Cane- and Spur-Pruned Pinot noir Results in Similar Fruitfulness, Yield, and Grape Ripeness under Cool Climate Conditions

Abstract

Summary Goals: Oregon Pinot noir growers prefer head training and cane pruning to cordon training and spur pruning, referred to herein as cane and spur pruning, respectively. With decreasing labor availability and increasing production costs, growers are interested in transitioning to spur pruning to improve vineyard economics because spur pruning requires less manual labor and is easier and more economical to mechanize than cane pruning. However, they are hesitant to adopt spur pruning because of fears of reduced and inconsistent yields, as they believe Pinot noir has unfruitful basal buds. We conducted a two-year field trial to compare Pinot noir cane- and spur-pruned vine productivity from dormancy to harvest in a vineyard trained to a unilateral Guyot training system where vines were head trained and cane pruned to one 10-node cane and one two-bud renewal spur or cordon trained and spur pruned to six spurs of two nodes per spur. Key Findings: Primary bud fruitfulness was no different between pruning methods. Node position was important for dormant compound bud fruitfulness. The first, second, and third count nodes from the base of a cane or spur were fruitful, but node positions 4 and 5 had 11% higher fruitfulness. There was higher compound bud fruitfulness and greater inflorescence primordia size in compound buds of dormant canes with greater weight and diameter, regardless of pruning method. Pruning method did not affect vine phenology, yield, or harvest grape ripeness (Brix, pH, and titratable acidity [TA]). Impact and Significance: Our study found no yield or grape ripeness differences between cane- and spur-pruned Pinot noir in a unilateral Guyot training system. Therefore, spur pruning is an option for producers who wish to reduce dormant pruning labor and who consider adopting mechanization for further cost savings. Additional shoot-thinning passes may be required in spur-pruned vineyards, since the older cordon wood resulted in greater growth of adventitious shoots in spring compared to cane-pruned vines.