ISHS Acta Horticulturae 721: V International Symposium on Mineral Nutrition of Fruit Plants
MINERAL CONTENT OF DIFFERENT APPLE CULTIVARS IN RELATION TO FRUIT QUALITY DURING STORAGE |
| Authors: | C. Moggia, J.A. Yuri, M. Pereira |
| Keywords: | nutrient deficiency, nutrient toxicity; lenticel breakdown; stem-end splitting, bitter pit |
| DOI: | 10.17660/ActaHortic.2006.721.36 |
| Abstract:
Since 1996 this Center has carried out several studies to determine the content of mineral elements in skin and flesh of different apple cultivars. Centro de Pomáceas has found relationships of some of them with the incidence of physiological disorders in fruit during storage. The most relevant elements involved have been Ca and its antagonists (Mg and K). Not only a deficit, but also an excess of these nutrients has been associated with diverse symptoms: bitter pit, lenticel breakdown and stem-end splitting. Calcium toxicity has been related to postharvest applications of the element, including lenticel injuries (depression and browning). The effect of Ca concentration: 0% (water), 1.5 and 3.0% CaCl2, as a drench, and fruit drying speed (immediate entrance of fruit to cold storage or one d delay at room temperature), was determined on incidence of lenticel breakdown. Cultivars tested were: Royal Gala, Jonagold, Granny Smith and Braeburn. Results indicated that injury incidence affected between 20% (Granny Smith and Braeburn) and 60% (Royal Gala) and were increased with higher Ca concentration. Drying speed had no effect on the occurrence of damage. On the other hand, Ca deficiency is responsible for bitter pit; i.e. brown depressions located towards the calyx-end of the fruits. In this case, Ca levels have fluctuated between 170 and 400 ppm on skin, and between 80 and 300 ppm on fruit flesh. In addition, and given its high association with other nutrient imbalances, ratios for N/Ca, Mg/Ca and K/Ca have been calculated. The injury known as stem-end splitting, important in Royal Gala apples, would be apparently associated with K level in the tissue, since this was the only element that had a significantly higher concentration in injured fruits. | |
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