Common Walnut Tree shape and shaping techniques

  Reasonable tree shape is the skeleton of tree body, the basis of load yield, and the basic condition of high yield, high quality and high efficiency. The purpose of shaping is to create a solid tree skeleton that ensures maximum light interception and high yield of the canopy. Reasonable tree shape should accord with the requirements of early fruit, high quality, high yield, easy management and high benefit. The specific tree shape should be determined according to site conditions, management level, variety characteristics and cultivation methods.

  With the trend of tree height becoming shorter, tree density increasing from low to high, tree shape becoming simple, tree structure of fruit trees has changed greatly. The tree shape with small individual and simple structure replaces all kinds of trees under the condition of large canopy and sparse planting. Its goal is to make full and reasonable use of space, obtain the best population benefit, cultivate reasonable and robust structure, and keep stable tree vigor, so as to make it bear larger yield.

  The heterogeneity of walnut branches and buds is very strong, and it is difficult to form a good tree shape if it is allowed to grow naturally. Especially early-fruiting walnut, because of its strong branching force, early results, easy to send secondary branches, more likely to cause tree chaos. Therefore, in the cultivation and management of walnut, we must pay attention to the young tree shaping work.

  At present, there are two main types of walnut trees in China, namely, the trunk shape represented by the scattered hierarchical shape and the open shape represented by the natural open shape. There are 6~7 main branches, which are divided into 2~3 layers spiral on the central leading trunk, forming a semicircular or homocentric crown. The tree is suitable for growing in better conditions and dry trees. There is no central leading stem in the natural happy shape, and there are usually 2 to 4 main branches. It is characterized by rapid formation, early fruiting, flexible arrangement of backbone branches at all levels, easy shaping and easy to master. Young trees are more upright, gradually open after entering the fruiting period, good ventilation and light transmission, easy to manage. The tree shape is suitable for early-fruiting walnut varieties planted in areas with thin soil layer, poor soil quality and poor fertilizer and water conditions. According to the number of main branches, open shape can be divided into two main branches, three main branches and multi-main branch open shape, among which three main branches open shape is more common; according to the size of the opening angle can be divided into multi-trunk shape, straight body shape and open shape.

  In production practice, the proper shaping methods can be selected according to variety characteristics, planting methods, site conditions, management level, etc. Under normal circumstances, early-fruiting walnut dry weak, should use open shape, late fruiting walnut dry strong, Xuan use trunk shape; sparse planting can be used trunk shape, dense planting can be used open shape; mountain cultivation growth weak, easy to cultivate into open shape, flat and management level under the conditions of higher growth potential, can be cultivated into trunk shape. The general principle of walnut tree shaping is: "visible not dead, invisible not chaotic; because the tree pruning, with the branches for shape."