how can we stop fragmentation

Fragmentation is a method of asexual reproduction found in some algae, lichens, Hydrilla, etc. We cant stop fragmentation. However, we can stop the growth of organism undergoing fragmentation by either using chemical or mechanical methods. For example: Fragmentation in Hydrilla can be prevented by using chemicals such as flouridone, endothall and copper compounds. While mechanical methods include cutting and harvesting of the plant.