Manganese Deficiency in Peach Trees:

In previous studies was pointed out that it may be possible to detect subclinical manganese deficiencies in the field before visual symptoms have developed. In this work, by in situ fluorescence measurements, we demonstrate that it is possible to predict, at the beginning of the season, which trees will develop manganese deficiency several months later. Fo/Fm ratio of young manganese deficient leaves without visible symptoms was higher than the measured in the equivalent control leaves. More than 80% of concordance, between the initial measurements and the symptoms lately developed was reached. This facts made us to believe that it could be possible to predict manganese deficiency just when the first leaves appeared and therefore apply effective correcting measures to prevent manganese deficiency in peach trees. Economical repercussion of manganese deficiency, in terms of yield and fruit characteristics, are also discussed. Index Key