Comparison of Mechanical and Manual Cane Pruning Operations on Three Varieties of Grape (Cabernet Sauvignon, Merlot, and Prosecco) in Italy

This study reports a functional, economic, and qualitative analysis of mechanical cane pruning in comparison with cane pruning performed manually and after a passage with a pre-pruner. In particular, tests were performed on two vine varieties in a Double Guyot training system (Prosecco and Merlot) and one variety in a Guyot system (Cabernet). In Cabernet, the comparison took into account all three operations, while in Prosecco and Merlot only mechanical and manual cane pruning were compared. Compared to the pre-pruner and manual pruning, mechanical pruning is affected by fixed work phases, which leads to variation in the working time with the length of the row. For the pre-pruner and manual pruning, the working time is independent of the row length. Where the vegetation is more expansive and a large number of shoots need to be removed, the advantages of mechanical pruning are more obvious. The most significant differences between mechanical and manual pruning were found in Double Guyot for the low-density variety (Prosecco). In Cabernet (Guyot), the limit for no difference between mechanical and manual pruning is a row length of 93 m, and the limit for no difference between mechanical pruning and the pre-pruner is a row length of 116 m. In economic terms, if the rows are 400 m long, then the surface area suitable for mechanical pruning is 10 to 11 ha for all three varieties. There was no visible damage to the fruit branches with the mechanical pruner, but some damage occurred to wires with a diameter of less than 1.8 mm. The percentage of residue left on all three varieties was very low.