Effects of Different Compound Treatments on Cold Resistance of Pitaya Plants Qian Luo, Tingting Wang, Lanlei Wu, Jirui Zhang, Gong Yan and Xian Luo E3S Web Conf., 131 (2019) 01112 Published online: 19 November 2019 DOI: 10.1051/e3sconf/201913101112