Influence of Sampling Time on Elemental Composition of Strawberry Leaves and Petioles1

Concentrations of 13 macro and micro elements in leaves and petioles of 3 strawberry ( Fragaria × ananassa Duch.) cultivars were determined biweekly during the growing season. Concentrations of most elements changed rapidly during flowering and fruiting. For most elements, leaf analysis was preferred since markedly greater concentrations occurred in leaves than petioles. These sampling dates and tissue factors, and significant cultivar differences must be considered in interpreting foliar analysis data. Concentrations were relatively stable during the 6 weeks following harvest and this period appeared optimum for sampling.