Macadamia nuts should pay attention to the young trees leaving only one central trunk. If there are two or more upright trunks on a tree, there are many disadvantages: first, there will be competition between trunks, which will stimulate the abnormal growth of trunk nutrients and is not conducive to flowering and fruiting; Secondly, the main branches of different main branches overlap and interfere with each other, which makes it more difficult to cultivate reasonable pruning of main branches; Thirdly, due to the existence of excessive stems, the included angle between stems is small, and it is easy to split when encountering strong wind and high fruit yield, and the fruit bearing area of plants decreases in a certain period, which directly affects the yield. Macadamia nuts have three vertically side-by-side buds in each axil (four in thick-rooted plants). When the branches are cut off, the upper three axillary buds will grow upright, which is more suitable for cultivating into trunk. If the terminal bud is cut off, the lower bud will germinate and germinate, and the deviation angle between the branch and the trunk is large, and the connection with the trunk is not easy to be torn, so it is most suitable as the main branch; If the second bud is cut off, the branches from its lower bud will grow approximately horizontally outward, and the growth potential is slightly weak. According to the bud characteristics of macadamia nuts, plants that do not grow long-distance main branches after planting should be topped or chopped at a height of 70 ~ 80 cm from the ground. After germination, the cuttings are evenly distributed within 20 cm below the cuttings, with staggered directions and moderate angles. Three strong branches with a certain distance are used as main branches for culture, and the rest are thinned. The new trunk is selected from the main branches of three main buds, and the main branches of the trunk are cultivated from the main branches of the middle buds. After short cutting, when the branches are slightly mature, keep the strongest upright branches among the three main buds. In order to cultivate the trunk, all other main buds should be cut off, and the middle branches with smaller angles to the new trunk should also be cut off. Keep the other two medium buds on the same node or the main branches pumped by three medium buds on the next node to cultivate the backbone main branches. For varieties (such as Ownchoice and 695#) with weak apical dominance and many lateral branches, the trunk does not need pruning, and only the selection and retention of main branches are considered for pruning. For varieties with weak apical dominance, the main branches tend to be much longer. If the spacing of lateral branches in each round is too small, less than 40cm, the main branches with small branching angles should be thinned out on the basis of overall consideration. If there are too many branches (more than 3 ~ 4) on the same impeller, choose 3 ~ 4 main branches with large and strong included angle with the trunk, place them evenly on the nodes, and cut off the rest. Pruning macadamia nuts starts from young trees, and it is easy to form a reasonable tree shape through layer culture. If young trees are not pruned, it is difficult to form them until mature trees are formed. Pruning should not be too frequent, 1 year can be done 2 ~ 3 times, young trees should be cut short during the growth period, and thinning should be mainly in winter. Don't prune too much at a time, and the branches and leaves cut at a time should not exceed 1/3 of the crown, so as not to exceed the growth and affect the normal growth. When pruning, attention should also be paid to cutting off dead branches and long branches caused by low parts (below 70cm), side branches extracted from rootstocks, pests and diseases,

2. Pruning techniques for adult trees

Macadamia nut is the fruit of inner cavity, and flowers and fruits are mainly planted on mature branches inside the crown. The main purpose of fruit tree pruning is to enable the upper and lower parts of the crown to extract fruit branches with reasonable and uniform distribution, so as to make full use of space, increase fruit surface and increase yield. Pruning is mainly carried out in winter, followed by pruning in summer. Different branches are pruned in different ways.