Modelling the distribution of isopropyl N-(3-chlorophenyl) carbamate [CIPC] in box potato stores

Summary

A numerical model has been produced to predict the distribution of deposits of the sprout suppressant isopropyl N-(3-chlorophenyl) carbamate [CIPC] in box potato stores. The model considers the movements of the CIPC by forced convection, sedimentation, natural convection and diffusion. Measurements have mostly shown high levels of CIPC on the top of the uppermost box, with levels decreasing towards the floor of the store. The model predicts this pattern and indicates that particle size, the temperature difference between the air inside and around the boxes, and the application rate of the chemical have a large effect on the levels and uniformity of CIPC deposits. Smaller particles (2 μm) can lead to better uniformity of distribution, but they are prone to natural convection effects which are difficult to control and they are slow to deposit which could lead to greater losses from the store.