The effectiveness on controlling Fe chlorosis in orange trees grown on calcareous soils was tested. The treatments were Fe(II) sulfate (500 mg Fe L−1), sulfuric acid (0.5 mM H2SO4), Fe(III)-chelate (Hampiron 654 GS, 120 mg Fe L−1) and distilled water as a control. A non-ionic wetting agent was used in all treatments. The use of frequent foliar sprays alleviated Fe chlorosis in orange trees. Sprays of Fe(II) sulfate increased the concentrations of chlorophyll, Fe and zinc in leaves and improved fruit size and quality compared to fruits of control trees. Sprays of Fe(III)-chelate also increased leaf chlorophyll and Fe concentrations and improved fruit quality, but did not increase fruit size. Sprays of sulfuric acid alone slightly increased leaf chlorophyll and Fe concentrations, without improving fruit size and quality. These results suggest that foliar sprays with Fe could help to avoid yield and quality losses caused by Fe chlorosis in citrus orchards. Furthermore, these treatments could be done with rel...

Crop load can influence fruit quality in several horticultural species. The aim of the present study was to determine the effect of different concentrations of calcium on crop quality traits in three short-day strawberry (Fragaria x ananassa Duch.) cultivars ('Ventana','Camarosa' and 'Candonga') and to assess the relationships between crop load and quality parameters. The studies were conducted using a hydroponic system in a greenhouse. Calcium was added as Ca(NO3)(2) at 2 mM, 3 mM, 4 mM and 5 mM. A completely randomized block design (4 Ca concentrations x 3 cultivars) with three replicates was used. Each replicate consisted of 12 plants grown in polyethylene bags (100 cm x 18 cm x 3 cm) filled with coconut peat. Titratable acidity, total soluble solids and firmness were measured throughout the experimental period. Calcium application had no effect on fruit quality attributes but the genotype effect was clear. At the end of the experiment (28th May, 2008), titratable acidity was positively related to the fresh weight of above-ground biomass and number of leaves respectively in the 'Ventana' and 'Camarosa' cultivars. Higher values of total soluble solids were found at low crop load in 'Ventana' but in 'Camarosa' this relation was not found. In 'Candonga', higher total soluble solids were linked to crop load. In 'Ventana', titratable acidity significantly decreased as crop load increased, and in 'Camarosa' high values of titratable acidity were found at different values of crop load. 'Ventana' seemed to be more sensitive to the effects of crop load patterns. Genotype was an important factor in determining fruit quality parameters. (C) 2011 Elsevier B.V. All rights reserved