Dataverse World Agroforestry (ICRAF)
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Evaluation de l’aptitude au marcottage aérien de Dacryodes edulis (g.don) lam. (Burseraceae) a maturation tardive dans le Mbam et Inoubou - Cameroun
No full textDacryodes edulis à maturation tardive est une espèce forestière ayant des valeurs aussi bien sur le plan économique que social, mais l’on déplore sa faible densité et le vieillissement des individus déjà existants. Jusqu'à ce jour, de nombreuses avancées ont été faites sur les techniques de multiplication végétatives mais les safoutiers "contre saison" n’ont pas fait l’objet de beaucoup d’étude
s. La quinzaine de mai 2010, à Makénéné, une série d’essai fut conduite dans les champs des paysans afin d’évaluer l’aptitude au marcottage aérien de cet individu sur trois facteurs dont le diamètre de la branche (les classes [2- 3[cm et [4 -5 [cm), l’orientation de la branche (orthotrope, oblique et plagiotrope) et le substrat d’enracinement (la fleur mâle de palmier à huile, le mélange terre noire/sable à proportion égale et la sciure de bois décomposé). 240 marcottes ont été posées sur 30 arbres, dont 10 arbres pour chaque facteur ; soit 60 marcottes au total pour l’essai diamètre et 90 pour chacun des essais orientation et substrat. Il ressort de ces travaux que l’enracinement des marcottes de Dacryodes edulis à maturation tardive est précoce (12,91 % à trois mois) pour des arbres âgés (plus de 15 ans) et la répartition des racines primaires autour de la marcotte est indépendante des traitements appliqués. De plus, à 5 mois, le pourcentage d’enracinement des marcottes n’a pas un effet significatif (p= 0,613) pour les branches de classes [2- 3[cm (56,67 ± 4,617%) et [4 -5 [cm (60,00 ± 4,634%) ; cependant, les branches de diamètre 2 à 3 cm favorisent le développement d’un nombre élevé de racines primaires et entrainent une grande mortalité des marcottes. L’orientation de la branche influence significativement l’enracinement des marcottes (p=0,039) ; la mieux adaptée est celle des branches plagiotropes, bien qu’elle présente une mortalité élevée (26,67 ± 4,74%) et un bas nombre de racines primaires (7,95 ± 0,93%). Les marcottes à la sciure ont le grand pourcentage d’enracinement (36,67 ± 4,32%) ; toute fois les marcottes au mélange terre noire/sable présentent le plus grand nombre de racines (15,47 ± 1,45%). L’on peut donc conclure que l’âge des arbres peut accélérer le processus d’enracinement des marcottes de D. edulis à maturation tardive. Pour le marcottage aérien des safoutiers les branches de gros diamètre, les branches plagiotropes et la sciure de bois décomposé sont certains éléments favorisant un enracinement optimal des marcottes
Analyse de la chaîne de valeurs des produits agroforestiers: cas du Safou (Dacryodes edulis) dans le Bas-congo et à Kinshasa en RDC
No full textCette étude de la chaîne de valeur de safou a été menée pour corriger les écarts existants entre les acteurs de la filière safou dans la province du Bas-Congo et de Kinshasa. Pour ce faire, des enquêtes ont été faites en 2010 auprès de 63 producteurs, 105 commerçants, 72 consommateurs et les données secondaires ont été obtenus à partir des observations personnelles dans la zone d’étude. Le prix moyen (période d’abondance) et (période de rareté) de vente de la caisse du safou est respectivement de 22 548,4 FC et de 27 451,6 FC. Le coût de revient est respectivement de 6 748 FC et 10 000 FC. Les marges nettes sont respectivement de 20 703,6 FC et 15 800,4 FC par caisse soit 23,60 et 24,15 $ USD pour les producteurs-vendeurs du Bas-Congo
Climate change perceptions and adaptations of rural households in Western Kenya
No full textThe ICRAF contribution was to collect and analyse data from Kenya as part of a four country study on climate change perceptions and responses by rural communities and farmers. The formal survey was done in Bondo and Bungoma districts. The study found that farmers were undertake a range of different ex ante and ex post measures in response to various drivers and incentives. SLM type of investments were made to varying degrees but often not in direct response to climate change or variability. Nonetheless, it was generally found that yield variability is reduced when SLM investments were made
Impact of fodder shrubs in East Africa
No full textThe objective of this study is twofold, to demonstrate (1) the effects of fodder shrubs on milk production and their value at the household and regional level and (2) the contribution of research by the World Agroforestry Centre toward strengthening the impact of fodder shrubs. The study is a synthesis of previous studies related to dissemination, adoption and impact combined with two new analyses, one quantitatively measuring the impact of the shrubs through econometric analysis and the other a qualitative analysis to better understand constraints on adoption and gender issues related to participation and control of benefits from fodder shrubs. Among the study findings are that fodder shrubs have been widely adopted in East Africa, by an estimated 205,000 smallholder dairy farmers by 2005. Women were active in planting shrubs, as monitoring found almost half of planters to be women. Several studies have confirmed that shrubs do have an impact on milk production. While feeding trials have found that 1 kilogram of calliandra increases milk production by 0.6–0.8 kilograms, a new survey of f
armers’ perceptions in Kenya found the effect to be about half as large after controlling for the effects of breeds, season and other feeds. Whether the effect is the lower or higher estimate, the overall impact of the shrubs in terms of additional net income from milk is high, at US29.6 million in Kenya alone over the past 15 years
Replication data for: Reproductive biology and characterization of Allanblackia parviflora A. Chev. in Ghana
No full textAllanblackia parviflora A. Chev. (Clusiaceae Lindley) is an indigenous tree species which is found in the rain forest regions of Ghana. It is a potential candidate fruit tree species being introduced in agroforestry systems. Information on genetic diversity, reproductive biology and fruit yield are not known. Field expeditions to seven populations of Allanblackia parviflora in Ghana were undertaken in 2003 to 2006 during which fruits were collected from 109 trees for characterization. The species was found to be dioecious. The colour of flowers varied from whitish to reddish. No ecological differences in number of fruits per tree, fruit shape and seed health were observed. However, large variations in fruit size and shape were observed among individual trees sample
CAFNET Local knowledge studies of trees in coffee systems in East Africa
No full textCAFNET research has elicited local agro-ecological knowledge from coffee growing areas within the vicinity of forest reserves in Kenya, Uganda and Rwanda. Knowledge was acquired from over 200 farmers in a stratified purposive sample, using a knowledge based systems approach. Ranking and phenology survey Building on the local knowledge studies and on-farm tree inventories, we designed a ranking and phenology survey to be applied across the 100 farms in the three counties to test consistency of farmer knowledge about physical attributes and phenology of trees found in coffee plots and along coffee plot boundaries
Replication data for: Allanblackia floribunda: a new oil tree crop for africa: amenability to grafting
No full textThree Allanblackia species (A. floribunda, A. stuhlmannii and A. parviflora) with high nutritive, medicinal, cosmetic and economic values are currently being domesticated as new oil tree crops. Allanblackia seeds contain a hard white fat consisting mostly of stearic (52 Â58%) and oleic (39 Â49%) acids. This unusual fatty acid content has the right properties for many different food and cosmetic products making them commercially interesting. Vegetative propagation studies on A. floribunda, which grows naturally in the moist forest of Cameroon and Nigeria, were initiated aimed at evaluating its amenability to grafting. Scions were grafted onto 18 month old rootstocks of A. floribunda using side tongue, top cleft, side veneer, whip-and-tongue methods under nursery conditions in Cameroon. In parallel, side tongue and inverted budding methods were also tested in situ on young A. floribunda wildings growing under semi-deciduous and evergreen tree covers. In addition, the effects of protecting side tongue new grafts with non perforated translucent plastic, perforated translucent plastic and aluminium foil were assessed. Under nursery conditions, side tongue grafts were significantly more successful (80.0 ± 6.3%), than grafts of side veneer (52.5 ± 7.9%), top cleft (55.0 ± 7.9%) and whip and tongue (50.0 ± 7.9%). The success of side tongue graft was further increased (86.7 ± 6.2%) under the shade of evergreen trees when protected by non perforated translucent plastic. These results indicate the potential for in situ grafting and top working to promote cultivation of more productive germplasm of Allanblackia within multifunctional agricultural systems
Fertilizer use patterns in Yunnan Province, China: Implications for agricultural and environmental policy
No full textBalancing the need to increase crop yields with the need to reduce the environmental impacts of fertilizers will pose major policy, regulatory, and extension challenges for China. A growing number of studies have demonstrated the potential for improving fertilizer use efficiency in China, but it is not clear how to achieve these efficiency improvements on a larger
scale. The empirical foundation for fertilizer policy in China is still weak, particularly in inland provinces. This paper examines fertilizer use patterns in Yunnan Province, an inland and ecologically important province in Southwest China, drawing on two household surveys. We find that fertilizer application rates in the survey areas are highly heterogeneous, among crops, households, and regions. Managing this diversity poses the largest challenge to fertilizer policy in Yunnan and, by extension, in China. None of the factors that we examine in this study are robust predictors of fertilizer intensity (kg ha-1) in the survey regions, though in one survey there is a strong inverse relationship between farm size and fertilizer intensity. The lack of clearer signals in the survey data, a consequence of heterogeneity in cropping patterns, agroecosystems, and local economies, underscores the importance of locally tailored approaches to fertilizer regulation in China, and of a strong, service-oriented agricultural extension system oriented around sustainable agriculture
Replication data for: The "model farmer" extension approach revisited: Are expert farmers effective innovators and disseminators?
No full textHow farmers can better access knowledge and technology for improving agricultural productivity is a key challenge, particularly given the growing complexity of agriculture and the decline of publicly funded extension systems. Extension programmes often make use of farmer to farmer extension and choose âmodel farmersâ, also called âmasterâ, âleadâ or âexpertâ farmers, to host demonstrations and train their fellow farmers on improved agricultural practices and innovations. Chosen on the basis of their expertise, model farmers are also assumed to be effective innovators and disseminators, but are they? This study sought to answer this question by examining a sample of 126 adopters of fast-growing leguminous fodder shrubs for feeding dairy cows and goats in Kenya. Criteria were established to rate farmers on their expertise as farmers, disseminators and innovators. Farmers were interviewed, indices were drawn up, and farmers were rated on the three categories. Forty-eight farmers were found to be expert farmers, 46 were expert innovators and 44 were expert disseminators. Forty-eight did not fit into any category. There were no significant differences between disseminators and non-disseminators with respect to age, gender and level of education. Nor were there differences between innovators and non-innovators. These finding are encouraging, as they suggest that there are no important barriers related to these variables preventing farmers from becoming innovators or disseminators. In contrast, expert farmers did tend to be wealthier and have larger land holdings than non-experts. There was some overlap among the expert farmers, innovators and disseminators, with 17 farmers being designated as members of all three categories. A log-linear regression model analysis revealed that farming and dissemination expertise are positively associated, as are innovation and di
ssemination expertise. However, farming expertise and innovation expertise are not associated. Moreover, 19 (40%) of 48 expert farmers were not effective disseminators. This finding suggests that extension programmes that choose farmer trainers on the basis of their farming expertise and their dissemination skills will promote dissemination more effectively than those that choose trainers only on the basis of their farming expertise
Replication data for: Development pathways in medium-high potential Kenya: a meso-level analysis of agricultural patterns and determinants.
No full textSample aerial photographs used were obtained from Department of resource surveys and remote sensing (DRSRS) for the year 1997. The photography was done between the months of May June July after the long rains and when the maize crop has taslled. The photos are obtained using an aircraft flying at 1500m above ground level and equipped with a 35-mm camera, a 200mm lens and a 200 Ektachrome film. The slides produced are projected onto
a 100 Dot grid paper on a wall and analysed for land use land cover and any other land parameters required. The number of times a certain use or cover type corresponds with the dot is recorded as the percentage cover for that type. The other parameters as mentioned in the introduction were directly counted on the projected slide and recorded as described later. A total of approx. 5700 slides were interpreted. The information was recorded and entered into computer using Access data entry forms and saved in Excel Format. The objective of the project was to interpret the 1997 land use / land cover Low level flying Aerial Sample Photos to derive the following information, a.)Percentage land use / land cover estimates for 5,747 aerial photo slides according to categories identified in Table 2 of the document b.)The number of mabati houses, thatched houses, houses with or presence of electrical poles, houses adjacent to or presence of streams or irrigation channels, number of schools, worship houses and factories. c.)The number of gullies d.)Percentage tree canopy cover e.)Percentage area under severe soil erosio