A comparative and systems approach to banana cropping systems in the Great Lakes region

To explore the diversity and efficiency of smallholder farms, we developed an approach based on a comparative framework and a systems analysis, Five sites in three countries (Rwanda, Burundi and Democratic Republic of Congo) were studied in parallel to take account of variations in agro-ecological and institutional conditions. In a systems-based perspective, we used a combination of quantitative (field measurements, economic valuation) and qualitative methods (semi-directed interviews) to capture the diverse nature of smallholder cropping systems. The novelty of the approach is that qualitative dimensions are included in the farm-level diagnostics, while maintaining a comprehensive and reproducible tool for systems analysis in terms of performance, constraints and drivers. The highest productivity in terms of annual revenue/ha was observed in the medium-sized farms (0.7-1.0 ha). It was also in this category that the number of crops cultivated was the greatest. Our hypothesis is that this high efficiency is the outcome of a system '\There productivity and risk management are optimized

Mapping QTL involved in adult plant resistance to powdery mildew in the winter wheat line RE714 in two susceptible genetic backgrounds

absen

Coffee/Banana intercropping as an opportunity for smallholder coffee farmers in Uganda, Rwanda and Burundi

Coffee is a primary cash crop and banana a primary food crop in the East African highlands region, including Rwanda, Burundi, north-west Tanzania, west and central Kenya and eastern Democratic Republic of Congo. These two crops often occur on the same smallholder farms, either planted on separate plots or intercropped. In certain countries, intercropping coffee and banana is voluntarily practised, while in others governments recommend growing these crops on separate plots. Even if intercropping coffee and banana leads to a decrease in coffee yields under certain conditions, it gives certain advantages to smallholder farmers. Intercropping offers higher returns per unit of land compared with coffee alone. Farmers increasingly resort to intercropping as a result of declining farm sizes, and in an effort to reduce risks related to income and food security. Researchers have identified the potential opportunity for intercropping coffee and banana for smallholder farmers, but many public and private development partners have not yet fully embraced this technology. The benefits and constraints of intercropping coffee and banana are discussed based on results from Burundi, Rwanda and Uganda. The aim is to understand the drivers of this system in Uganda, where intercropping is a common practice, so that a framework can be suggested to develop research and recommendations for intercropping coffee and bananas in Burundi and Rwanda, where intercropping is under experimentation and has high potential

Multi-messenger Observations of a Binary Neutron Star Merger

International audienceOn 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of $\sim 1.7\,{\rm{s}}$ with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg(2) at a luminosity distance of ${40}_{-8}^{+8}$ Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 $\,{M}_{\odot }$. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at $\sim 40\,{\rm{Mpc}}$) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∼10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position $\sim 9$ and $\sim 16$ days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta