Estimation of fruit weight by cane traits for various raspberries (Rubus ideaus L.) cultivars

Raspberries are an important commercial fruit crop, widely grown in all temperate regions of the world. The raspberries contain significant amounts of polyphenol antioxidants such as anthocyanin pigmentslinked to potential health protection against several human diseases. The aim of this study was to estimate fruit weight by their cane traits (the number of canes, cane height, cane diameter, and caneyield) for Aksu Red, Canby, Heritage I, Heritage II, Holland Dwarf, Nuburg, Rubin, Summit, Tulameen, and Willamette cultivars grown in Central Anatolia region during 2002 - 2006. For this aim, average fruitweight (dependent variable) for each cultivar was estimated by independent variables such as the number of cane, cane height, cane diameter, and cane yield using Multiple Regression Analysis (MRA).The results clearly show that cultivars having the best fit (giving the best R2 values and the lowest RMSE) in MRA were: Holland Dwarf (99.64%), followed by Heritage I (99.06%), Summit (98.6%) Aksu Red(92.82%), Willamette (92.68%), Heritage I (90.46%), Rubin (90.28%) and Canby (85.45%). Multiple Regression Modeling gave good results for these cultivars. However, R2 values of these cultivars werefound higher (better fit) than those of Nuburg and Tulameen cultivars. It was concluded that the number of canes had significant negative effect on fruit weights of Heritage (P < 0.05) and Summit (P < 0.001)cultivars, but significant positive effect on only fruit weight of Rubin cultivar (P < 0.05). Cane height had significant positive effect on fruit weights of Aksu Red (P < 0.001), and Summit (P < 0.001) cultivars,while it had significant negative effect on fruit weights of Canby (P < 0.05) and Heritage I (P < 0.05). Cane diameter had significant positive effect on fruit weights of Aksu Red (P < 0.001), Heritage I (