| 1. |
- Ekbom, Barbara
(författare)
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Organic soil fertility amendments and tritrophic relationships on cabbage in Uganda: Experiences from on-station and on-farm trials
- 2010
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Ingår i: African Journal of Agricultural Research. - 1991-637X. ; 5, s. 2862-2867
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Tidskriftsartikel (refereegranskat)abstract
- Organic soil fertility amendments may have direct or indirect pest management properties through an impact on crop characters and/or the pest's natural enemies. This study was carried out to assess the effect of utilizing market crop wastes (MCW) as soil fertility amendments on tritrophic relationships of cabbage. The study was conducted on-station for three consecutive seasons; and was verified on-farm for one season. Treatments included 1) MCW compost incorporated in soil; 2) Un-composted MCW incorporated in soil; 3) Un-composted MCW on the soil surface; 4) a chemical fertilizer (NPK) incorporated in the soil; and 5) the un-amended control. The treatments were arranged in a randomized complete block design with three replications. The MCW were applied at a rate of 12 tonnes/ha. Data was collected on plant attributes, pest population dynamics of two pest guilds, natural enemies, and cabbage yield. Results indicated that MCW compost amended plants consistently had the highest aphids and diamondback moth infestations; the highest natural enemies' counts and the highest cabbage yield. Correlations revealed that the soil fertility amendments had effects that cascaded to different trophic levels.
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| 2. |
- Hailu, Faris, et al.
(författare)
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Genetic variability of Ethiopian bread wheat genotypes (Triticum aestivum L.) using agro-morphological traits and their gliadin content
- 2016
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Ingår i: African Journal of Agricultural Research. - 1991-637X. ; 11, s. 330-339
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Tidskriftsartikel (refereegranskat)abstract
- Wheat is grown worldwide because it is a major diet component. The aim of this study was to investigate the genetic variation in bread wheat (Triticum aestivumL.) when grown in the Wollo highland areas, applying agro-morphological data and gliadin content. A total of twenty accessions of bread wheat received from Ethiopian Biodiversity Institute (EBI), Sirinka Agricultural Research Centre (SARC) and also newly collected accessions were planted in a randomized complete block design, starting mid-January, 2014, using irrigation. Agro-morphological data was recorded following the International Plant Genetic Resources Institute (IPGR) descriptors list, and the gliadin content was examined by acid page electrophoresis. Analysis of variance showed that most agro-morphological data varied significantly between accessions. By using both dendrogram based on agro-morphological traits and cluster analyses of gliadin, the accession 226944 and the landrace Debalit were found to cluster closely. Newly collected accessions and EBI accessions showed higher diversity than released varieties applying Nei’s genetic distance and gene diversity (H*) analysis. Accessions originating from the West part of the South Wollo province were found to be grouped together, applying principal component analysis. It can be concluded that high genetic variability exists on the bread wheat genotypes, some of them holding exceptionally promising values, making them interesting for further selection.
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| 3. |
- Kätterer, Thomas, et al.
(författare)
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Soil carbon dynamics, climate, crops and soil type –calculations using introductory carbon balance model (ICBM) and agricultural field trial data from sub-Saharan Africa
- 2012
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Ingår i: African Journal of Agricultural Research. - 1991-637X. ; 7, s. 5800-5809
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Tidskriftsartikel (refereegranskat)abstract
- A simple soil carbon model, the Introductory Carbon Balance Model (ICBM), is useful for projecting soil C dynamics in temperate and tropical land-use systems. A spreadsheet-based version of ICBM is presented, with an emphasis on African and short-and long term projections under variable conditions (climate, crops, soil). ICBM has two compartments, young and old soil C, and five parameters, intended to project soil C dynamics in a 30-year perspective even when detailed data are lacking. Information necessary is a rough estimate of annual carbon input to soil, a coarse measure of residue quality and some information about climate. If basic weather station data and water-related soil properties are available, more exact projections can be made. Typically, the model is used for answering questions such as: (1) If crop residues are returned to the field, how much will soil carbon increase after 30 years? (2) With limited local data available, will rough estimates (climate zone and crop yield etc) still make projections possible? Compared with more complex models, this approach is rapid and simple and yet still gives accurate results. The model is available as an Excel® spreadsheet, and which projections can be made and effects of different agricultural treatments can be compared. Here, agricultural field experiments in Africa are used to show how ICBM rapidly can be parameterized for conditions different from those it was originally calibrated for, and how projections can be made from this base parameterization. Concepts behind modeling approaches, as well as possible improvements, are also discussed.
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| 4. |
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| 5. |
- Mandere, Nicodemus, et al.
(författare)
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Assessing the contribution of alternative agriculture to poverty reduction and employment creation: A case study of sugar beet cultivation in Kenya
- 2011
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Ingår i: African Journal of Agricultural Research. - 1991-637X. ; 6:2, s. 440-450
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Tidskriftsartikel (refereegranskat)abstract
- In Kenya, the government is promoting high-value and drought resistant crop varieties in an effort to reduce poverty in rural areas. Sugar beet is one such crop. This study was conducted with two objectives: 1) to assess the opportunities and challenges for sugar beet cultivation and adoption in the Nyandarua district of Kenya and 2) to assess whether sugar beet adoption can offer an opportunity for escaping poverty for smallholder farmers in the district. The factors favoring sugar beet cultivation and adoption in the district include: adequate land area suitable for sugar beet cultivation and the high sugar beet yield that can be attained per unit suitable land area, farmers' awareness of the positive aspects of sugar beet cultivation, and the willingness of many farmers to grow the sugar beet crop. Notwithstanding these favorable conditions, some socio-economic factors-mainly the affordability of sugar beet production and possible lack of appropriate farming technologies, will present challenges to widespread sugar beet adoption, particularly to those farmers in the low-and medium-income categories. The sugar beet profit analysis showed that depending on the market price, sugar beet can potentially increase household net income. However, since the majority of households are in the low-and medium-income categories, for sugar beet to pull the smallholder farmers out of poverty, interventions from government and other stakeholders is of vital necessity. The impact of sugar beet adoption and cultivation will vary from household to household. Those households within the high-income category who can raise the required start up capital are likely to benefit, while the low-and medium-income households may not, which is true for any new crop with high start up costs. Alternative agriculture alone is therefore not a sufficient strategy to address the problems of poverty and unemployment. Any successful strategy to address these issues must be broad-based, and include alternative agriculture and other growth and development strategies. Provision for the entire necessary infrastructure should precede or accompany all of these strategies in order to optimize implementation benefits.
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| 6. |
- Millogo, Vinsoun, et al.
(författare)
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Day-to-day variation in yield, composition and somatic cell count of saleable milk in hand-milked zebu dairy cattle
- 2009
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Ingår i: African Journal of Agricultural Research. - 1991-637X. ; 4, s. 151-155
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to determine the relative day-to-day variation in yield and composition of zebu cows. Ten multiparous zebu cows in day 41 +/- 1.6 of lactation were used in the study. After a 14 day adaptation period, milk production was recorded daily for four consecutive weeks. Cows had access to natural pasture for 6.5 h per day and were also supplemented with hay, cottonseed cake and molasses. The cows were hand-milked and calves were used to stimulate milk ejection before and during milking. Average yield of saleable milk was 2.08 +/- 0.23 l/day with a relative day-to-day variation of 18-21%. The variation of saleable milk was 23-25% for fat, 12-14% for protein, 6% for lactose and 8% for somatic cell count. The variation in fat content was higher in strip milk (19-46%) than in saleable milk. The results indicated a larger variation in composition of milk from hand-milked Bos indicus Zebu than from machine-milked Bos taurus cows. The most likely reasons for the difference in variation are the suckling by the calf and that hand-milking entails larger variation in the degree of emptying machine-milking does.
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| 7. |
- Mohammed, B., et al.
(författare)
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Nutritive values of the drought tolerant food and fodder crop enset
- 2013
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Ingår i: African Journal of Agricultural Research. - : Academic Journals. - 1991-637X. ; 8:20, s. 2326-2333
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Tidskriftsartikel (refereegranskat)abstract
- Enset (Ensete ventricosum) is a drought tolerant crop, traditionally grown in Ethiopia. It has manyusages: food, fodder, fibres and traditional medicine. Being perennial, enset improves local climate andsoil conditions. It could contribute to improved food security in several drought-prone parts of theworld. The aims of this study were to reveal the amino acids of enset corm, which can be cooked as aroot crop, and to increase the general knowledge regarding chemical composition and energy values ofdifferent enset fractions. Water content was high, 85 to 90%, which is beneficial when used as fodderduring dry periods. Enset corm contained 17 of 20 amino acids and had similar or higher concentrationthan potato of 12 of these. Leaves had 13% protein, among the highest available in Ethiopia, 20% crudefibre and 10% sugar; a good fodder and suitable for ensilage. The pseudostem, the main food source,was rich in soluble carbohydrates (80%) and starch (65%), but had low protein content (4%). An ensetbased diet should be supplemented with protein and complementary amino acids; for example frombeans, which are suitable to intercrop with enset.
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| 8. |
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| 9. |
- Mukangango, Marguerite, et al.
(författare)
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Effect of cutting height on nutritional characteristics of three agroforestry tree legume species and their feed supplement value on Chloris gayana Kunth
- 2018
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Ingår i: African Journal of Agricultural Research. - 1991-637X. ; 13, s. 1591-1597
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the effect of cutting height (30 and 100 cm) on chemical composition and in vitro digestibility in field-grown Acacia angustissima (Mill.) Kuntze. (Prairie acacia), Leucaena pallida Britton & Rose (guaja) and Mimosa scabrella Bentham. (bracatinga) legumes and their value in supplementing a basal diet of Chloris gayana Kunth. (Rhodes grass). Cutting height did not affect major chemical composition. Crude protein (CP) was highest in A. angustissima and lowest in M. scabrella, while neutral detergent fibre (NDF) and acid detergent fibre (ADF) were highest in M. scabrella. Degradation parameters were greater at 100 cm cutting height. L. pallida showed high in vitro organic matter digestibility but A. angustissima had the highest metabolisable energy. Addition of A. angustissima, L. pallida and M. scabrella to the basal diet increased improved the nutritional value and increased the CP content from 8.4 to 19.8% and 18.1 and 16.1%, respectively. Cutting height of A. angustissima, L. pallida and M. scabrella had no effect on their nutritional value. Their other functions and benefits will determine choice of cutting height as management practice when used on farms.
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| 10. |
- Njuguna, Jane Wangu, et al.
(författare)
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A canker and dieback disease threatening the cultivation of Grevillea robusta on small-scale farms in Kenya
- 2011
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Ingår i: African Journal of Agricultural Research. - 1991-637X. ; 6, s. 748-756
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Tidskriftsartikel (refereegranskat)abstract
- A canker and dieback disease was recently reported on Grevillea robusta in east Africa but little was known about its magnitude, distribution and associated pathogens. In our survey of the disease approximately 36% of 17,994 G. robusta trees assessed showed canker and dieback symptoms. Disease index increased from the humid zone (18%) and to the semi-arid zones (67%). Tree mortality increased from 0.3 to 20% respectively on the same scale and was highest in trees less than 7 years old in all zones. Disease index and tree mortality showed positive correlations with drought period which increased from an average of 0.7 months (humid) to 7 months (semi-arid zones). Both variables showed negative correlations with farm altitude. Disease index was higher in the woodlots compared to other types of tree planting in all zones. Two Botryosphaeriaceae species, Neofusicoccum parvum and Lasiodiplodia theobromae known to be pathogenic on G. robusta were highly abundant in severely diseased stems and branches and their occurrence also showed positive correlations with disease severity. From the results of this study, it was recommended that G. robusta should not be planted in the semi arid zones of Kenya, due to its susceptibility to the canker and dieback disease.
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