Cashew tree has gradually moved from a purely ecological aspect to a socio-economic one, due to the marketing of its nuts. But production per area, estimated at between 424 and 547 kg/ha, remains low, in contrast to I...Cashew tree has gradually moved from a purely ecological aspect to a socio-economic one, due to the marketing of its nuts. But production per area, estimated at between 424 and 547 kg/ha, remains low, in contrast to India (2<sup>nd</sup> largest producer) and Vietnam (3<sup>rd</sup> largest producer), whose yields range from 1000 to 1500 and 2000 to 2500 kg/ha respectively. This low yield is due to a number of factors, among which insect pests are the most damaging. Among these insects, termites are considered to be one of the main pests of cashew trees. The general objective of this study is to contribute to termite management through the use of bioinsecticides, an alternative to the use of chemicals in cashew orchards. Five (5) biological products were tested: Limocide, Carapa oil, Neem oil, Kitana and Kaskara. Among them, two products proved effective, with a mortality rate of over 50%. These were Limocide, whose LC50 was obtained in 24 h at a dose of 3.6 g/ml and 3.1 g/ml , giving a mortality rate of 57.66% ± 4.04% and 51.33 ± 2.08 respectively , and Carapa, at a dose of 4.5 g/ml, with an estimated mortality rate of 52.33% ± 1.52%. Such results have demonstrated the potential application of Limocide and Carapa biopesticides to sustainably control termites in cashew orchards of Côte d’Ivoire.展开更多
We studied seed germination and seedling growth performance in an economically and socially important fruit tree species <em>Vitellaria paradoxa</em> C.F. Gaertn. subsp. <em>nilotica</em> (shea...We studied seed germination and seedling growth performance in an economically and socially important fruit tree species <em>Vitellaria paradoxa</em> C.F. Gaertn. subsp. <em>nilotica</em> (shea tree) in Uganda. The study aimed at determining variations in germination among five shea tree seed provenances and seedling growth performance based on five growth traits (total height, root collar diameter, leaf length, leaf width and leaf petiole length). Five populations were considered from four agroecological zones comprising of 180 candidate “plus” trees. The seed trees consisted of 16 ethnovarieties selected based on their traits for fast growth and high oil yield. A total of 1,204 biological seeds were collected and sown in a tree nursery at Ngetta Zonal Agricultural Research and Development Institute during the month of June 2018 in a randomized incomplete block design with three replications. Significant variation (χ = 708;p < 0.01) was observed in seedling phenotypic traits within and between populations. Regression equation for height growth and leaf size index were given as y = 0.3787 + 12.671x and y = 0.6483 + 15.413x respectively. Root collar diameter was more correlated to leaf size index (0.425) than to height growth (0.30). Clustering of shea tree seedlings based on phenotypic growth traits revealed one aggregated cluster indicating that most of the seedlings from the five populations were similar (Jaccard index 0.92, p < 0.01). However, clustering based on SNP markers revealed three different populations. We recorded higher growth (χ = 708;p < 0.001) in Arua shea population. Red seeded;thin pulped and hairy fruited shea tree ethnovarieties recorded faster growth than the rest. The results reveal useful traits in selection for tree growth and further identified shea tree ethnovarieties that could be selected for fast growth.展开更多
The increase in global climate change incidents is a glaring indication that more pragmatic and direct approaches to tree and forest management are urgently needed.A study was conducted around Mount Elgon Uganda betwe...The increase in global climate change incidents is a glaring indication that more pragmatic and direct approaches to tree and forest management are urgently needed.A study was conducted around Mount Elgon Uganda between June 2018 and December 2019.The objectives were to:i)determine the socio-economic characteristics of women and youth farmers engaged in agroforestry,ii)determine the relationship between women and youth farmers’characteristics in adoption of tree technologies and related decisions,and iii)assess the incentives,challenges and strategies for promoting agroforestry technologies’adoption in the region.Data were collected from 250 women and youths using focus group discussions,semi-structured,and key informant interviews.Results showed that engagements in agroforestry practices attracted largely(82%)of uneducated women and youths and basic methods and tools were used to farm.Up to 70%of women and youth relied on crop farming as a major source of income,earning about USD$250 perannum.Farm and family size were positively(P>0.0001)related to tree adoption decisions while farmer capacity building activities(such as training,farmer guided field tours,and participatory farmer trial’s establishments)and access to low-cost tree seedlings motivated their involvement in tree planting.Land scarcity,soil,water,and tree conservation issues and shortage of desired tree species affected the extent of tree growing in both women and youth-led households.The suggested strategies comprised strengthening farmer capacity-building programs and upholding soil and water conservation technologies.Agroforestry has the potential to address the challenges related to land scarcity and shortage of desired tree products in women and youth-led households around Mount Elgon.However,the women and youths involved in farming activities were generally poor,illiterate and faced issues of land insecurity.These factors,limited their full potential and interest in agroforestry.A significant increase in tree adoption rates by women and youths will be achieved with increased training on tree seed collection and pre-treatment,reforestation programs as well as tree pest and disease control.展开更多
Cymbopogon nardus is an invasive grass weed in the grazing lands of Uganda affecting growth of desirable species and impeding movement of livestock. Farmers have for long used manual removal with a hand hoe to control...Cymbopogon nardus is an invasive grass weed in the grazing lands of Uganda affecting growth of desirable species and impeding movement of livestock. Farmers have for long used manual removal with a hand hoe to control the weed to allow growth of palatable species. In order to reduce on the drudgery associated with the hand hoe, a trial was set up to evaluate removal with a hand hoe, use of fire and spraying the weed with glyphosate herbicide to control Cymbopogon nardus. Eight treatments associated with the different control strategies were replicated on four sites in the land use system. Both manual removal with a hand hoe and spraying with glyphosate herbicide were effective in controlling Cymbopogon nardus with 95% and 92% kill of Cymbopogon tussocks, respectively. The differences between the two control methods were not significant. Plant species biodiversity recovery was faster in the manually controlled plots than in those sprayed with glyphosate, but the number of species was not significantly different. The frequency of occurrence of species was however significantly different with manually controlled plots registering a higher frequency of the species. Fire had no effect as a control strategy, but instead increased the number of tussocks, growth vigour of the re-growth, flowering and hence seed setting. After three seasons, no significant difference was observed in species biodiversity between manual and herbicide control. These results suggest that herbicides could effectively be used to control Cymbopogon nardus to cut on costs and avoid the drudgery normally associated with manual control.展开更多
Erianthus species are perennial C4 grasses with such high biomass productivity and high tolerance to environmental stresses that they can be grown in marginal land to supply raw material for cellulosic bioethanol. Bec...Erianthus species are perennial C4 grasses with such high biomass productivity and high tolerance to environmental stresses that they can be grown in marginal land to supply raw material for cellulosic bioethanol. Because high biomass production and strong tolerance to environmental stresses might be based on their large and deep-root system, we closely examined the morphology and anatomy of roots in first-year seedlings of field-grown Erianthus arundinaceus. The deep-root system of E. arundinaceus consists of many nodal roots growing with steep growth angles. Diameter of nodal roots with large variations (0.5 - 5 mm) correlates with the size and number of large xylem vessels. The microscopic observation shows that the nodal roots with dense root hairs developed soil sheath, hypodermis with lignified sclerenchyma in the outer cortex, and aerenchyma in the mid-cortex. In addition, starch grains were densely accumulated in the stele of nodal roots in winter. In the first year, E. arundinaceus developed less lateral roots than other reported grass species. The lateral roots formed a large xylem vessel in the center of the stele and no hypodermis in the outer cortex. Morphology and anatomy of E. arundinaceus root were discussed with reference to strong tolerance to environmental stresses.展开更多
Post-harvest storage losses (PHLs) remain significant in Sub-Saharan Africa (SSA) due to several factors mainly insect pests and molds. Hermetic storage technologies (HSTs) are being promoted to address these storage ...Post-harvest storage losses (PHLs) remain significant in Sub-Saharan Africa (SSA) due to several factors mainly insect pests and molds. Hermetic storage technologies (HSTs) are being promoted to address these storage losses. In Uganda, HSTs were first introduced in 2012. However, its use among farming households remains low today. Data were collected from 306 smallholder farmers from four districts of Northern Uganda using a pre-tested semi-structured questionnaire to understand their knowledge, use, and constraints to the adoption of hermetic storage. A multivariate Logit regression model was used to find the significance of the factors affecting adoption. Results showed low awareness and use of hermetic storage among smallholder farmers. Only 53.3% of the interviewed farmers were aware of the use of hermetic storage for grain storage. The SuperGrain bag was the most known form of hermetic storage (35.3%), followed by the Purdue Improved Crop Storage (PICS) bag (34.9%), metallic silo (15.5%), and plastic silo (14.4%). Hermetic storage use was even lower as only 17.6% of the surveyed farmers were using one or more forms of hermetic storage to store their grains. Insect pest management without chemical insecticides was the main reason (83.1%) for hermetic storage use. About 75.5% of those aware of hermetic storage had received training in the technology. Hermetic storage use in farming households led to improved food availability, household income, and nutrition. Lack of local availability (50.2%), high costs (37.8%), and inadequate knowledge (6.9%) were the main constraints hindering the adoption of hermetic storage in Northern Uganda. The logit regression models showed that only training in hermetic storage significantly (p = 0.002) affected farmers’ decision to adopt hermetic storage. Understanding the factors that constrain the adoption of HSTs could provide policymakers with important information to initiate and design policies and programs aimed at reducing crop storage losses.展开更多
Côte d’Ivoire is the third largest supplier of mangoes to the European market, after Brazil and Peru, and the leading exporter of mangoes to the African market. However, mango production is faced with the proble...Côte d’Ivoire is the third largest supplier of mangoes to the European market, after Brazil and Peru, and the leading exporter of mangoes to the African market. However, mango production is faced with the problem of fruit flies, which cause yields to fall. In order to combat fruit flies, a study was launched into the early detection of fruit flies at different phenological stages of the mango tree. The overall aim of the study is to help improve mango productivity through early detection of fruit flies at different phenological stages. Accordingly, a trapping system containing sexual attractants and insecticides was set up in the four cardinal directions of the mango orchard. Insects were collected once a week during the vegetative, flowering, mango development and mango ripening stages. Twelve fruit fly species in four genera and seven species were identified, with a high abundance of Bactrocera dorsalis ((265.64 ± 132.82) individuals) and Ceratitis cosyra ((171.87 ± 85.94) individuals). Fruit flies were most abundant at the maturity stage, with a high abundance of Bactrocera dorsalis species ((129.20 ± 46.15) individuals) and at the vegetative stage ((597.80 ± 214.07) individuals), and a high abundance of Ceratitis cosyra species at the flowering (111.26 ± 33.71) and mango development ((187.47 ± 62.64) individuals) stages. In conclusion, the phenological stages of mango influence the population of fruit flies in mango orchards.展开更多
Climate change poses daunting challenges to agricultural production and food security.Rising temperatures,shifting weather patterns,and more frequent extreme events have already demonstrated their effects on local,reg...Climate change poses daunting challenges to agricultural production and food security.Rising temperatures,shifting weather patterns,and more frequent extreme events have already demonstrated their effects on local,regional,and global agricultural systems.Crop varieties that withstand climate-related stresses and are suitable for cultivation in innovative cropping systems will be crucial to maximize risk avoidance,productivity,and profitability under climate-changed environments.We surveyed 588 expert stakeholders to predict current and novel traits that may be essential for future pearl millet,sorghum,maize,groundnut,cowpea,and common bean varieties,particularly in sub-Saharan Africa.We then review the current progress and prospects for breeding three prioritized future-essential traits for each of these crops.Experts predict that most current breeding priorities will remain important,but that rates of genetic gain must increase to keep pace with climate challenges and consumer demands.Importantly,the predicted future-essential traits include innovative breeding targets that must also be prioritized;for example,(1)optimized rhizosphere microbiome,with benefits for P,N,and water use efficiency,(2)optimized performance across or in specific cropping systems,(3)lower nighttime respiration,(4)improved stover quality,and(5)increased early vigor.We further discuss cutting-edge tools and approaches to discover,validate,and incorporate novel genetic diversity from exotic germplasm into breeding populations with unprecedented precision,accuracy,and speed.We conclude that the greatest challenge to developing crop varieties to win the race between climate change and food security might be our innovativeness in defining and boldness to breed for the traits of tomorrow.展开更多
文摘Cashew tree has gradually moved from a purely ecological aspect to a socio-economic one, due to the marketing of its nuts. But production per area, estimated at between 424 and 547 kg/ha, remains low, in contrast to India (2<sup>nd</sup> largest producer) and Vietnam (3<sup>rd</sup> largest producer), whose yields range from 1000 to 1500 and 2000 to 2500 kg/ha respectively. This low yield is due to a number of factors, among which insect pests are the most damaging. Among these insects, termites are considered to be one of the main pests of cashew trees. The general objective of this study is to contribute to termite management through the use of bioinsecticides, an alternative to the use of chemicals in cashew orchards. Five (5) biological products were tested: Limocide, Carapa oil, Neem oil, Kitana and Kaskara. Among them, two products proved effective, with a mortality rate of over 50%. These were Limocide, whose LC50 was obtained in 24 h at a dose of 3.6 g/ml and 3.1 g/ml , giving a mortality rate of 57.66% ± 4.04% and 51.33 ± 2.08 respectively , and Carapa, at a dose of 4.5 g/ml, with an estimated mortality rate of 52.33% ± 1.52%. Such results have demonstrated the potential application of Limocide and Carapa biopesticides to sustainably control termites in cashew orchards of Côte d’Ivoire.
文摘We studied seed germination and seedling growth performance in an economically and socially important fruit tree species <em>Vitellaria paradoxa</em> C.F. Gaertn. subsp. <em>nilotica</em> (shea tree) in Uganda. The study aimed at determining variations in germination among five shea tree seed provenances and seedling growth performance based on five growth traits (total height, root collar diameter, leaf length, leaf width and leaf petiole length). Five populations were considered from four agroecological zones comprising of 180 candidate “plus” trees. The seed trees consisted of 16 ethnovarieties selected based on their traits for fast growth and high oil yield. A total of 1,204 biological seeds were collected and sown in a tree nursery at Ngetta Zonal Agricultural Research and Development Institute during the month of June 2018 in a randomized incomplete block design with three replications. Significant variation (χ = 708;p < 0.01) was observed in seedling phenotypic traits within and between populations. Regression equation for height growth and leaf size index were given as y = 0.3787 + 12.671x and y = 0.6483 + 15.413x respectively. Root collar diameter was more correlated to leaf size index (0.425) than to height growth (0.30). Clustering of shea tree seedlings based on phenotypic growth traits revealed one aggregated cluster indicating that most of the seedlings from the five populations were similar (Jaccard index 0.92, p < 0.01). However, clustering based on SNP markers revealed three different populations. We recorded higher growth (χ = 708;p < 0.001) in Arua shea population. Red seeded;thin pulped and hairy fruited shea tree ethnovarieties recorded faster growth than the rest. The results reveal useful traits in selection for tree growth and further identified shea tree ethnovarieties that could be selected for fast growth.
文摘The increase in global climate change incidents is a glaring indication that more pragmatic and direct approaches to tree and forest management are urgently needed.A study was conducted around Mount Elgon Uganda between June 2018 and December 2019.The objectives were to:i)determine the socio-economic characteristics of women and youth farmers engaged in agroforestry,ii)determine the relationship between women and youth farmers’characteristics in adoption of tree technologies and related decisions,and iii)assess the incentives,challenges and strategies for promoting agroforestry technologies’adoption in the region.Data were collected from 250 women and youths using focus group discussions,semi-structured,and key informant interviews.Results showed that engagements in agroforestry practices attracted largely(82%)of uneducated women and youths and basic methods and tools were used to farm.Up to 70%of women and youth relied on crop farming as a major source of income,earning about USD$250 perannum.Farm and family size were positively(P>0.0001)related to tree adoption decisions while farmer capacity building activities(such as training,farmer guided field tours,and participatory farmer trial’s establishments)and access to low-cost tree seedlings motivated their involvement in tree planting.Land scarcity,soil,water,and tree conservation issues and shortage of desired tree species affected the extent of tree growing in both women and youth-led households.The suggested strategies comprised strengthening farmer capacity-building programs and upholding soil and water conservation technologies.Agroforestry has the potential to address the challenges related to land scarcity and shortage of desired tree products in women and youth-led households around Mount Elgon.However,the women and youths involved in farming activities were generally poor,illiterate and faced issues of land insecurity.These factors,limited their full potential and interest in agroforestry.A significant increase in tree adoption rates by women and youths will be achieved with increased training on tree seed collection and pre-treatment,reforestation programs as well as tree pest and disease control.
文摘Cymbopogon nardus is an invasive grass weed in the grazing lands of Uganda affecting growth of desirable species and impeding movement of livestock. Farmers have for long used manual removal with a hand hoe to control the weed to allow growth of palatable species. In order to reduce on the drudgery associated with the hand hoe, a trial was set up to evaluate removal with a hand hoe, use of fire and spraying the weed with glyphosate herbicide to control Cymbopogon nardus. Eight treatments associated with the different control strategies were replicated on four sites in the land use system. Both manual removal with a hand hoe and spraying with glyphosate herbicide were effective in controlling Cymbopogon nardus with 95% and 92% kill of Cymbopogon tussocks, respectively. The differences between the two control methods were not significant. Plant species biodiversity recovery was faster in the manually controlled plots than in those sprayed with glyphosate, but the number of species was not significantly different. The frequency of occurrence of species was however significantly different with manually controlled plots registering a higher frequency of the species. Fire had no effect as a control strategy, but instead increased the number of tussocks, growth vigour of the re-growth, flowering and hence seed setting. After three seasons, no significant difference was observed in species biodiversity between manual and herbicide control. These results suggest that herbicides could effectively be used to control Cymbopogon nardus to cut on costs and avoid the drudgery normally associated with manual control.
文摘Erianthus species are perennial C4 grasses with such high biomass productivity and high tolerance to environmental stresses that they can be grown in marginal land to supply raw material for cellulosic bioethanol. Because high biomass production and strong tolerance to environmental stresses might be based on their large and deep-root system, we closely examined the morphology and anatomy of roots in first-year seedlings of field-grown Erianthus arundinaceus. The deep-root system of E. arundinaceus consists of many nodal roots growing with steep growth angles. Diameter of nodal roots with large variations (0.5 - 5 mm) correlates with the size and number of large xylem vessels. The microscopic observation shows that the nodal roots with dense root hairs developed soil sheath, hypodermis with lignified sclerenchyma in the outer cortex, and aerenchyma in the mid-cortex. In addition, starch grains were densely accumulated in the stele of nodal roots in winter. In the first year, E. arundinaceus developed less lateral roots than other reported grass species. The lateral roots formed a large xylem vessel in the center of the stele and no hypodermis in the outer cortex. Morphology and anatomy of E. arundinaceus root were discussed with reference to strong tolerance to environmental stresses.
文摘Post-harvest storage losses (PHLs) remain significant in Sub-Saharan Africa (SSA) due to several factors mainly insect pests and molds. Hermetic storage technologies (HSTs) are being promoted to address these storage losses. In Uganda, HSTs were first introduced in 2012. However, its use among farming households remains low today. Data were collected from 306 smallholder farmers from four districts of Northern Uganda using a pre-tested semi-structured questionnaire to understand their knowledge, use, and constraints to the adoption of hermetic storage. A multivariate Logit regression model was used to find the significance of the factors affecting adoption. Results showed low awareness and use of hermetic storage among smallholder farmers. Only 53.3% of the interviewed farmers were aware of the use of hermetic storage for grain storage. The SuperGrain bag was the most known form of hermetic storage (35.3%), followed by the Purdue Improved Crop Storage (PICS) bag (34.9%), metallic silo (15.5%), and plastic silo (14.4%). Hermetic storage use was even lower as only 17.6% of the surveyed farmers were using one or more forms of hermetic storage to store their grains. Insect pest management without chemical insecticides was the main reason (83.1%) for hermetic storage use. About 75.5% of those aware of hermetic storage had received training in the technology. Hermetic storage use in farming households led to improved food availability, household income, and nutrition. Lack of local availability (50.2%), high costs (37.8%), and inadequate knowledge (6.9%) were the main constraints hindering the adoption of hermetic storage in Northern Uganda. The logit regression models showed that only training in hermetic storage significantly (p = 0.002) affected farmers’ decision to adopt hermetic storage. Understanding the factors that constrain the adoption of HSTs could provide policymakers with important information to initiate and design policies and programs aimed at reducing crop storage losses.
文摘Côte d’Ivoire is the third largest supplier of mangoes to the European market, after Brazil and Peru, and the leading exporter of mangoes to the African market. However, mango production is faced with the problem of fruit flies, which cause yields to fall. In order to combat fruit flies, a study was launched into the early detection of fruit flies at different phenological stages of the mango tree. The overall aim of the study is to help improve mango productivity through early detection of fruit flies at different phenological stages. Accordingly, a trapping system containing sexual attractants and insecticides was set up in the four cardinal directions of the mango orchard. Insects were collected once a week during the vegetative, flowering, mango development and mango ripening stages. Twelve fruit fly species in four genera and seven species were identified, with a high abundance of Bactrocera dorsalis ((265.64 ± 132.82) individuals) and Ceratitis cosyra ((171.87 ± 85.94) individuals). Fruit flies were most abundant at the maturity stage, with a high abundance of Bactrocera dorsalis species ((129.20 ± 46.15) individuals) and at the vegetative stage ((597.80 ± 214.07) individuals), and a high abundance of Ceratitis cosyra species at the flowering (111.26 ± 33.71) and mango development ((187.47 ± 62.64) individuals) stages. In conclusion, the phenological stages of mango influence the population of fruit flies in mango orchards.
文摘Climate change poses daunting challenges to agricultural production and food security.Rising temperatures,shifting weather patterns,and more frequent extreme events have already demonstrated their effects on local,regional,and global agricultural systems.Crop varieties that withstand climate-related stresses and are suitable for cultivation in innovative cropping systems will be crucial to maximize risk avoidance,productivity,and profitability under climate-changed environments.We surveyed 588 expert stakeholders to predict current and novel traits that may be essential for future pearl millet,sorghum,maize,groundnut,cowpea,and common bean varieties,particularly in sub-Saharan Africa.We then review the current progress and prospects for breeding three prioritized future-essential traits for each of these crops.Experts predict that most current breeding priorities will remain important,but that rates of genetic gain must increase to keep pace with climate challenges and consumer demands.Importantly,the predicted future-essential traits include innovative breeding targets that must also be prioritized;for example,(1)optimized rhizosphere microbiome,with benefits for P,N,and water use efficiency,(2)optimized performance across or in specific cropping systems,(3)lower nighttime respiration,(4)improved stover quality,and(5)increased early vigor.We further discuss cutting-edge tools and approaches to discover,validate,and incorporate novel genetic diversity from exotic germplasm into breeding populations with unprecedented precision,accuracy,and speed.We conclude that the greatest challenge to developing crop varieties to win the race between climate change and food security might be our innovativeness in defining and boldness to breed for the traits of tomorrow.
