VARIATION IN DRUPELET NUMBER AND WEIGHT IN PACIFIC-NORTHWEST RED RASPBERRIES

Fruit weight, drupelet number, drupelet weight and seed weight were me asured for five fruit per plot for raspberries in plantings establishe d at Puyallup, Wash. Primary fruit were harvested in the first and sec ond harvest seasons for raspberries in three plantings established in 1990, 1991 and 1992. For pooled data from the 124 plots sampled in thi s study, mean fruit weight fruit and drupelet weight increased from th e first to the second season, while there was no increase in drupelet number. The planting established in 1992 did not follow the same patte rn as the pooled data. In the 1992 planting the drupelet number increa sed, but drupelet weight did not increase from the first to the second harvest season. This may be the result of weather conditions at the t ime of fruit initiation or fruit development.