Diffusion of exudates

We calculated the response time based on three diffusion values ranging from 0.0018 cm² / day to 0.18 cm² / day to cover a wide range of possible values for the diffusion in an unknown homogeneous medium for unknown substances. Values less than 0.0018 have not been calculated because below this value the model calculated that the roots touch each other before the chemical signal has been transmitted. In fact, the root contact seems to be established in the modeling after 28 days. With a diffusion coefficient of 0.18, which is the maximum estimated value, the signal is transmitted after 11 days. Therefore, we can exclude the possibility that the change of direction of the roots of the experiment is caused by the transmission of a chemical signal because it could not reach the root segment before the change of direction which happened before one week.