EMERGENCE OF CARROT SEEDLINGS (DAUCUS CAROTTA L) FROM UNDER ARTIFICIAL OBSTACLES [French]

摘要

Carrot crop establishment is difficult and the percentage of emergence varies widely with soil properties, seedling environmental factors and seedling characteristics. This study took into account seed weight, sowing depth and seed-bed temperature, which influence the growth force of the seedling. The growth forces were measured in the laboratory (about 10 g or O.1 N). They were lower than the growth forces of other species and very variable for the same experimental conditions. The effect of the surface soil layer on the percentage of emergence was also studied. The theory of bending circular brittle plates allowed us to obtain a relationship between the characteristics of the obstacles and growth forces, which provided the possibility of designing an emergence model.