On the evolution of intrinsic curvature in rod-based models of growth in long slender plant stems

In many applications of rod theories as models for plant stem growth and development, it is necessary to allow the intrinsic curvature and flexural stiffness of the rod to evolve. In the present paper, the application of evolution equations for these quantities is examined and a new evolution equation for the intrinsic curvature is proposed. To illustrate the new evolution equation, several examples of the evolution of rods in the presence of external forces and tip growth are presented. Growth in plants frequently results in residual stresses and the compatibility of rod models with these fields is also discussed.