Abstract

RAZETO, Bruno  and  PALACIOS, Johanna. Effect of iron chlorosis on avocado (Persea americana Mill.) fruit size and oil concentration. Agric. Téc. [online]. 2005, vol.65, n.1, pp. 105-111. ISSN 0365-2807.  doi: 10.4067/S0365-28072005000100013.

In order to determine the effect of iron chlorosis on fruit size and oil content, of avocado (Persea americana Mill.) a trial was conducted on a 22-year-old orchard cv. Hass located at Quillota, Chile (32º51’ S lat., 71º6’ W long.). Twelve trees with different degrees of iron chlorosis were selected, normal green foliage and others highly chlorotic. Fifteen fruit and 30 leaves per tree were taken on August 30. In this samples iron concentration was determined by spectrophotometry. Color by tri-stimulus colorimetry and chlorophyll concentration by ethanol extraction and spectrophotometer absorbance were measured on leaves and fruit peels. Fruit weight and oil content were measured by petroleum ether extraction. Fruit from normal trees had an iron concentration of 13.8 mg kg^-1 (P £ 0,05) higher than that of chlorotic trees. A high correlation between the chlorophyll level of leaves and fruit peels was found (R² = 0.74). The leaf chlorophyll concentration was also highly associated with the fruit weight (R²= 0.93) and oil content (R² = 0.68).A similar relation was found between the fruit peel chlorophyll concentration and the fruit weight (R² = 0.70) and its oil content (R² = 0.86). It is concluded that iron chlorosis diminished fruit size and oil concentration in avocados.

Keywords : iron deficiency; chlorophyll; cv. Hass.