Do dicotyledons generate greater maximum axial root growth pressures than monocotyledons?

Roots of dicotyledons (dicots) have often been observed to grow better in strong soil than monocotyledons; (monocots), and it has been suggested that this could be due to the dicots generating greater root growth pressures. Experiments were therefore carried out to measure the maximum axial root growth pressure (sigma(max)) in seedlings of monocots and dicots, Dicots did not generate greater sigma(max) than monocots: the mean for dicots was 0.41 MPa; the mean for monocots was 0.44 MPa.