Heritage', 'Titan', and 'Boyne' red raspberries ( Rubus idaeus L.) were grown for 3 years and plots were sampled annually for changes in growth. 'Heritage' is a primocane- and floricane-fruiting, strongly suckering cultivar; 'Boyne' is a floricane-fruiting, strongly suckering cultivar; and 'Titan' is a floricane-fruiting, weakly suckering cultivar. Each year in October, plants of each cultivar were dug from two 0.5-m 2 plots in each of four rows, separated into roots, crowns, canes (primocanes were harvested in October and floricanes were harvested in July), and leaves, and dried. Fruit were harvested, yields were recorded, and dry weights of subsamples were used to estimate total fruit dry weights. 'Heritage' fruit included the primocane and floricane harvests. 'Heritage' was more yield-efficient than 'Boyne' or 'Titan' in that it allocated a higher percentage of total dry weight to fruit and a lower percentage to vegetative parts. Although 'Titan' had fewer canes, cane diameter and length were greater. 'Boyne' allocated higher percentages of total dry weight to roots than other cultivars. The percentage of total dry weight allocated to fruit was similar for 'Boyne' and 'Titan' in 1992, but lower for 'Boyne' in 1991. Within the cultivars tested, phenotype for suckering did not indicate productivity. Red raspberries spread by adventitious shoots or root suckers. In nature, this characteristic allows them to colonize an open area quickly and fruit before being out-competed for light by later successional, taller species (Whitney, 1982). In domestic produc- tion, this habit is not valued since narrow rows are desired for good light penetration (Braun et al., 1989; Wright and Waister, 1986) and ease of picking (Lawson and Wiseman, 1979). New cultivars have been selected that present less of a problem to the grower by producing fewer root suckers. Root suckers shade the floricanes (Fernandez and Pritts, 1993; Wright and Waister, 1984 ) and make picking difficult (Lawson and Wiseman, 1979, 1983), although they do not actually take photosynthate from the floricanes (Fernandez and Pritts, 1993). Growth regulators have been used to burn off the early root suckers to reduce competition with floricanes (Crandall et al., 1980), but this method is not practiced universally. New cultivars have been selected that produce fewer root suckers, potentially reducing cane competition and resulting in fewer canes with larger diameters; however, these new cultivars do not neces- sarily produce greater yields. Canes of greater diameter and length yield better on a per-cane basis but not on an area basis if density is low (Crandall et al., 1974). Suckering cultivars may allocate more C to producing suckers and less to fruit, with a resulting increased intracane competition and reduced yield per cane. Or, the greater number of canes produced by suckering may increase fruit production on an area basis. The objective of this study was to determine how red raspberries with different phenotypes for suckering partition C between fruit and vegetative parts. Grain breeders have used dry weight partitioning to determine which cultivars maximize yields (Evans, 1975). This technique can offer much insight into productivity.