ISHS Acta Horticulturae 594: International Symposium on Foliar Nutrition of Perennial Fruit Plants
FOLIAR APPLICATIONS OF ACIDS WITH AND WITHOUT FESO4 TO CONTROL IRON CHLOROSIS IN PEAR |
| Authors: | P. Garcia-Laviña, A. Álvarez-Fernández, J. Abadia, A. Abadia |
| Keywords: | chlorophill, iron chlorosis, SPAD, pear, Pyrus communis |
| DOI: | 10.17660/ActaHortic.2002.594.24 |
| Abstract:
The effects of foliar applications of different compounds on the recovery of Fe-deficient pear trees from iron chlorosis have been studied in a 20 year-old orchard in 1995 and 1996. Chlorotic leaves were treated with acids to activate pre-existing iron pools and with Fe-containing compounds to increase leaf Fe concentrations. Leaf chlorophyll changes were monitored with a SPAD chlorophyll meter, before treatments were applied and then fifteen times during the following two months. Treatments were ascorbic, citric and sulphuric acids (2, 2 and 0.55 g•L-1 respectively), applied either alone or in combination with ferrous sulphate (500 mg Fe•L-1), ferrous sulphate alone, chelated Fe (119 mg Fe L-1 of Fe-DTPA) and water as a control. All treatments were applied to both sides of the leaf with a brush. Leaves were treated twice each year. None of the treatments caused a full recovery from Fe-deficiency chlorosis. Treatments containing Fe caused a marked re-greening whereas acid treatments applied alone were less effective. Among the acid treatments, the best re-greening effect at the end of the experimental period was caused by citric acid, whereas sulphuric and ascorbic acids were less effective. The acid plus FeSO4 treatments were not more effective than FeSO4 applied alone, whereas FeSO4 showed a similar re-greening effect to that obtained with Fe(III)-DTPA. In summary, foliar Fe applications could offer an alternative to control Fe chlorosis in pear, although further research is needed on the products, timing and doses that could be most suitable in real field conditions. | |
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