Seasonal leaf nutrient patterns and standard leaf nutrient levels for non-astringent persimmon in subtropical Australia

Seasonal changes in the leaf nutrient concentrations of two commercial cultivars of non-astringent persimmon, Izu (early maturing) and Fuyu (late maturing), were recorded over two seasons for two orchards in subtropical Australia. A leaf nutrient survey was also conducted over two years for eight high-yielding orchards, representative of the range of soil types in south-east Queensland. Overall, seasonal leaf nutrient patterns for both cultivars were similar to those previously established for temperate fruits. With the exception of boron, tentative leaf nutrient standards which have been set for subtropical Australia are closer to Japanese than New Zealand standards. High Mn levels in leaf (>2000 µg g⁻¹) and fruit (>100 µg g⁻¹) were recorded in orchards established on coastal podsolic soils. However, symptoms of “green blotch” disorder associated with Ca/Mn imbalances in the fruit were not recorded. The ideal time to sample leaves appears to be at anthesis, as leaf nutrient concentrations at this sampling time were found to be more stable than at later sampling dates. A major advantage of leaf sampling at anthesis, prior to root flushing, is that any detected nutrient deficiencies can be corrected in the current growing season.