How to manage walnut trees after harvesting the fruit? Remember these three key points

During the fruiting period, walnut trees consume a large amount of nutrients from the tree body because of the needs of the fruit. Therefore, after the fruit is harvested, walnut trees must be managed reasonably and effectively. This not only ensures faster recovery of tree vigor, but also plays an important role in preventing the occurrence of pests and diseases.

1. Deep plowing of the soil after harvesting the fruit. Walnut tree roots generally penetrate relatively deep into the soil, and whether the soil has good aeration directly affects root growth. Therefore, after the fruit is harvested, the orchard soil should be deeply plowed. Deep plowing is generally carried out before the fruit trees shed their leaves, to a depth of 25-40 cm. This is also the second growth peak of walnut tree roots. Deep plowing is beneficial to root growth; many damaged roots heal easily and produce new roots, soil nutrients transform quickly, and this is conducive to the accumulation of nutrients in the tree body.

2. Reasonable fertilization. The fertilization period is from early September to late October. Fertilization can mainly use organic fertilizer and biological bacterial fertilizer suitable for walnut tree growth, which can improve the soil, prevent compaction, and promote aeration. At the same time, an appropriate amount of nitrogen, phosphorus, potassium and other medium and trace element fertilizers can be added. For walnut trees bearing fruit for the first time, apply 15 kg of high-quality organic fertilizer, 0.15 kg of biological bacterial fertilizer, and 1 kg of nitrogen-phosphorus-potassium fertilizer per tree, plus 200 g/mu of Ciba boron-zinc trace element fertilizer; for trees in full fruiting stage, apply 25 kg of high-quality organic fertilizer, 0.25 kg of biological bacterial fertilizer, and 2 kg of nitrogen-phosphorus-potassium fertilizer per tree, plus 300 g/mu of Ciba boron-zinc trace element fertilizer. When fertilizing, for 2-4 year old trees bearing fruit for the first time, use the broadcast application method under the tree canopy; for large trees 5 years old and above, dig trenches along the rows and fertilize, mix the fertilizer and soil evenly and then fill it back into the trench, or alternate trenching and broadcast application followed by turning the tree plate every other year. In addition, watering should be coordinated well. Generally, after deep plowing or trench fertilization, irrigate promptly and thoroughly. In dry years, irrigate once more before the soil freezes.

3. Timely and correct pruning. When pruning walnut trees, the appropriate time must be grasped. Generally, pruning during the dormant period is prone to bleeding and weakens tree vigor, and may even cause local branches to die. Therefore, the pruning time is best controlled before leaf fall in autumn or after bud break in spring. Pruning from the Autumn Equinox to Cold Dew is best; pruning at this time helps the wounds heal as early as possible within the same year. If the pruning workload is large, it can also be done in winter 30 days after leaf fall or 25 days before bud break, which can reduce the adverse effects of bleeding on the tree body. In addition, on the basis of grasping the appropriate pruning time, the pruning method must also be appropriate. In the young tree stage, walnut trees have vigorous nutrition, shoots grow rapidly, and the canopy expands year by year. At this time, pruning should focus on developing the trunk, keeping the main branches well, retaining auxiliary branches, and promptly thinning dense branches, water sprouts, and weak slender branches. More fruiting branches should be kept inside the canopy, and pruning is best combined with branch bending. For densely planted trees, branch bending should be the main method and pruning supplementary. This kind of pruning not only ensures that the main branches are evenly distributed and grow evenly, but also makes the canopy levels distinct, open, and not lopsided, ensuring balanced development of tree vigor and gradually cultivating a full-shaped tree with a large fruiting volume.

Liu Chaobin