HEDGEROW VS. STANDARD HIGH-DENSITY MANAGEMENT SYSTEMS FOR WALNUTS
An attractive alternative to hand pruning to maintain productivity of closely planted orchards is mechanized tree hedging. Experimental results have shown that once walnut orchards become crowded, hedging to allow light between trees does not effectively alleviate the condition. Mechanical hedging, however, may be valuable in maintaining tree size and production of precocious lateral-bearing varieties where trees have not yet become crowded.
Hedgerow planting of lateral-bearing walnut cultivars is another method to increase early returns on investments and develop a more efficient high-density management system for walnuts. The trees are trained to produce a continual wall of foliage and nut-producing shoots in response to mechanical side hedging. The wall not the single tree becomes the management unit in the orchard. Higher early yields and the use of mechanized hedging machines for pruning are the major advantages. High initial cost is the primary disadvantage due to the increased number of trees/ha.