In populations of apple trees (Malus pumila Mill) affected by iron chlorosis, the floral analyses permit to establish relationships between the iron concentration in flowers and the chlorophyll content in leaves at 60 and 120 days after full bloom. The relationships between both parameters were highly significant with correlation coefficients of 0.603*** and 0.872*** respectively. As from previous research with peach trees, these high correlations allowed permitted us to predict at a very early stage, the appearance of the iron deficiency and its intensity. In our experimental conditions, the first visual symptoms of the iron chlorosis appear in apple leaves with floral iron concentrations below 310 ppm in dry matter.