The distribution and incidence of banana Fusarium wilt in subsistence farming systems in east and central Africa

2016 ◽  
Vol 84 ◽  
pp. 132-140 ◽  
Author(s):  
Patrick Karangwa ◽  
Guy Blomme ◽  
Fenton Beed ◽  
Celestin Niyongere ◽  
Altus Viljoen
Keyword(s):  
Fusarium Wilt ◽  
Central Africa ◽  
Farming Systems ◽  
Subsistence Farming

The Use of Manure on Smallholders' Farms in Semi-Arid Eastern Kenya

1995 ◽  
Vol 31 (3) ◽  
pp. 371-381 ◽  
Author(s):  
M. E. Probert ◽  
J. R. Okalebo ◽  
R. K. Jones
Keyword(s):  
Current Practice ◽  
Ammonia Volatilization ◽  
Farming Systems ◽  
Poor Quality ◽  
Soil Samples ◽  
Scarce Resource ◽  
Subsistence Farming ◽  
Important Resource ◽  
Semi Arid

SummaryThe manure that is returned to croplands each year is an important resource in the subsistence farming systems of eastern Kenya. Measurements on several farms have shown that the manure being used is of very poor quality. Analyses of soil samples from beneath the bomas (small enclosures) where animals are kept indicate that substantial losses of nutrients occur through leaching; ammonia volatilization and denitrification may also be involved. Current practice is to apply the manure at rates that appear to make poor use of this scarce resource. The findings are discussed in terms of what changes to the system may be feasible to reduce losses of nutrients, and to improve the quality of the manure and the effectiveness of its use.

scholarly journals The development of a multiplex PCR assay for the detection of Fusarium oxysporum f. sp. cubense lineage VI strains in East and Central Africa

2020 ◽  
Vol 158 (2) ◽  
pp. 495-509 ◽  
Author(s):  
P. Ndayihanzamaso ◽  
P. Karangwa ◽  
D. Mostert ◽  
G. Mahuku ◽  
G. Blomme ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Multiplex Pcr ◽  
Fusarium Wilt ◽  
Central Africa ◽  
East African ◽  
Pcr Assay ◽  
Vegetative Compatibility Groups ◽  
Worldwide Population ◽  
Multiplex Pcr Assay ◽  
Disease Free

Abstract Banana is a staple food and cash crop grown in East and Central Africa (ECA). The main banana varieties grown in ECA are the East African highland bananas (EAHB), although dessert/beer bananas such as Sukari Ndizi, Kayinja (Pisang Awak) and Gros Michel are also produced due to their high value at local markets. The Fusarium wilt fungus Fusarium oxysporum f. sp. cubense (Foc) causes disease of susceptible dessert/beer bananas, which significantly reduces yields. Banana Fusarium wilt is managed by excluding the pathogen from disease-free areas and by planting disease-resistant varieties in infested fields. Six phylogenetically closely-related vegetative compatibility groups (VCGs) of Foc, VCGs 0124, 0125, 0128, 01212, 01220 and 01222 are present in ECA, which all group together in Foc Lineage VI. Rapid and accurate detection of Foc Lineage VI strains is thus important to prevent its spread to disease-free areas. In this study, molecular markers specific to Foc Lineage VI were therefore developed. Primer sets were then combined in a multiplex PCR assay, and validated on a worldwide population of 623 known Foc isolates, other formae speciales and non-pathogenic Fusarium oxysporum isolates. The Foc Lineage VI multiplex PCR was used to identify Foc isolates collected in banana fields at five locations in Uganda and Tanzania. Foc Lineage VI DNA was detected at a concentration as low as 0.1 ng/μl, both in the absence and presence of banana DNA, and can therefore be used as an accurate diagnostic tool for Foc Lineage VI strains.

Transaction Costs and the Marketable Surplus of Milk in Smallholder Farming Systems of the Gambia

2005 ◽  
Vol 34 (3) ◽  
pp. 189-195 ◽  
Author(s):  
Jacques Somda ◽  
Eric Tollens ◽  
Mulumba Kamuanga
Keyword(s):  
Smallholder Farmers ◽  
Farming Systems ◽  
The Gambia ◽  
Perfect Competition ◽  
Subsistence Farming ◽  
Smallholder Farming ◽  
Economic Paradigm ◽  
Marketable Surplus ◽  
Milk Marketing ◽  
Cost Factors

The neoclassical economic paradigm views market linkages as efficient mechanisms for trading. However, the validity of this position is questionable, as markets frequently do not possess the structural conditions necessary for perfect competition. In subsistence-farming systems, factors that prevent greater participation of smallholders in markets can be found from the production level to the access to markets themselves. This study investigates the transaction-cost factors operating in smallholder dairy farms in The Gambia. The results indicate that access to market at the farm gate, the number of local cows and the distance to the nearest city increase the likelihood of market participation by producers and the marketing of surpluses of dairy products. Increases in home consumption lead to decreases in sales and of farmers' participation in milk marketing. To achieve pro-poor rural growth, it is therefore essential to address explicitly the low productivity of dairy cattle, low capital endowments and market accessibility for smallholder farmers.

scholarly journals Understanding the Dynamic of Rice Farming Systems in Southern Mozambique to Improve Production and Benefits to Smallholders

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1018
Author(s):  
Fátima Ismael ◽  
Aires A. Mbanze ◽  
Alexis Ndayiragije ◽  
David Fangueiro
Keyword(s):  
Smallholder Farmers ◽  
Farming Systems ◽  
Multinomial Logit Model ◽  
Farming System ◽  
Rice Production ◽  
Rice Farming ◽  
Subsistence Farming ◽  
Rice Farmers ◽  
Crop Types ◽  
Mixed Crops

Rice farming systems (RFSs) in southern Mozambique are very heterogeneous and diversified, which has implications for smallholders’ adoption of each RFS, as well as on rice production and productivity in the region. In this regard, it is important to understand: (i) which RFS typologies can be leveraged to improve rice production and productivity; (ii) the drivers for smallholder farmers’ decisions to adopt an RFS; and (iii) which policies/incentives could enhance existing RFSs. The present study was based on surveys of 341 smallholder rice farmers in the Chókwè Irrigation Scheme (CIS), southern Mozambique. Data on the productivity of rice, size of the herd, and total other crop types were used to frame the RFS typologies. A multinomial logit model (MLM) and multiple linear regression (MLR) were applied to determine the driver for each RFS, and predict the constraints for production and yield. Based on cluster analysis, four typologies of RFSs were identified: the subsistence farming system (FS), specialised rice FS, mixed crops FS, and rice–livestock FS. Farms with longer experience reported applying more fertiliser and seedlings per unit hectare. The availability of labour increased the likelihood of adopting the mixed crops FS and rice–livestock FS. Older households were more likely to adopt the subsistence FS, and live closer to the farming fields. Yield of rice was positively associated with inputs such as fertilisers, pesticides, and seedlings, as well as years of experience of the household. Our results suggest that smallholder farmers need more assistance and technical support to identify and adopt more productive and less costly RFSs in this region.

Occurrence of Toxigenic Fungi and Aflatoxin Potential of Aspergillus spp. Strains Associated with Subsistence Farmed Crops in Haiti

2017 ◽  
Vol 80 (4) ◽  
pp. 626-631 ◽  
Author(s):  
Junior Aristil ◽  
Giovanni Venturini ◽  
Alberto Spada
Keyword(s):  
Low Income ◽  
Farming Systems ◽  
Weather Conditions ◽  
Subsistence Farming ◽  
Fusarium Spp ◽  
Toxigenic Fungi ◽  
Low Income Country ◽  
Growing Season Length ◽  
Species Specific

ABSTRACT Subsistence farming and poor storage facilities favor toxigenic fungal contamination and mycotoxin accumulation in staple foods from tropical countries such as Haiti. The present preliminary study was designed to evaluate the occurrence of toxigenic fungi in Haitian foodstuffs to define the mycotoxin risk associated with Haitian crops. The objectives of this research were to determine the distribution of toxigenic fungi in the Haitian crops maize, moringa, and peanut seeds and to screen Aspergillus section Flavi (ASF) isolates for production of aflatoxins B1 and G1 in vitro. Maize, moringa, and peanut samples were contaminated by potential toxigenic fungal taxa, mainly ASF and Fusarium spp. The isolation frequency of Aspergillus spp. and Fusarium spp. was influenced by locality and thus by farming systems, storage systems, and weather conditions. Particularly for ASF in peanut and maize samples, isolation frequencies were directly related to the growing season length. The present study represents the first report of contamination by toxigenic fungi and aflatoxin in moringa seeds, posing concerns about the safety of these seeds, which people in Haiti commonly consume. Most (80%) of the Haitian ASF strains were capable of producing aflatoxins, indicating that Haitian conditions clearly favor the colonization of toxigenic ASF strains over atoxigenic strains. ASF strains producing both aflatoxins B1 and G1 were found. Understanding the distribution of toxigenic ASF in Haitian crops and foodstuffs is important for determining accurate toxicological risks because the toxic profile of ASF is species specific. The occurrence of toxigenic fungi and the profiles of the ASF found in various crops highlight the need to prevent formation of aflatoxins in Haitian crops. This study provides relevant preliminary baseline data for guiding the development of legislation regulating the quality and safety of crops in this low-income country.

Consistency of performance of early-maturing maize cultivars in Striga-infested and Striga-free environments

2015 ◽  
Vol 95 (6) ◽  
pp. 1073-1084
Author(s):  
Baffour Badu-Apraku ◽  
Chabi Yallou ◽  
Muhyideen Oyekunle ◽  
Richard Akinwale ◽  
G. Aweke ◽  
...  
Keyword(s):  
Grain Yield ◽  
Central Africa ◽  
Farming Systems ◽  
Striga Hermonthica ◽  
Management Options ◽  
Maize Cultivars ◽  
Striga Resistance ◽  
Early Maturing ◽  
Republic Of Benin ◽  
High Consistency

Badu-Apraku, B., Yallou, C., Oyekunle, M., Akinwale, R., Aweke, G. and Kamara, A. 2015. Consistency of performance of early-maturing maize cultivars in Striga-infested and Striga-free environments. Can. J. Plant Sci. 95: 1073–1084. Despite the immense potential of maize (Zea mays L.) in savannas of West and Central Africa (WCA), production and productivity is constrained by Striga hermonthica parasitism. Sixteen early-maturing cultivars were evaluated at two locations in Nigeria and three locations in the Republic of Benin from 2007 to 2009 to assess the grain yield, stability and the consistency of the rankings of the cultivars under Striga-infested and Striga-free environments. The combined analysis of variance showed significant (P<0.01) cultivar and cultivar×environment interactions for grain yield and other traits under Striga-infested and Striga-free environments. The test of concordance was significant (P<0.001) for grain yield (W=0.68), number of emerged Striga plants (W=0.74) and Striga damage (W=0.56) under Striga infestation, indicating stability of resistance in the cultivars developed from diverse sources under artificial S. hermonthica infestation across environments. There was high consistency of the rankings of the cultivars for grain yield and other Striga-resistance traits under Striga-infested and Striga-free environments in Benin and Nigeria. The additive main effects and multiplicative interaction (AMMI) biplot analysis for grain yield revealed POOL15SR/ACR94TZECOMP5-W/ACR94TZECOMP5-W and 2004 TZE-Y Pop DT STR C4 as the most stable cultivars with above-average mean grain yield in Striga-infested environments and they can be combined with other crop management options to control the parasite in the Striga endemic environments. Cultivars TZE Comp 5-W C7F2 and TZE Comp5-Y C6 S6 (Set B) had less Striga damage and number of emerged Striga plants across test environments. These cultivars could therefore serve as unique sources of favorable alleles for improving Striga resistance in maize in different production environments and farming systems.

scholarly journals Genetic Diversity of Fusarium oxysporum f. sp. cubense in East and Central Africa

Plant Disease ◽  
2018 ◽  
Vol 102 (3) ◽  
pp. 552-560 ◽  
Author(s):  
Patrick Karangwa ◽  
Diane Mostert ◽  
Privat Ndayihanzamaso ◽  
Thomas Dubois ◽  
Björn Niere ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Disease Management ◽  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Management Practices ◽  
Management Strategies ◽  
Central Africa ◽  
Elongation Factor ◽  
Intergenic Spacer ◽  
Intergenic Spacer Region

Banana Fusarium wilt is a major production constraint globally and a significant threat to the livelihoods of millions of people in East and Central Africa (ECA). A proper understanding of the diversity and population dynamics of the causal agent, Fusarium oxysporum f. sp. cubense (Foc), could be useful for the development of sustainable disease management strategies for the pathogen. The current study investigated the diversity of Foc in ECA using vegetative compatibility group (VCG) analysis, PCR-RFLPs of the ribosomal DNA’s intergenic spacer region, as well as phylogenetic analysis of the elongation factor-1α gene. Six VCGs (0124, 0125, 0128, 01212, 01220, and 01222), which all belong to one lineage (Foc lineage VI), were widely distributed throughout the region. VCGs 0128 and 01220 are reported for the first time in Burundi, the Democratic Republic of Congo (DRC), Rwanda, Tanzania, and Uganda, while VCG 01212 is reported in the DRC and Rwanda. Isolates that did not belong to any of the known VCGs were identified as Foc lineage VI members by phylogenetic analysis and may represent novel VCGs. CAV 2734, a banana pathogen collected in Rwanda, clustered with nonpathogenic F. oxysporum isolates in lineage VIII. Results from this study will contribute significantly toward the implementation of banana Fusarium wilt disease management practices in the region, such as the restricted movement of infected planting material and the selective planting of resistant banana varieties.

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