Objectives and context

Multiple agricultural challenges ...

World agriculture is facing the major challenges of increasing food supply for the growing world population while decreasing fertilizers and pesticides use and limiting the negative impact of climate change on crop productions.

In France, cropping systems have evolved over the last 50 years towards short simplified rotations often excluding grain legumes. A substantial change in the mode of agricultural production is required and an adaptation of varieties to low-input cropping systems is needed to meet the challenge of producing high quality food in a sustainable way. Legume use in arable rotations provides several significant ecological services that can help meeting the challenge of delivering safe, high-quality, and health-promoting food and feed in an economically and environmentally sustainable manner. As hosts of nitrogen-fixing bacteria, legumes allow better N management at the rotation level and reduce the need for N fertilizer, and pesticides. Together, they contribute towards reducing greenhouse gas emissions.

... But yields remaining very unstable

In addition to the previously quoted environmental benefits they provide, legume crops produce protein-rich seeds that are an excellent protein complement of cereal-based diets for humans and animals. Nevertheless, grain legumes are underused by European farmers mainly because of yield inconsistency, and Europe (EU) currently imports about 70% of its plant protein consumption.

Feed pea is currently the major grain legume crop in France. But the development of this crop has been hindered by yield instability, which contributes to farmers’ lack of confidence in pea as regards to their income. Different biotic and abiotic stresses are responsible for this yield instability, with varying impacts depending on the type of pea cultivated (winter or spring):

• diseases, especially Aphanomyces root rot due to Aphanomyces euteiches and ascochyta blight due to Didymella pinodes
• insect attacks (aphids, sitona, thrips, weevils)
• frost, drought or heat during flowering and seed filling

Pea damages due to Aphanomyces euteiches

Aphids on a pea pod

Bean weevil