Comparison of Two Organically Produced Tomato Cultivars After Micronutrients Enrichment

Iron (Fe) and zinc (Zn) are micronutrients commonly linked to nutritional deficits. Inadequate intakes of Fe can be linked to impaired cognition, weakness and fatigue or pathologies such as anemia. As for Zn, cell damages, stunting or increases in infection susceptibility can occur. In Portugal, an enrichment workflow with foliar sprays was performed, to increase Fe and Zn contents in two organically produced tomato cultivars. A total of 4 foliar sprays with a mixture of Maxiblend (concentrations of 1–7 kg/ha) and Zitrilon 15% (concentrations of 0.40–2.0 kg/ha), were applied during the production cycle. At harvest, mineral enrichment was assessed by µ-EDXRF, while total soluble solids (TSS) were measured with a refractometer. At harvest, Apple cultivar showed increases of 1.17–1.27 fold for Fe and 1.33–1.38 fold for Zn. For Chucha, Fe values increased by 1.10–2.05 fold, while Zn increased by 1.51–1.99 fold. Brix values at harvest ranged between 4.6 and 5.0° Brix and 4.2 and 4.9° Brix for Apple and Chucha cultivars respectively. Significant differences occurred only in Chucha. In conclusion, the applied agronomic approach can increase both minerals in both cultivars. For both cultivars T3 surpassed the toxicity threshold, limiting a continuous application. Complementary, both cultivars presented different responses to the applied concentrations, with Apple cultivar needing higher concentrations than Chucha to present mineral increases. The applied workflow did not negatively impact Brix values. Overall cultivar variability in organically produced tomatoes must be taken into consideration to maximize results.