New strategies to control iron chlorosis in citrus

The correction of iron chlorosis in trees grown on calcareous soils is normally achieved by the application of Fe (III)chelates such as iron ethylenediaminedi-ohydroxyphenylacetate (Fe-EDDHA) to the soil. This practice is very expensive and has to be repeated every year because iron is rapidly immobilized in the soil or leached out of the root zone. The responses of orange trees (Citrus sinensis (L.) Osb. cv. ‘Valencia Late’) grown on a calcareous soil to different foliar sprays were studied. In all the experiments, the recovery from iron chlorosis was evaluated with the SPAD-502 apparatus and the values converted to total chlorophyll concentration. The effects of treatments on themineral composition of flowers were studied. The residual effect of some treatments was also evaluated one year later. These results suggest that foliar sprays with Fe could help to avoid yield and quality losses caused by Fe chlorosis in citrus orchards. Furthermore, these treatments could be done with relatively cheap materials such as solutions containing Fe (II) sulphat