The waxy coating on many leaves is important to the efficacy of agrochemicals as it can influence the uptake of these materials when they are sprayed onto the plant. Characterising these coatings is problematic because it is very difficult to remove them to determine, for example, their melting point by conventional thermal analysis. This is because of the complex morphology of leaves, which means that any scrapings from the surface would contain a variety of materials. Consequently, assigning transitions observed by DSC would be difficult. Removing the wax by dissolving it in solvent then recrystallising, destroys information about the original crystallinity of the coating.

Micro-TA provides a method of studying leaf wax on living leaves without significantly damaging them. It also makes possible the detection of variations in the character of the leaf surface in different areas and how chemicals deposited on the leaf affect this. Below is a result that shows the melting of a leaf wax, seen most easily in the micro-TMA signal (blue curve), on the succulent Crassula Argentea.