What is "destarch"

Destarching occurs when part of a plant is "deprived of starch, as by translocation".

It is also the process of eliminating starch reserves in a plant for experiments concerning photosynthesis. This is done by leaving the plant(s) in a dark place for a long period of time. Due to the lack of photosynthesis in this place, stored starch is used up, thus the plant is destarched.