Identification and Toxigenicity of Aspergillus spp. from Soils Planted to Peanuts in Eastern Zambia

It is not known which aflatoxigenic species are present in Zambia. Therefore, soil samples were collected during May to June 2012, at the end of the growing season in Eastern Province, from 399 farmers' fields that had been planted to groundnut (Arachis hypogaea L.) in Nyimba, Petauke, Mambwe, and Chipata Districts. Population densities of Aspergillus spp. were estimated by plating 10−3 soil dilutions on modified dichloran rose Bengal (MDRB) media. To test for toxigenicity, colonies were randomly selected from MDRB dilution plates, single-spored, transferred to vials with yeast extract sucrose (YES) liquid media, and grown for a week at room temperature. Agra Strip ® lateral flow cards were then used to test the filtered extracts, from the YES cultures, for total aflatoxin at 4 and 20 parts per billion (ppb). We identified Aspergillus flavus (small and large sclerotia strains), A. parasiticus, A. niger, A. nomius, A. oryzae, A. tamarii, and A. terreus. 100% of the S-strain A. flavus isolates produced aflatoxin at 4 and 20 ppb, whereas 86% and 56% of the L-strain A. flavus isolates produced aflatoxins at 4 and 20 ppb, respectively. All the A. nomius isolates produced aflatoxins at 4 and 20 ppb. 79% and 64% the A. parasiticus isolates produced aflatoxins at 4 and 20 ppb. To our knowledge, this is the first peer reviewed report from Zambia documenting the population densities of A. flavus across different agroecologies. In addition, it is also the first report on the identification of different Aspergillus spp., such as A. nomius, A. terreus, A. oryzae, and A. tamarii from Zambia. This information, taken together with cropping practices, soil characteristics, agroecological and climatic data, can form a basis for developing holistic pre-harvest aflatoxin mitigation strategies

Aflatoxin B1 contamination of groundnut Arachis hypogaea L. in eastern Zambia

Groundnut is a rich source of protein and it is the second most widely grown crop in eastern Zambia. A survey was conducted in 2012 to determine the incidence of aflatoxin B1 contamination in groundnuts from several districts important in groundnut production in eastern Zambia. Nyimba and Mambwe districts are in the Luangwa Valley and are comparatively hotter and drier than Chipata and Petauke districts which lie in the cooler plateau. 399, 1 kg unshelled groundnut samples were collected from farmers’ fields and also from homesteads upto 1 month after harvest. Aflatoxin B1 was assayed in each shelled sample by weighing and comminuting 100 g subsample and extracting aflatoxin from six 20 g aliquots. ELISA was used to estimate aflatoxin levels and the six values averaged to give the sample contamination. 34 and 27% of samples from Nyimba (maximum=4,980 ppb and arithmetic mean [AM] =1.1) and Mambwe (maximum=69 ppb and AM=0.7), respectively, had aflatoxin levels greater than 20 ppb. In comparison, 38 and 28% of samples from Petauke (maximum=3,258 ppb and AM=0.9) and Chipata (maximum=1,077, and AM= 0.8), respectively, had aflatoxin levels greater than 20 ppb. At the beginning of the season, priority is given to planting maize and cotton, while planting groundnut is delayed, increasing the risk of the crop being exposed to end-of-season drought. The aflatoxin contamination levels we report are a barrier to trade and the well being of consumers

A Case for Regular Aflatoxin Monitoring in Peanut Butter in Sub-Saharan Africa: Lessons from a 3-Year Survey in Zambia

A 3-year comprehensive analysis of aflatoxin contamination in peanut butter was conducted in Zambia, sub-Saharan Africa. The study analyzed 954 containers of 24 local and imported peanut butter brands collected from shops in Chipata, Mambwe, Petauke, Katete, and Nyimba districts and also in Lusaka from 2012 to 2014. For analysis, a sample included six containers of a single brand, from the same processing batch number and the same shop. Each container was quantitatively analyzed for aflatoxin B1 (AFB1) in six replicates by using competitive enzyme-linked immunosorbent assay; thus, aflatoxin contamination level of a given sample was derived from an average of 36 test values. Results showed that 73% of the brands tested in 2012 were contaminated with AFB1 levels >20 μg/kg and ranged up to 130 μg/kg. In 2013, 80% of the brands were contaminated with AFB1 levels >20 μg/kg and ranged up to 10,740 μg/kg. Compared with brand data from 2012 and 2013, fewer brands in 2014, i.e., 53%, had aflatoxin B1 levels >20 μg/kg and ranged up to 1,000 μg/kg. Of the eight brands tested repeatedly across the 3-year period, none consistently averaged ≤20 μg/kg. Our survey clearly demonstrates the regular occurrence of high levels of AF B1 in peanut butter in Zambia. Considering that some of the brands tested originated from neighboring countries such as Malawi, Zimbabwe, and South Africa, the current findings provide a sub-Saharan regional perspective regarding the safety of peanut butter

Pigeonpea improvement: An amalgam of breeding and genomic research

In the past five decades, constant research has been directed towards yield improvement in pigeonpea resulting in the deployment of several commercially acceptable cultivars in India. Though, the genesis of hybrid technology, the biggest breakthrough, enigma of stagnant productivity still remains unsolved. To sort this productivity disparity, genomic research along with conventional breeding was successfully initiated at ICRISAT. It endowed ample genomic resource providing insight in the pigeonpea genome combating production constraints in a precise and speedy manner. The availability of the draft genome sequence with a large‐scale marker resource, oriented the research towards trait mapping for flowering time, determinacy, fertility restoration, yield attributing traits and photo‐insensitivity. Defined core and mini‐core collection, still eased the pigeonpea breeding being accessible for existing genetic diversity and developing stress resistance. Modern genomic tools like next‐generation sequencing, genome‐wide selection helping in the appraisal of selection efficiency is leading towards next‐generation breeding, an awaited milestone in pigeonpea genetic enhancement. This paper emphasizes the ongoing genetic improvement in pigeonpea with an amalgam of conventional breeding as well as genomic research

Situational analyses on cowpea value chain in Zambia: the case of an untapped legume

Open Access JournalCowpea (Vigna unguiculata (L.) Walp) is a vital legume crop for Zambia’s urban and rural households. The crop is an important legume used as human and animal food and as a component of the agricultural production system, which improves the fertility of many depleted soils because of its ability to fix atmospheric nitrogen. Government through the ministries of health and agriculture recommend its’ use. Despite the importance of cowpea in the nation, there is limited information on the crop along with its’ value chain components. This review aims to assemble pertinent information on cowpea and its value chain components in Zambia. A critical look through the food system from production to consumption reveals the prevailing gaps in knowledge and output. The information covered here touches on crop breeding, production, marketing, processing, and consumption. This paper delves into various literature, bringing out the salient issues that are not commonly discussed about on the crop. It is a situation analyses focusing on finding solutions to improving the relevance and appreciation of the crop. There is a need for agricultural policies to promote cowpea production and use with the active participation of relevant actors. This would create a conducive environment for determining user needs, and leading to the development of beneficial impact-related activities at various stages. The country needs to begin incorporating a variety of crops within the food system to complement maize to improve nutrient intake, contribute to climate-smart practices, and sustainability of agricultural practices within communities in Zambia

Pigeonpea improvement: An amalgam of breeding and genomic research

In the past five decades, constant research has been directed towards yield improvement in pigeonpea resulting in the deployment of several commercially acceptable cultivars in India. Though, the genesis of hybrid technology, the biggest breakthrough, enigma of stagnant productivity still remains unsolved. To sort this productivity disparity, genomic research along with conventional breeding was successfully initiated at ICRISAT. It endowed ample genomic resource providing insight in the pigeonpea genome combating production constraints in a precise and speedy manner. The availability of the draft genome sequence with a large‐scale marker resource, oriented the research towards trait mapping for flowering time, determinacy, fertility restoration, yield attributing traits and photo‐insensitivity. Defined core and mini‐core collection, still eased the pigeonpea breeding being accessible for existing genetic diversity and developing stress resistance. Modern genomic tools like next‐generation sequencing, genome‐wide selection helping in the appraisal of selection efficiency is leading towards next‐generation breeding, an awaited milestone in pigeonpea genetic enhancement. This paper emphasizes the ongoing genetic improvement in pigeonpea with an amalgam of conventional breeding as well as genomic research