4Alfred E. Hartemink,M. Johnston,J.N. O’Sullivan,S. Poloma.??Nitrogen use efficiency of taro and sweet potato in the humid lowlands of Papua New Guinea(J)Agriculture, Ecosystems and Environment . 2000 (2)
5L. A. Wilson.??Stimulation of adventitious bud production in detached sweet potato leaves by high levels of nitrogen supply(J)Euphytica . 1973 (2)
6Zhang H,Jennings A,Barlow P W,et al.Dual pathways for regulation of root branching by nitrate. Proceedings of the National Academy of Sciences of the United States of America . 1999
