the mature crown were partially successful, resulting in shoots which were comparable morphologically. However, enhanced rooting percentages were not consistently achieved across all treated shoots. Nevertheless, the number of roots per rooted cutting was significantly increased in the treated mature shoots. Marcotting resulted in establishment of mature stockplants in the nursery, which can be used in future as the source of mature cuttings for further work to develop cultivars from selected elite individuals. In conclusion, this study has developed robust and simple techniques which are appropriate for the domestication of B. procera and I. fagifer in remote communities in the Pacific, like Kolombangara Island. This opens the way for a programme of participatory domestication for these indigenous nuts in the Solomon Islands. This should greatly enhance the opportunities to commercialise indigenous nuts and to use them as a means to enhance income generation and to improve the livelihoods of rural people, as well as to develop more sustainable agricultural production systems based on agroforestry.
