Malavolta, E. and Carvalho, J.G. de 1982. Foliar diagnosis in sugar cane: VI - effect of rainfall on the foliar N, P and K of the plant cane . Anais da Escola Superior de Agricultura Luiz de Queiroz. 39, 1 (Jan. 1982), 101–108. DOI:https://doi.org/10.1590/S0071-12761982000100006.