Pruning and Training of Young Walnut Trees

Walnut trees are highly valued for their nutritious nuts and significant economic worth. However, to maximize yield and ensure healthy growth, it is crucial to implement proper pruning and training techniques. Pruning and training young walnut trees are essential practices to develop a strong tree structure, increase fruit production, and enhance resistance to diseases and pests.

Understanding the natural growth habits and biological characteristics of walnut trees is fundamental to applying these techniques effectively. If young walnut trees are not pruned and trained correctly in their early years, they may face structural issues and decreased productivity in the future. Thus, guiding young walnut trees with appropriate pruning and training methods is key to long-term success.

Pruning helps shape the trees, improves light and air circulation, and reduces the risk of diseases by removing excess branches. Training, on the other hand, focuses on developing a strong central leader and balanced scaffold branches. Together, these practices ensure that walnut trees have a robust structure and optimal fruit production. This guide provides a detailed explanation of how to prune and train young walnut trees, offering essential knowledge for successful walnut cultivation.

Growing walnut trees is not just about planting; it involves a conscious process of care and management. Pruning and training young walnut trees are critical stages of this process, requiring careful planning and execution. The aim of this guide is to outline the necessary steps and techniques to support the healthy and productive growth of young walnut trees.

General Information:

• During the establishment of a walnut orchard (first year of planting), the top of the sapling is cut back from the graft union by 4-6 buds.
• Following this cutting, the trunk of the sapling is coated with water-based white latex paint or special tree protectants to protect it from sunlight.
• In walnut cultivation, either central leader or modified central leader training systems are applied to the saplings.

Central Leader System:

• In this system, the canopy branches of the trees become more robust.
• Primary lateral branches should be distributed spirally on the trunk with vertical intervals of 60-80 cm.
• The height of the first primary lateral branch from the ground should be 1.5-2.5 meters.
• Secondary branches on the primary branches tend to grow horizontally. Therefore, the height of the secondary branches from the ground should be at least 2.5-3 meters.
• Whether the central leader or modified central leader training system is preferred in the walnut orchard, the branches forming the canopy should be located on the tree as far apart from each other as possible, both vertically and horizontally.
• In the first years, excess branches that disrupt the system should be pruned and removed.
• In regions with intense sunlight, in the first years, a few small branches should be trimmed with notches on the southwest side of the trunk to provide shade.
• These lower branches, which are left uncut for protection and shading purposes, should be completely removed by pruning at the leaf shedding period when the crowns of the trees develop and provide sufficient shade.

Modified Central Leader System:

• In this system, since the branches are distributed in a smaller area, they tend to develop weakly, and therefore, there may be more branch breakages.

Pruning Times:

• Pruning operations are generally carried out in winter months.
• Pruning done after rain reduces the risk of disease.

Things to Consider in Pruning:

• Pruning operations should be done with sharp and clean pruning tools.
• Cut branches should be cleaned and removed from the orchard.
• After pruning, wounds should be sealed with appropriate pruning sealants.

Benefits of Pruning:

• Pruning ensures the healthy and balanced growth of trees.
• It increases fruit yield and quality.
• It strengthens resistance to diseases and pests.
• It facilitates the exposure of trees to sunlight and air.

Additional Recommendations:

• Consider the climate conditions and soil type of your region while performing pruning operations.
• Seeking assistance from a professional agricultural engineer when pruning your saplings would be beneficial.

Additional Resources

For a more detailed look at pruning and training young walnut trees, you can consult these resources:

• UC Cooperative Extension: Training Young Walnut Trees: Minimum Pruning vs. No Pruning Compared
• West Coast Nut: Training Young Walnut Trees