GROWING-SEASON CHANGES IN THE CONCENTRATION AND DISTRIBUTION OF MACROELEMENTS IN WILLAMETTE RED RASPBERRY PLANT-PARTS

Nitrogen, P, K, Ca, Mg and Na concentrations and accumulations in Willamette red raspberry (Rubus idaeus L.) plant parts were measured in a field study to identify a potential plant-analysis-based method for evaluating site-specific fertilizer requirements. Dry matter and macroelements accumulated steadily in new canes over the season, increased early to a stable amount in floricane laterals and ripe berries, increased and then decreased in leaves and remained stable in stems. Macroelement accumulation patterns were generally similar to dry matter accumulations. The amounts of N and K that accumulated in ripe berries were similar and about eight times greater than P, Ca and Mg. Macroelement concentrations of floricane stems, laterals and berries were more stable than in leaves, making them potentially more suitable than leaves for developing tissue analysis for fertilizer recommendations.