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Sustaining crop production and productivity in sub-Saharan Africa requires the availability and use of quality seed of improved varieties by smallholder farmers. The private sector has been considered as the best way to sustain seed supply and crop productivity. Unfortunately, the private sector’s share in the seed production and delivery in sub-Saharan Africa countries has not been very substantial for decades. As a consequence, farmer access to quality seed of recently released varieties remains very low. This manuscript analyzes the experiences of informal seed producers who graduated to formal private seed enterprises to understand the effectiveness of the support they receive to become viable seed ventures. We used comparative research methods to analyze the qualitative and quantitative data collected to understand the underlying mechanisms. The findings showed that the analyzed seed enterprises started with as little as about USD 300 and have already multiplied over tenfold their initial capital. They benefited from a wide variety of supports, e.g., quality seed production, marketing, partnerships, and value chain development trainings and infrastructures, from extension workers, research centers, national and international NGOs, and the other private seed enterprise operators like large public seed enterprises and agro-dealers. The seed enterprises are producing pre-basic, basic, and certified seed of cereals and self-pollinated legume crops delivered directly to farmers, institutional markets, and agro-dealers. The seed production data have been increasing for the past three years with an area expanding from about 30 ha to over 150 ha per year for chickpea. The seed production and delivery practices being employed are smallholder farmer-based practices that are environmentally friendly. For sustainable and reliable seed production and delivery systems in sub-Saharan Africa, a bold step is needed whereby the informal seed production entities are nurtured and upgraded into formal certified seed production ventures that deliver social and economic benefits to the promotors and the communities.

Aims: To appreciate the evolution of weight gain by malnourished children and factors associated to children underweight after the Positive Deviance/Hearth sessions. Study Design: Longitudinal study. Place and Duration of Study: Districts Ze and Lalo (Southern Benin), from May to August 2014 Methodology: This study was conducted on 98 children aged of 6-59 months who fully participated in Positive Deviance/Hearth (PD/H). During one month, four measurements of weight have been taken on the 77th, 84th, 91th, and 98th day after the beginning of PD/H. Questionnaire was administered to mother on environmental, hygiene practices, and food accessibility of household. Relation among factors of food accessibility, household hygiene, and child nutritional status was sought by an Analysis of Factorial Components. Results: The children who participated in 12 days of PD/H gained significantly 0.63 kg and 1.13 kg of weight in Lalo and Ze respectively (P<.001). From the 12th to 77th day after the end of PD/H, we noticed a significant weight loss from 10.54 to 10.09 kg in Ze and from 9.75 to 9.19 Kg in Lalo (P=.003). Prevalence of underweight children on the 77th day was 45.8% with 12.5% of severe case and 63.5% with 18.9% of severe case in Lalo and Ze, respectively. The severe underweight children were characterized by households where i) it rarely arrived to be without food ii) one member rarely have a day without eaten but iii) the drinking water is from well. Conclusion: On the 77th day after the PD/H, the children of our study had weight loss. Food accessibility and household hygiene are mainly the limited factors that could explain the degradation of the nutritional status of children and high prevalence of underweight. This first study conducted in Benin on PD/H approach is more exploratory and helps to appreciate this approach efficacy and sustainability.

This study aims to test whether exploitation affects tunas and tuna-like species displaying contrasting life history traits similarly. We first collected information on life history of 10 commercial Atlantic species and then compared this information using multivariate analysis. On one hand, tropical tunas are characterised by small to medium size, rapid growth, early age-at-maturity, long spawning duration and short life span. These species, therefore, display a rapid turnover, characteristic of r-selected species. On the other hand, temperate tunas display differing life history traits, i.e., large size, slow growth, late age-at-maturity, short spawning duration and long life span. The turnover of these species is slow and present characteristics similar to ‘K-selected’ species (with a conservative strategy adapted to a colder and more variable environment). We, then, selected the two tuna species displaying the most contrasting life histories, i.e., skipjack (SKJ) and bluefin tuna (BFT), and investigated their respective responses to various levels of exploitation, using simulation modelling. If fishing activity starts at age 1 (a situation which is close to the actual exploitation pattern), differences in life history traits make the BFT population much more fragile to exploitation and less productive than SKJ. However, if the fisheries only target adults, both SKJ and BFT populations are able to sustain high F. Spawning stocks and yields of BFT also display conspicuous long-term fluctuations, resulting from the combination of year-to-year variations in the recruitment and a long life span. This variability makes it difficult to detect overfishing or depletion risks in the BFT population. Because of its short life span, SKJ does not display such long-term variations in its SSB. Our simulations also showed that current management measures based on a minimum size limit are much more critical for BFT than SKJ. This difference stresses the importance of taking account of differences in life history traits into management measures.

This paper solves the problem of optimal sizing and locations of capacitors in radial distribution system using a new hybrid method combining a new stability index and a genetic algorithm to improve the loss, voltage and stability planes. The Bus Voltage Stability Index BVSI is used to determine the locations and the genetic algorithm GA to calculate the size. The GA-BVSI analytical-metaheuristic method, compared with existing methods, is more suitable and recommended for operators who are faced with the problem of sizing capacitors to improve the technical performance of their network. Keywords: Optimal sizing and locations; Capacitors; Radial distribution system; New stability index;Hybrid method.

AbstractIncreasing demand for land to ensure human food security in the future has already impelled agricultural production into marginal areas. The environmental conditions found there have a more pronounced impact on agricultural productivity than in the systems used so far under favourable conditions. In addition to this challenge, climate change is expected to increase the unreliability of weather conditions (through increased variability and occurrence of extremes) for farmers considerably. This unreliability is even more serious in developing countries’ farming system where food security is vulnerable. Current efforts in digitalization offer great possibilities to improve farmers` decision‐making processes. A wide range of online tools and smartphone applications is available to support both agricultural extension services and smallholder farmers alike. These apps are often parameterized and validated to certain environments and are troubled when applied to new geographical locations and different environmental conditions. We have conducted field trials to demonstrate potential methods to close knowledge gaps in the data background for one of these apps, RiceAdvice, concerning three key aspects: shifting of cropping calendar, adjustment of fertilizer management and genotype selection. Sites in Ethiopia, Madagascar and Rwanda were selected to represent altitudinal gradients, with overlapping elevations reflecting differences in temperature to enable cross‐country comparisons. Planting dates were distributed throughout three calendar years, with continuous iterative planting dates taking place in Madagascar, in‐ and off‐season planting dates in Rwanda with different fertilizer applications, and one planting date during each rainy season in Ethiopia with different management options. With these trials, we have been able to identify key data sets needed for the adaptation of agricultural decision support tools to new environments. These include the assessment of climatic constraints on innovations to cropping calendars (e.g. double cropping), informed selection of alternative varieties able to complete crucial parts of their phenological development to avoid temperature‐related stress inducing, for example spikelet sterility in rice in late development stages and the effectivity of potential innovations in fertilizer management strategies.

AbstractPhenological variability among populations is widespread in nature. A few predictive phenological models integrate intrapopulational variability, but none has ever explored the individual strategies potentially occurring within a population. The “pace-of-life” syndrome accounts for such individual strategies, but has yet to be explored under a phenological context. Here we integrated, for the first time, the slow-fast thermal strategies stemming from the “pace-of-life” into a mechanistic predictive framework. We obtained 4619 phenological observations of an important crop pest in the Bolivian Andes by individually following 840 individuals under five rearing temperatures and across nine life stages. The model calibrated with the observed individual “pace-of-life” strategies showed a higher accuracy in phenological predictions than when accounting for intrapopulational variability alone. We further explored our framework with generated data and suggest that ectotherm species with a high number of life stages and with slow and/or fast individuals should exhibit a greater variance of populational phenology, resulting in a potentially longer time window of interaction with other species. We believe that the “pace-of-life” framework is a promising approach to improve phenological prediction across a wide array of species.

Abstract. The management of agroecosystems plays a crucial role in the global carbon cycle with soil tillage leading to known organic carbon redistributions within soils and changes in soil CO2 emissions. Yet, discrepancies exist on the impact of tillage on soil CO2 emissions and on the main soil and environmental controls. A meta-analysis was conducted using 46 peer-reviewed publications totaling 174 paired observations comparing CO2 emissions over entire seasons or years from tilled and untilled soils across different climates, crop types and soil conditions with the objective of quantifying tillage impact on CO2 emissions and assessing the main controls. On average, tilled soils emitted 21 % more CO2 than untilled soils, which corresponded to a significant difference at P<0.05. The difference increased to 29 % in sandy soils from arid climates with low soil organic carbon content (SOCC < 1 %) and low soil moisture, but tillage had no impact on CO2 fluxes in clayey soils with high background SOCC (> 3 %). Finally, nitrogen fertilization and crop residue management had little effect on the CO2 responses of soils to no-tillage. These results suggest no-tillage is an effective mitigation measure of carbon dioxide losses from dry land soils. They emphasize the importance of including information on soil factors such as texture, aggregate stability and organic carbon content in global models of the carbon cycle.