Diurnal variation of melatonin content in sweet cherry leaves Tian Shen, Xin Wang, Hongxia Tu, Xuefeng Zhang, Fangren Liu, Gui-hong Zhou, Dong Liang and Hui Xia E3S Web Conf., 145 (2020) 01022 Published online: 06 February 2020 DOI: 10.1051/e3sconf/202014501022