Participatory evaluation of groundnut planting methods for pre-harvest aflatoxin management in Eastern Province of Zambia

Aflatoxin contamination remains a major challenge for smallholder groundnut producers in Southern Africa. This is compounded by the stringent aflatoxin regulatory regimes in the lucrative international markets that continue to deny groundnuts produced in this region the access to markets. Participatory on-farm experiments were carried in 2016 and 2017 in Chinkhombe (Katete) and Kalichero (Chipata), and on-station trials at Mount Makulu Central Research Station (Chilanga) to evaluate the efficacy of groundnut planting methods: planting in double rows, single rows, tied ridges and on flatbeds, for pre-harvest aflatoxin management. Planting on flatbeds (no ridges), a popular planting method in most parts of Zambia was designated as the baseline. Significantly low (p < 0.05) levels of aflatoxin, (10.3 ± 3.1 mg/kg) were recorded in the groundnuts planted on tied ridges, and less than 22% of these had aflatoxin levels above the Zambia regulatory limit of 10 mg/kg, compared to more than 40% in other methods. Except for double rows, significantly higher pod yield, 1193 kg/ha, was recorded in groundnuts planted on tied ridges compared to other pre-harvest management options. A reduction of 37 and 81% in aflatoxin contamination was observed in groundnuts planted on single rows and tied ridges, respectively compared to an increase of 39.2% in double rows above 54.3 ± 10.9 mg/kg recorded in flatbeds. In addition, tied ridging was observed to improve plant vigour, lower disease incidence, insect pest and weed infestation. It is clear that the evaluation of these practices on-farm enabled more farmers to be more aware of the effects of these methods and get motivated to adopt them. It is thus imperative that participatory on-farm evaluations of existing aflatoxin management options are carried out as they are an essential step in influencing adoption and uptake of preharvest management control methods among smallholder farmers

Managing aflatoxin in smallholder groundnut production in Southern Africa: Paired comparison of the windrow and Mandela cock techniques

Timely drying of groundnuts is important after harvest. In most parts of sub-Saharan Africa, moisture content reduction is practically achieved by solar drying. In particular, the groundnuts are traditionally cured in the field using the inverted windrow drying technique. Recently, the Mandela cock technique, a ventilated stack of groundnut plants with a chimney at the center, has been introduced in the southern Africa region with the aim of reducing moisture content and the risk of aflatoxin contamination. An on-farm study was conducted in Malawi to compare the effectiveness of the Mandela cock and Windrow drying techniques with respect to aflatoxin control. For two consecutive years, farmers (2016, n = 29; 2017; n = 26) were recruited to test each of the two drying techniques. A mixed-design ANOVA showed that the Mandela cock groundnut drying technique led to sig- nificantly (p < 0.001) higher aflatoxin levels in groundnut seed compared to the traditional inverted windrow drying (5.7 μg/kg, geometric mean vs 2.5 μg/kg in 2016 and 37.6 μg/kg vs 8.4 μg/kg in 2017). The present findings clearly demonstrate the need for regulation and technology validation if farmers and consumers are to benefit

Sourcing high tissue quality brains from deceased wild primates with known socio‐ecology

The selection pressures that drove dramatic encephalisation processes through the mammal lineage remain elusive, as does knowledge of brain structure reorganisation through this process. In particular, considerable structural brain changes are present across the primate lineage, culminating in the complex human brain that allows for unique behaviours such as language and sophisticated tool use. To understand this evolution, a diverse sample set of humans' closest relatives with varying socio-ecologies is needed. However, current brain banks predominantly curate brains from primates that died in zoological gardens. We try to address this gap by establishing a field pipeline mitigating the challenges associated with brain extractions of wild primates in their natural habitat. The success of our approach is demonstrated by our ability to acquire a novel brain sample of deceased primates with highly variable socio-ecological exposure and a particular focus on wild chimpanzees. Methods in acquiring brain tissue from wild settings are comprehensively explained, highlighting the feasibility of conducting brain extraction procedures under strict biosafety measures by trained veterinarians in field sites. Brains are assessed at a fine-structural level via high-resolution MRI and state-of-the-art histology. Analyses confirm that excellent tissue quality of primate brains sourced in the field can be achieved with a comparable tissue quality of brains acquired from zoo-living primates. Our field methods are noninvasive, here defined as not harming living animals, and may be applied to other mammal systems than primates. In sum, the field protocol and methodological pipeline validated here pose a major advance for assessing the influence of socio-ecology on medium to large mammal brains, at both macro- and microstructural levels as well as aiding with the functional annotation of brain regions and neuronal pathways via specific behaviour assessments