  Mitscherlich's function is a well-known three-parameter non-linear regression
function that quantifies the relation between a stimulus or a time variable and
a response. Optimal designs for this function have been constructed only for
normally distributed responses with homoscedastic variances. In this paper, we
construct D-optimal designs for discrete and continuous responses having their
distribution function in the exponential family. We also demonstrate the
connection with D-optimality for weighted linear regression.
