Impact of climate and diseases on pea yields: what perspectives with climate change?

For farmers, pea crop is characterized by a large yield variability between years, between areas, and even between fields in a same small area in a given year. In dry year, spring pea crops are mostly affected by water stress and high temperature but significant yield losses can also be caused by a root disease, Aphanomyces euteiches, particularly during wet years. Winter pea can escape partially from drought, high temperature, and root disease during the reproductive phase of the crop cycle. However, when winters are mild, without progressive negative temperatures, which provide frost acclimation, available cultivars are not resistant enough to frost and are susceptible to aerial diseases such as ascochyta blight and bacterial blight (Pseudomonas syringae pv. pisi), thus leading to yield losses. A better adaptation of sowing dates, an improvement of lodging resistance and a limitation of the sowing density can limit the development of ascochyta blight for winter pea crops. For spring pea, an increased use of Aphanomyces soil test could avoid to sow the crop in infested fields. Current spring pea varieties are the result of changes in plant architecture including the reduction of 1000-seed weight that have led to yield losses by increasing the fragility of variety facing these stresses. The development of a pea crop model, simulating the effect of various stress encountered on winter and spring pea crops, can help to better define the regions adapted for the production of these two types of cultivars, and also help the breeders to better define and choose which trait to improve in order to increase the pea productivity and yield stability. National and European projects are in course to breed new varieties more adapted to different stresses