@INBOOK {WATANABE:1997d, title = {Evaluation methods for drought tolerance of cowpeas}, author = {Watanabe, I. and Hakoyama, S. and Terao, T. and Singh, B. }, editor = {Singh, B. and Mohan-Raj, D. R. and Dashiell, K. and Jackai, L. }, year = {1997}, type = {Advances in cowpea research}, pages = {141--146}, publisher = {International Institute of Tropical Agriculture (IITA), Japan International Research Center for Agricultural Sciences (JIRCAS)}, address = {IITA, Ibadan, Nigeria}, }