Chitedze Agricultural Research Station

Lilongwe, Malawi

Chitedze Agricultural Research Station

Lilongwe, Malawi
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Matumba L.,University of Malawi | Matumba L.,Chitedze Agricultural Research Station | Monjerezi M.,University of Malawi | Biswick T.,University of Malawi | And 2 more authors.
Food Control | Year: 2014

Samples of locally (Malawian) processed and imported maize- and groundnut-based food products (peanut butters, roasted groundnuts, peanut based therapeutic foods, instant baby cereals, maize puffs and de-hulled maize flour) were collected from popular markets of Lilongwe City, Malawi. The samples were analysed in order to determine the frequency and extent of aflatoxin contamination, using immuno-affinity column and reversed-phase liquid chromatography with post-column photochemical derivatization and fluorescence detection. No aflatoxins were detected in all samples of imported baby cereal and locally processed de-hulled maize flour. However, all locally processed maize based baby foods had aflatoxins above EU maximum tolerable level of 0.1μg/kg. In 75% of locally processed maize puffs, aflatoxins were detected at levels of up to 2μg/kg. Peanut based therapeutic foods had aflatoxin level between 1.6 and 2.9μg/kg, exceeding the EU tolerable maximum level (0.1μg/kg) set for food for health purposes. Locally processed peanut butters had aflatoxins levels in the range of 34.2-115.6μg/kg, which was significantly higher than their imported counterparts (<0.2-4.3μg/kg). Samples of locally processed skinned and de-skinned roasted groundnuts had aflatoxins in range of 0.5-2.5μg/kg and 0.6-36.9μg/kg, respectively. These results highlight the need for rigorous monitoring of aflatoxins in commercially available processed products in order to reduce likely health risks associated with dietary aflatoxin intake. © 2013 Elsevier Ltd.

Kamara A.Y.,International Institute Of Tropical Agriculture | Tefera H.,Chitedze Agricultural Research Station | Ewansiha S.U.,International Institute Of Tropical Agriculture | Ajeigbe H.A.,International Institute Of Tropical Agriculture | And 3 more authors.
Crop Science | Year: 2011

A field study was conducted to determine the rate of genetic improvement in grain and fodder yields and associated agronomic and physiological changes of determinate and semideterminate cowpea [Vigna unguiculata (L.) Walp.] genotypes developed in the Nigerian Sudan savannas in 1974 to 2004. Results showed that grain yield of determinate cowpea ranged from 796 kg ha -1 for cultivars released in the 1970s to 1485 kg ha -1 for cultivars released in the 2000s with a corresponding genetic gain of 2.93% per year. Mean grain yield of semideterminate cow-pea ranged from 638 to 1547 kg ha -1 with relative annual gain of 4.4%, suggesting that more progress was made in breeding semideterminate cowpea cultivars for high grain yield. Fodder yield of determinate cowpea ranged from 1493 kg ha -1 for culti-vars released in the 1970s to 2332 kg ha -1 for those released in 2000s, an average 1.74% genetic gain per year. For semideterminate cowpea, fodder yield increased from 1698 kg ha -1 for older cultivars to 2612 kg ha -1 for modern cultivars with relative annual gain of 2.15%. The general gain in fodder yield for both cowpea types indicated that selection for dual-purpose cowpea cultivars with increased fodder as well as grain yields has been successful. This study also revealed that genetic gains were made in the improvement of yield related traits such as pods per plant, 100-seed weight, total dry matter, and harvest index (HI) for both plant types. A remarkable progress has been made in increasing the total dry matter over the three decades period. This trait was significantly associated with grain yield (r = 0.60 for determinate cowpea and r = 0.53 for semidetermi-nate cowpea). Other traits that were significantly correlated with grain yield were fodder yield, number of pods per plant, and HI for determinate cowpea and fodder yield, HI, and 100-seed weight for semide-terminate cowpea. The strong relationship between grain and fodder yields showed the success made in selecting for dual-purpose cowpea cultivars. © Crop Science Society of America.

Tesfahunegn G.B.,Aksum University | Tesfahunegn G.B.,University of Bonn | Tamene L.,Chitedze Agricultural Research Station | Vlek P.L.G.,University of Bonn | Mekonnen K.,Aksum University
Land Degradation and Development | Year: 2016

Soil quality (SQ) assessment from farmers' point of view can be used as a primary indicator for planning sustainable agriculture. Despite this fact, limited information is documented with regard to SQ indicators, for example weed species, crop types and management practices from farmers' knowledge perspectives. The aims of this study are to analyse factors that determine farmers' knowledge of SQ, identify SQ indicators of weed species and crop types across different SQ status and assess soil-and-crop management practices that maintain SQ in the Mai-Negus catchment, northern Ethiopia. Fifty-two farmer household heads were chosen randomly for questionnaire interview. The results showed significant (p≤0·05) differences in the proportion of respondents who used different crop-and-soil management practices. The success of overall prediction by the logistic regression model (model χ2=0·84, p<0·01) and level of model correct predictions (86%) indicated that the explanatory variables have sufficiently explained farmers' knowledge of SQ indicators. Provided that other conditions remained constant, the odds ratio of variables such as farmer experience, access to information, farm location, education, field slope and land tenure have significantly increased the likelihood of farmers for being knowledgeable of SQ indicators. This study also demonstrated that most farmers are knowledgeable in identifying weed species, crop types and management practices across various SQ status, which suggests that such SQ indicators should be used to assess SQ status (degradation severity) while locating fields to be intervened using appropriate management strategies. © 2013 The Authors. Land Degradation & Development published by John Wiley & Sons, Ltd. © 2016 John Wiley & Sons, Ltd.

Matumba L.,University of Malawi | Matumba L.,Chitedze Agricultural Research Station | Van Poucke C.,Ghent University | Biswick T.,University of Malawi | And 3 more authors.
Food Control | Year: 2014

A total of 9 traditional maize based opaque beers were randomly collected from tribal (chewa) rituals and commercial village brewers from Lilongwe and Dowa districts, Malawi in August 2012 for evaluation of mycotoxins using a multi-mycotoxin method based on liquid chromatography-tandem mass spectrometry. Samples were analyzed for aflatoxins B1 (AFB1), AFB2, AFG1, AFG2, fumonisin B1 (FB1), FB2, FB3, zearalenone, ochratoxin A, nivalenol, deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, neosolaniol, fusarenon-X diacetoxyscirpenol, HT-2 toxin, T-2 toxin, alternariol, alternariol methyl ether, and sterigmatocystin. All beer samples were positive for fumonisins with FB1. +. FB2 and FB1. +. FB2. +. FB3 content of 1745. ±. 1294. μg/kg (mean. ±. std. dev.) and 1898. ±. 1405. μg/kg respectively. With exception of one beer sample, all the beers also contained aflatoxins at a mean concentration of 90. ±. 95. μg/kg. Consumption of 1.0-6.0. L of the traditional beer from this study translates to daily FB1. +. FB2 exposure of 29-174. μg/kg body weight (bw)/day (i.e. >provisional maximum tolerable daily intake of 2. μg/kg bw/day set by the Joint FAO/WHO Expert Committee on Food Additives) and aflatoxin exposure of 1.5-9.0. μg/kg bw/day for a 60. kg adult. The study demonstrated that the consumption of the maize based traditional home-made beer in Malawi can significantly enhance aflatoxins and fumonisin dietary exposure among beer consumers. © 2013 Elsevier Ltd.

Matumba L.,University of Malawi | Matumba L.,Chitedze Agricultural Research Station | Monjerezi M.,University of Malawi | Van Poucke C.,Ghent University | And 3 more authors.
World Mycotoxin Journal | Year: 2013

The bright greenish yellow fluorescence (BGYF) test has been used with varying success in screening for aflatoxins in maize. This test was applied to 180 maize samples collected from different markets within 12 districts of Malawi in order to evaluate its performance against high performance liquid chromatographic analysis. The number of BGYF grains in 2.5 kg unground samples ranged from 0 to 35 and about 49% of all tested samples had aflatoxin concentrations ranging from 1 to 382 μg/kg. A total of 65 (36%) of the examined unground samples showed no BGYF. The European Commission recommends a false negative rate of less than 5% for a screening technique to be acceptable. In this study, four BGYF grains per 2.5 kg unground maize sample successfully indicated an aflatoxin contamination of >10 μg/kg (10 μg/kg being the maxium tolerable level proposed by the Common Market for Eastern and Southern Africa), with a 4.4% false negative rate. In this case, the amount of confirmatory analyses would be reduced by 63%, if the BGYF test was employed as a screening method. The screening technique therefore offers a practical tool for Malawi and possibly for the Sub-Saharan region.

Matumba L.,Chitedze Agricultural Research Station | Monjerezi M.,University of Malawi | Khonga E.B.,Botswana College of Agriculture | Lakudzala D.D.,University of Malawi
Food Control | Year: 2011

Samples of sorghum grain and malt, traditional opaque sweet beverage (thobwa) and beer prepared from sorghum malts, were collected from the southern region of Malawi during the humid month of January. The samples were analyzed for total aflatoxins using aflatest VICAM fluorometry procedure. All malt and beer samples, 15% and 43% of the sorghum and thobwa samples, respectively, were contaminated with aflatoxins. The sorghum malt prepared for beer brewing, had a significantly (p < 0.01) higher total aflatoxin content (average 408 ± 68 μg/kg [SEM]) than any other type of sample. The average aflatoxin content in the beer was 22.32 μg/l, which is higher than the permissible maximum level in ready to eat foods set by Codex Alimentarius Commission (10 μg/kg). Thus consumption of opaque sorghum-based traditional beer poses a risk of aflatoxin exposure. © 2010 Elsevier Ltd.

Fandika I.R.,Kasinthula Agricultural Research Station | Kadyampakeni D.,Chitedze Agricultural Research Station | Zingore S.,Chitedze Agricultural Research Station
Irrigation Science | Year: 2012

The performance of a bucket drip irrigation system (BDI) powered by treadle pump was evaluated on tomato and intercropped maize/bean crops, between 2005 and 2007 in Malawi. It was a split plot experiment with three replicates. The BDI system consisted of a 1,300-l tank mounted 1. 5 m above ground and connected with a 32-mm mainline and 15-mm lateral lines spaced at 1 m by 0. 6 m. A treadle pump was used to uplift water to the tank. Tomato and intercropped maize/bean were irrigated every 4 days. The system reduced labour and water by > 5% and it showed high uniform application depth and wetted diameter. Yields were significantly different between tomato varieties (P < 0. 05). Maize/bean yields were highly significantly different between monoculture, intercropping system and bean varieties (P < 0. 001). Consequently, an economic analysis shows that there is a significant difference, in terms of net income, between the various crop enterprises. Tomato was more valuable with BDI, compared to maize and beans. It can be concluded that BDI, powered by a treadle pump, saves labour and time and it provides uniform irrigation for crop production. Therefore, tomato is recommended for use with this system, compared to maize and bean. © 2011 Springer-Verlag.

Ngwira A.,Chitedze Agricultural Research Station | Ngwira A.,Ghent University | Sleutel S.,Ghent University | de Neve S.,Ghent University
Nutrient Cycling in Agroecosystems | Year: 2012

Conservation agriculture (CA) characterised by minimal soil disturbance, permanent soil surface cover by dead or living plants and crop rotations is one way of achieving higher soil organic carbon (C) in agricultural fields. Sandy loam and loamy soil samples from zero tillage (ZT) and conventional tillage (CT) plots were taken from farmers' fields during the dry season in August 2006. Soil organic carbon (SOC) and soil organic nitrogen (SON), microbial biomass carbon (MB-C) and microbial biomass nitrogen (MB-N), C mineralization and SOC distribution in particle size fractions in 0-20 cm layer were evaluated. Forty eight farmers' fields were randomly sampled at four different locations in Central and Northern Malawi, representing ZT plots maintained for a different number of years, and ten fields under CT with similar soil type and crop grown were selected. SOC and SON in ZT fields were 44 and 41 % (4 years ZT) and 75 and 77 % (5 years ZT) higher, respectively, than CT plots. MB-C and MB-N in ZT fields were 16 and 44 % (4 years ZT) and 20 and 38 % (5 years ZT) higher, respectively, than CT plots. However, MB-C and MB-N in ZT fields were 27 and 25 % (2 years ZT) and 17 and 9 % (3 years ZT) lower than in CT plots. The proportion of the total organic C as microbial biomass C was relatively higher under CT than ZT treatments. The higher SOC and MB-C content in the ZT fields resulted in 10, 62, 57 % higher C mineralization rate in ZT plots of 3, 4 and 5 years of loamy sand soils and 35 % higher C mineralization rate in ZT plot of 2 years than CT of sandy loam soils in undisturbed soils in the laboratory. Simulating plough from the undisturbed soils that were used for C mineralization experiment resulted in linear curves indicating that all organic C was already depleted during the first incubation period. The relative distribution of soil organic matter (SOM) in silt and clay size fractions was strongly correlated (r = 0.907 and P ≤ 0.01) with silt percentages. Easily degradable carbon pool (C A,f) was correlated (r = 0.867 and P ≤ 0.05) with organic carbon in sand size fraction. In developing viable conservation agriculture practices to optimize SOC content and long-term sustainability of maize production systems, priority should be given to the maintenance of C inputs, crop rotations and associations and also to reduced soil disturbance by tillage. © 2012 Springer Science+Business Media B.V.

Kadyampakeni D.M.,Kasinthula Research Station | Kazombo-Phiri S.,Chitedze Agricultural Research Station | Mati B.,Jomo Kenyatta University of Agriculture and Technology | Fandika I.R.,Kasinthula Research Station
Irrigation and Drainage | Year: 2015

Agricultural water management interventions play a critical role in mitigating hunger during droughts and dry seasons in southern Africa. A study was conducted in Malawi to compare the performance of improved agricultural water management interventions with traditional water management practices to assess the performance of the interventions on crop yield and water use. The study used questionnaires and focused group discussions to collect data from farmers and key informants. The results showed significant gains using regulated surface irrigation compared with unregulated surface irrigation. The results showed that yield increases of 33 and 37% for onion and tomato respectively were obtained from wetland seepage irrigation compared with upland cultivation. Treadle pump irrigation increased crop production by 5-54% compared with water can irrigation. Treadle pumps also increased gross and net incomes by ≥12%, suggesting that farmers using the treadle pump were able to realize higher incomes across all crop enterprises compared with farmers using water cans. However, there is a dire need to improve the efficiency of the surface irrigation systems for rice production because the water applied was about two to three times the gross irrigation requirement which could result in environmental degradation through increased salinity and waterlogging. © 2014 John Wiley & Sons, Ltd.

Sileshi G.W.,Chitedze Agricultural Research Station | Arshad M.A.,University of Alberta | Konate S.,University of Abobo Adjame | Nkunika P.O.Y.,University of Zambia
Journal of Vegetation Science | Year: 2010

Objectives: To (1) assess the strength of evidence for the role of termites in vegetation heterogeneity in African savannas, and (2) identify the mechanisms by which termites induce such heterogeneity. Location: African savannas. Methods: We conducted a review of the literature, a meta-analysis and qualitative systems analysis to identify mechanisms to explain the observed patterns. Results: The review provided evidence for termite-induced heterogeneity in floristic composition and vegetation patterning in savannas across Africa. Termites induced vegetation heterogeneity directly or indirectly through their nest-building and foraging activities, associated nutrient cycling and their interaction with mammalian herbivores and fire. The literature reviewed indicated that termite mounds essentially act as islands of fertility, which are responsible for ecosystem-level spatial heterogeneity in savannas. This was supported by the meta-analysis, which demonstrated that mounds of Ancistrotermes, Macrotermes, Odontotermes (family Macrotermitinae), Cubitermes (family Termitinae) and Trinervitermes (Nasutitermitinae) are significantly enriched in clay (75%), carbon (16%), total nitrogen (42%), calcium (232%), potassium (306%) and magnesium (154%) compared to the surrounding savanna soil. Conclusions: Termite activity is one of the major factors that induce vegetation patterning in African savannas. The implications of this are discussed and research questions for future studies and modelling efforts are indicated. © 2010 International Association for Vegetation Science.

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