Boron (B) is an essential microelement for plants, being its deficiency the most frequent
micronutrient disorder in olive tree. The main functions of boron are related to cell wall
strength and development, membrane function, cell division, fruit and seed development,
water relations, sugar transport and hormone development. The study conducted in
Bragança (Northeast Portugal), under rainfed conditions, shows that application of Bfertilizer
decreased the symptoms of oxidative stress on leaves, both in summer and, with
higher extent, in winter. In fact, B-treated trees presented lower electrolyte leakage, in a
closely association with higher concentration of total thiols. Moreover, boron increased the
concentration of soluble sugars, while decreased the accumulation of starch in both
seasons. Meanwhile, total soluble proteins and total phenols levels were higher in Bfertilized
plants during the summer period, whereas in winter, after frost events, the
concentration of phenols was higher in B-starved trees. The chemical composition of fruits
at final harvest revealed that B-supply increases the soluble sugars and the pulp ash
content, decreases organic matter and dietary fiber, whilst the crude protein concentration
was similar between treatments. Thus, the present study showed that addition of Bfertilizer
affects the metabolism of olive tree and give new insights about the effect of boron on plant physiology and biochemistry that will help to refine the improvement in Bfertilizer
recommendations for olive growing areas.info:eu-repo/semantics/publishedVersio
