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