Neves, O.S.C. et al. 2005. Use of SPAD-502 in the evaluation of chlorophyll contents and nutritional status of herbaceous cotton to nitrogen, sulphur, iron and manganese. Pesquisa Agropecuaria Brasileira. 40, 5 (May 2005), 517–521. DOI:https://doi.org/10.1590/S1678-3921.pab2005.v40.6987.