Optimal management of tomato leaf pruning in rockwool culture

Abstract

Tomato yields and quality can be improved by the removal of some leaves attached to the tomato vine. The optimal degree of leaf removal varies based on environmental conditions, such as seasons. We investigated removal methods that are easily applicable to tomato cultivation during summer and winter harvesting periods. In the hot season experiment, four methods of leaf removal were tested: removal of all leaves more than 14 from the growing tip (Leaf-14), removal of leaves until only one leaf remained above the truss where harvesting begins (Start-H), removal of all leaves below the truss 7 weeks after flowers bloomed (7-Weeks), and removal of all leaves below the truss where harvesting was completed (End-H). Leaf removal did not affect the flowering rates very much, but influenced the harvest rates and yields greatly. The desirable harvest rate was 6–7 days per truss. Total yields decreased following leaf removal when the harvest rate was fast (3–4 days per truss). Thus, leaves must not be removed if the harvest rate is fast. The Start-H method was the optimal leaf removal method. The 7-Weeks method had results similar to those of Start-H, but its application was inconvenient. In the winter experiment, only three of the methods of leaf removal were tested: Leaf-14, Start-H, and End-H. Similar to the hot season experiment, the Start-H treatment had the best results in respect to yield and harvest rates. Therefore, the optimal leaf removal method is to remove all leaves until only one leaf remains above the truss where harvesting begins during either the hot or winter season.