Trellising system and cane density affect yield and fruit quality of red raspberry

Trellising and cane density treatments were applied to vigorous raspberry (Rubus idaeus L.) cv. Titan plants in Southern Ontario to determine their effects on yield, yield potential, and canopy microclimate during the 1997 and 1998 seasons. The trellising treatments compared were hedgerow (control), V-trellis, and single-sided shift-trellis (shift-trellis). Cane densities (9, 16, 23, and 30 canes/m(2)) were established before budbreak each season. The treatments significantly affected yield and yield components. Path analysis indicated that interrelationships among yield components were significantly affected by trellising system. In the second season, plants trained on the V-trellis yielded more than did those in a hedgerow system, while those trained an a shift-trellis had the lowest yield because of a smaller fruiting framework. Fruit quality was lower on the shift-trellis than in the other two systems. These differences were related to light penetration into the three canopies. While an optimum cane density was not found for any system, the maximum cane density (30 canes/m(2)) produced the highest yields. Yield potential per cane decreased as cane density increased; however, the increase in cane number compensated for this decrease, resulting in an increase in total yield per unit area. Fruit quality also decreased as cane density increased, but cane density did not affect canopy microclimate.