Thanks for sharing the Bamboo paper Maggi, it might bring some insights. This shows also a very interesting phenomenon, and the (inner) biological (chemical) clock hypothesis is surely a track to follow (extensively studied in human beings). The difficulty in modeling any of these biological mechanisms relates not only to multiple factors and interactions, but also into the dynamics of the process. Blooming peaks in Crocus sativus are sometimes spectacularly synchronized with the precision of a day. -- *Dr. Christian M. Lachaud**, PhD* https://www.facebook.com/christian.michel.lachaud