Crop diseases are a major threat to food security, but their rapid identification remains difficult in many parts of the world due to the lack of the necessary infrastructure. The combination of increasing global smartphone penetration and recent advances in computer vision made possible by deep learning has paved the way for smartphone-assisted disease diagnosis. Using a public dataset of 54,306 images of diseased and healthy plant leaves collected under controlled conditions, we train a deep convolutional neural network to identify 14 crop species and 26 diseases (or absence thereof). The trained model achieves an accuracy of 99.35% on a held-out test set, demonstrating the feasibility of this approach. Overall, the approach of training deep learning models on increasingly large and publicly available image datasets presents a clear path toward smartphone-assisted crop disease diagnosis on a massive global scale.

/pdf/using-deep-learning-for-image-based-plant-disease-detection-3ep7b222h5.pdf

Using Deep Learning for Image-Based Plant Disease Detection

The objective of this review is to explore and discuss the concept of local food system resilience in light of the disruptions brought to those systems by the 2020 COVID-19 pandemic. The discussion, which focuses on low and middle income countries, considers also the other shocks and stressors that generally affect local food systems and their actors in those countries (weather-related, economic, political or social disturbances). The review of existing (mainly grey or media-based) accounts on COVID-19 suggests that, with the exception of those who lost members of their family to the virus, as per June 2020 the main impact of the pandemic derives mainly from the lockdown and mobility restrictions imposed by national/local governments, and the consequence that the subsequent loss of income and purchasing power has on people's food security, in particular the poor. The paper then uses the most prominent advances made recently in the literature on household resilience in the context of food security and humanitarian crises to identify a series of lessons that can be used to improve our understanding of food system resilience and its link to food security in the context of the COVID-19 crisis and other shocks. Those lessons include principles about the measurement of food system resilience and suggestions about the types of interventions that could potentially strengthen the abilities of actors (including policy makers) to respond more appropriately to adverse events affecting food systems in the future.

/pdf/resilience-of-local-food-systems-and-links-to-food-security-3qqkd55ax7.pdf

Resilience of local food systems and links to food security - A review of some important concepts in the context of COVID-19 and other shocks.

Increasing global food demand, low grain reserves and climate change threaten the stability of food systems on national to global scales1–5. Policies to increase yields, irrigation and tolerance of crops to drought have been proposed as stability-enhancing solutions1,6,7. Here we evaluate a complementary possibility—that greater diversity of crops at the national level may increase the year-to-year stability of the total national harvest of all crops combined. We test this crop diversity–stability hypothesis using 5 decades of data on annual yields of 176 crop species in 91 nations. We find that greater effective diversity of crops at the national level is associated with increased temporal stability of total national harvest. Crop diversity has stabilizing effects that are similar in magnitude to the observed destabilizing effects of variability in precipitation. This greater stability reflects markedly lower frequencies of years with sharp harvest losses. Diversity effects remained robust after statistically controlling for irrigation, fertilization, precipitation, temperature and other variables, and are consistent with the variance-scaling characteristics of individual crops required by theory8,9 for diversity to lead to stability. Ensuring stable food supplies is a challenge that will probably require multiple solutions. Our results suggest that increasing national effective crop diversity may be an additional way to address this challenge. A greater diversity of crops at the national level increases the temporal stability of total national harvest, reflecting markedly lower frequencies of years with sharp harvest losses.

National food production stabilized by crop diversity

As antibiotic consumption grows, bacteria are becoming increasingly resistant to treatment. Antibiotic resistance undermines much of modern health care, which relies on access to effective antibiotics to prevent and treat infections associated with routine medical procedures. The resulting challenges have much in common with those posed by climate change, which economists have responded to with research that has informed and shaped public policy. Drawing on economic concepts such as externalities and the principal-agent relationship, we suggest how economics can help to solve the challenges arising from increasing resistance to antibiotics. We discuss solutions to the key economic issues, from incentivizing the development of effective new antibiotics to improving antibiotic stewardship through financial mechanisms and regulation.

The challenge of antimicrobial resistance: What economics can contribute

Rural livelihood diversification and household well-being: Insights from Humla, Nepal

Across the tropics, smallholder farmers already face numerous risks to agricultural production. Climate change is expected to disproportionately affect smallholder farmers and make their livelihoods even more precarious; however, there is limited information on their overall vulnerability and adaptation needs. We conducted surveys of 600 households in Madagascar to characterize the vulnerability of smallholder farmers, identify how farmers cope with risks and explore what strategies are needed to help them adapt to climate change. Malagasy farmers are particularly vulnerable to any shocks to their agricultural system owing to their high dependence on agriculture for their livelihoods, chronic food insecurity, physical isolation and lack of access to formal safety nets. Farmers are frequently exposed to pest and disease outbreaks and extreme weather events (particularly cyclones), which cause significant crop and income losses and exacerbate food insecurity. Although farmers use a variety of risk-coping strategies, these are insufficient to prevent them from remaining food insecure. Few farmers have adjusted their farming strategies in response to climate change, owing to limited resources and capacity. Urgent technical, financial and institutional support is needed to improve the agricultural production and food security of Malagasy farmers and make their livelihoods resilient to climate change.

https://royalsocietypublishing.org/doi/pdf/10.1098/rstb.2013.0089

Extreme vulnerability of smallholder farmers to agricultural risks and climate change in Madagascar

In many tropical countries, smallholder farmers are highly vulnerable to cyclones and experience significant crop losses, food insecurity and income loss when cyclones hit. Madagascar has one of the highest rates of cyclones globally and a population comprised primarily of smallholder farmers, yet there is little information on how Malagasy smallholder farmers prepare for and cope with the cyclones. We conducted interviews with 200 Malagasy smallholder farmers following the impacts of cyclone Giovanna (a category 4 cyclone that struck in February 2012) to understand how farmers prepared for the cyclone, how the cyclone impacted their livelihoods and what strategies farmers used to deal with these impacts. Most farmers prepared for the cyclone by storing clean water; some also secured their buildings and stored food and seeds. Cyclone Giovanna caused substantial damage to crops, stored grains and houses, and significantly reduced farmer food security. Farmers coped with the cyclone by replanting crop fields, rebuilding homes with local materials, reducing consumption of staple foods, harvesting wild foods and finding temporary work to buy food. Informal social networks were critical for providing food and rebuilding houses. There is an urgent need for governments, donors, and development organizations to reduce the vulnerability of Malagasy smallholder farmers to cyclones by improving early warning systems, increasing farmer preparedness for cyclones, creating formal safety nets to help farmers access food and essential supplies following cyclones, and promoting the use of adaptation measures to enhance the resiliency of smallholder farmers to future climate shocks.

Strategies of smallholder farmers for coping with the impacts of cyclones: A case study from Madagascar

To better understand and reduce the vulnerability of agrarian systems to climate change in Madagascar, the Project Team Climate Change Adaptation in Africa (CCAA) of Madagascar has adopted the method of Participatory Action Research (PAR). Briefly, PAR is a process in which members of a community or a group having a common problem to get together (a) to reflect on the strategy to solve the problem and (b) to set implement this strategy. It is an iterative and cyclical process of reflection, action, monitoring-evaluation and readjustment. PAR begins with a participatory diagnosis of the problem after which the group members define a shared vision, describing the situation to achieve. They plan strategies and actions to achieve this "ideal situation" and help each other in achieving them. After each action, the group consults in order to evaluate progress, to draw lessons and to re-plan a new action. Recherche action participative et dynamisme des agriculteurs malgaches face aux changements climatiques: cas de la Région d’Analanjirofo (côte est de Madagascar) ______________________________________________________________________________________________________________ 5 In the Analanjirofo Region, the Project has conducted PAR with a group of farmers from five villages in the rural commune of Ampasina Maningory and Ambodimanga II. Located on the northeast coast of the Island, this region has a tropical humid climate conducive to cash crops, particularly cloves and litchi, which are among the largest sources of foreign currency of Madagascar. The results of the PAR implementation has revealed that effective changes of various climatic parameters are experienced by those farmers, in particular the cyclones becoming more frequent and more intense since 1986. These climatic conditions have significant impacts on agrarian systems, making them more vulnerable. Clove trees are totally leafless and destroyed and didn’t have good harvest after three to five years. Consequently, this culture that has constituted the main source of income for farmers in the region decline significantly. PAR methodology was also used to involve farmers in finding solutions in their implementation and monitoring and evaluation, which is probably the source of dynamism in this process. The process is ongoing but early results are promising for adapting to climate change.

Recherche-action participative et dynamisme des agriculteurs face aux changements climatiques : cas de la région Analanjirofo (Est de Madagascar); publication scientifique sur la "Recherche-Action Participative"

Library has French version: Madagascar : les strategies d'adaptation aux cyclones dans la region d'Analanjirofo, Madagascar

R. Rabarijohn

Papers

Extreme vulnerability of smallholder farmers to agricultural risks and climate change in Madagascar

Strategies of smallholder farmers for coping with the impacts of cyclones: A case study from Madagascar

Recherche-action participative et dynamisme des agriculteurs face aux changements climatiques : cas de la région Analanjirofo (Est de Madagascar); publication scientifique sur la "Recherche-Action Participative"

Adapting to Cyclones in Madagascar’s Analanjirofo Region