PROGNOSIS OF IRON CHLOROSIS IN APPLE-TREES BY FLORAL ANALYSIS

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