Towards optimal designs for hedgerow olive orchards

An analysis of row height, row width, canopy slope, and alley width of hedgerow olive orchards was conducted to identify combinations that maximise productivity while allowing access to machinery for management. This objective requires maximising both the interception of incident solar radiation and its distribution over the canopy surface for productivity. For maximum productivity, all foliage must be illuminated above threshold values for the critical step in the shoot growth - floral initiation - flowering - fruit formation - fruit filling reproductive sequence. The key sites for adequate illumination are the bases of the canopy walls. For canopies with row height and alley width combinations that provide threshold illumination at the bases of the canopy walls, the area of productive foliage per unit orchard area is inversely related to row width because incident radiation received by broad canopy tops is better spread at smaller irradiance over more canopy wall. The analysis revealed that canopies of equal productivity can be formed with a range of combinations of height, slope, and alley width, and that optimal combinations are responsive to threshold values in the range 20 - 30% of incident radiation. Research is required to establish threshold values and the limits to row height and row width consistent with year-to-year production of reproductive shoots. The latter requires attention to cost and performance of machinery, the growth habit of the tree, and its response to pruning.