lag time plotting issue

[sambra95]

1. when phenomenological richards model is used the lag time does not seem to match the plotted lag time. this could also be the case for other methods where the lag time is lambda
2. The plotted tangent should no extend beyond the exponential phase green boundary

[sambra95]

looks like N0 is taken from the fitted curve but the guidelines and tangent have their minimum values set by the actual minimum datapoint