GROWING-SEASON DRY-MATTER AND MACROELEMENT ACCUMULATIONS IN WILLAMETTE RED RASPBERRY AND RELATED SOIL-EXTRACTABLE MACROELEMENT MEASUREMENTS

Aboveground growth of Willamette red raspberry (Rubus idaeus L.) was destructively sampled and partitioned monthly in four growing seasons in 1980-1984 in south coastal British Columbia. This, together with chemical analyses of the plant parts and soil samples, was used to examine general macroelement dynamics. In each of the 4 yr, the plants (floricanes plus new canes) accumulated dry matter, N, P, K, Ca. Mg and Na rapidly during May to June and more slowly in September and October. Floricanes grew early in the season, with dry matter and macroelement uptake nearly complete by mid-summer then senesced after mid-summer with dry matter and nutrient loss. Most of this loss was leaves. New canes began to grow and take up macroelements later in the spring than floricanes and continued growth and uptake later into the fall. Growth and macroelement uptake patterns were inconsistent between years. A calculation, using October measurements, showed moderate quantities of N, P, K, Ca and Mg uptake by the plant on a unit area basis (107, 11, 102, 48 and 20 kg ha(-1), respectively). Since maximum cane growth and macroelement uptake occurred at two different times, a minimum of two samplings (mid-summer for floricanes and autumn for new canes) are required to more accurately measure total aboveground biomass production and macroelement uptake, The precise time of sampling should match the growth stage of the plant and not calendar date as growth patterns differed from year to year.