The aim of this investigation was to study the effectiveness and physiological implications of sustainable strategies to correct Fe chlorosis in blueberries, based on Fe-heme applications or intercropping with graminaceous species. The experiment was conducted in a blueberry orchard established on a sub-alkaline soil. The Fe-heme applications increased shoot length without increasing the leaf chlorophyll concentration, gaseous exchange, and fruit yield components in comparison with control plants. On the other hand, intercropping with graminaceous species increased the leaf chlorophyll concentration, photosynthetic activity, and fruit yield, with similar effectiveness to the Fe-EDDHA treatment. However, this management technique reduced the shoot length and leaf N, P, and K concentrations in the plants. The results obtained highlight the potential of intercropping with graminaceous species as a sustainable management technique to correct Fe chlorosis in blueberry. Further studies will need to select new graminaceous species characterized by low nutrient requirements in order to optimize the effectiveness of this management technique.

The aim of this investigation was to study the effect of sustainable strategies to correct iron deficiency in blueberries, based on Fe-heme applications or intercropping with graminaceous species, on yield, and berry quality variables. The experiment was conducted in a blueberry orchard established in a sub-alkaline soil. The association with grasses increased the crop load and yield (only Festuca rubra), and decreased the skin/flesh ratio. In addition, these treatments increased anthocyanins as well as some hydroxybenzoic acids, hydroxycinnamic acids, flavanols, and flavonol concentrations in skins with a similar effectiveness as Fe-EDDHA, whereas the Fe-heme applications did not influence such parameters. Moreover, data revealed that the association with both grasses decreased the firmness of the berries, whereas none of the treatments assessed changed the soluble solids, pH, acidity, and the soluble solids/acidity rate compared to the control. These results suggest that Fe nutrition is crucial for yield and berry quality in blueberry, and that intercropping with grasses may be an effective and sustainable alternative to counteract Fe deficiency in blueberry, with a similar effect on berries to that achieved with Fe-EDDHA.