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 Will amette red raspberry (Rubus idaeus L.) plant parts were measured in a field study to identify a potential plant-analysis-based method for ev aluating site-specific fertilizer requirements. Dry matter and macroel ements accumulated steadily in new canes over the season, increased ea rly to a stable amount in floricane laterals and ripe berries, increas ed and then decreased in leaves and remained stable in stems. Macroele ment accumulation patterns were generally similar to dry matter accumu lations. 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 stab le than in leaves, making them potentially more suitable than leaves f or developing tissue analysis for fertilizer recommendations.