Climatic accident (Brittle collar)

Young lettuce grown in the field are particularly sensitive to wind. Their collar is particularly stressed when the wind blows continuously. The plant tissues very locally undergo mechanical stresses and friction with the surrounding soil and set up corky scar foundations. These no longer allow the tissues to develop normally due to their loss of elasticity. The collar is thus gradually "strangled" and breaks easily when the plants have reached a certain size (figures 1 to 3) ( brittle collar ). We can assume that these suberized tissues, sometimes spongy, can be invaded by secondary microorganisms amplifying the phenomenon of suberization and sometimes giving the tissues a darker color.

It is difficult to avoid this very natural problem. Preferably, plots are less exposed to the wind.