THE EFFECTS OF PRUNING AND TREE DENSITY ON LEAF PHYSIOLOGY AND YIELD OF HAZELNUT

C. Kempler, J. Todd Kabaluk, P. M.A. Toivonen
The effect of pruning and tree density on leaf physiology and yield were studied in a nine-year-old hazelnut (Corylus avellana L. cv. Barcelona) orchard. Because most of the nut production occurs in the upper two-thirds of trees, the purpose of this study was to increase the productivity in the lower region by enhancing the interception of solar radiation. The experiment included a factorial combination of two spacing treatments (3.7 x 5.5 m - high density or 5.5 x 7.3 m - low density) and two levels of pruning (pruned - open center or unpruned - maintenance pruning). The treatments were applied in January 1991.

Open center pruning reduced yields per tree by 18% in 1991. Yield per hectare was also reduced by pruning and by increased spacing. Pruned and unpruned trees grown at low density showed a 24% and 11% yield increase, respectively, over high density trees. From 1991 to 1992, nut production in the lower canopy decreased in high density unpruned trees, while nut and cluster production increased in both high density and pruned trees. Pruned and low density trees had a greater leaf dry weight per unit area (Wa), leaf nitrogen content, and lower relative chlorophyll fluorescence (CF).

Kempler, C., Todd Kabaluk, J. and Toivonen, P. M.A. (1994). THE EFFECTS OF PRUNING AND TREE DENSITY ON LEAF PHYSIOLOGY AND YIELD OF HAZELNUT. Acta Hortic. 351, 481-488
DOI: 10.17660/ActaHortic.1994.351.52
https://doi.org/10.17660/ActaHortic.1994.351.52

Acta Horticulturae