Fig. 1. (A) Temporal profiles of green vegetation fraction of the fields studied, during the 2001 and 2002 growing seasons. (B) Temporal progression of total chlorophyll content in top-collar maize leaves during the growing season of 2002. Error bars correspond to one standard deviation. Accumulated growing degree days (AGDD) were calculated starting from 1 May. Inset: Relation between total chlorophyll content in mg/m² and chlorophyll index of 70 maize leaves {Chl = 723.04 x [(_NIR/_{Red Edge}) – 1] – 10.76; r² = 0.93; p < 0.001}. The coefficients obtained from this equation were used to calculate leaf chlorophyll content of top-collar leaves along the growing season of 2002.