Covid-19 management by farmers and policymakers in Burkina Faso, Colombia and France: Lessons for climate action.

CONTEXT: During crises, adaptation or recovery measures or plans at local or national scales may not necessarily address longer-term or structural problems such as climate change mitigation. OBJECTIVE: This article describes farmers and policymakers' responses to mitigate the adverse effects of Covid-19 on the agricultural sector. We then assess the responses' possible effects on greenhouse gas (GHG) emissions. METHODS: The study is based on surveys conducted with farmers, traders, and extension staff in Burkina Faso, Colombia, and France, and literature. We used the Cool Farm Tool calculator to assess GHG emissions associated with fertilizer production, crop production and produce transportation to international markets for the three main cash crops in the three countries. RESULTS AND CONCLUSIONS: We identified contrasting responses by the agricultural sector mostly driven by changes in the consumption patterns at local or international levels. We also identified contrasting state responses to mitigate Covid-19. These responses at farm and policy scales led to similar trends in decreasing carbon dioxide (CO2) emissions across the studied countries. However, none of the studied countries linked Covid-19 response measures to long-term climate change mitigation actions. Therefore, an opportunity to sustain Covid-19 induced short-term decreases in GHG emissions was overlooked. SIGNIFICANCE: Analyzing the impacts that Covid-19 had on agricultural systems and the decision taken by policymakers to handle its direct and indirect effects can help society draw lessons on how to improve climate action.

Source of Hyalesthes obsoletus Signoret planthopper (Hemiptera: Cixiidae) in southern France and potential effects of landscape.

Cixiid planthoppers are considered of major economic importance, as they can transmit phytoplasmas responsible for many plant diseases. While thorougly studied in vineyards, the epidemiology of stolbur phytoplasma, transmitted by Hyalesthes obsoletus Signoret, was rarely investigated on minor crops as lavender, where it leads to 'yellow decline' disease and large economic losses. The objective of this paper is to understand the effect of the local landscape characteristics on the presence and density of H. obsoletus in the 'Plateau de Valensole', southern France. Potential host plants of H. obsoletus were surveyed in three contrasted zones (in terms of crops and disease intensity), by uprooting plants and capturing adults in emergence traps. The localization and potential movements of H. obsoletus from the host plants towards lavandin (infertile hybrid of lavender) were determined using yellow sticky traps. Clary sage plants were found as major hosts of H. obsoletus. Flying insects were also caught in fields of lavandin, although emergence traps and plant uprooting did not confirm this crop as a winter host, i.e., as a reservoir for the insect. Based on one zone, we showed that attractiveness may depend on crop (clary sage or lavandin) and on its age, as well as on the distance to the supposed source field. These results suggest that clary sage could be an important host of H. obsoletus, whose density largely varies between zones. Genetic studies would be required to confirm the role of clary sage in the dissemination of yellow decline of lavandin.

Effects of halving pesticide use on wheat production.

Pesticides pose serious threats to both human health and the environment. In Europe, farmers are encouraged to reduce their use, and in France a recent environmental policy fixed a target of halving the pesticide use by 2018. Organic and integrated cropping systems have been proposed as possible solutions for reducing pesticide use, but the effect of reducing pesticide use on crop yield remains unclear. Here we use a set of cropping system experiments to quantify the yield losses resulting from a reduction of pesticide use for winter wheat in France. Our estimated yield losses resulting from a 50% reduction in pesticide use ranged from 5 to 13% of the yield obtained with the current pesticide use. At the scale of the whole country, these losses would decrease the French wheat production by about 2 to 3 millions of tons, which represent about 15% of the French wheat export.