1. Miscellaneous orchard: When the garden was built, the tree species and varieties were not reasonably divided and arranged. From the group structure of orchard, not only the varieties are planted irregularly, but also different fruit trees such as apples, pears and peaches are mixed together, which makes the orchard look very messy. This not only affects the neatness and beauty of orchards, but also affects the standardization and professional management of fruit trees. In particular, some pests and diseases are easy to be infected one after another, which not only increases the difficulty of prevention and control, but also aggravates the pollution of orchards due to the large use of pesticides. The root and leaf exudates of some fruit trees also directly endanger the growth and development of other fruit trees. Some fruit trees are prone to direct pollen sensation, which makes the shape and taste of fruits undergo some unstable strange changes. Although some orchards have a single tree species, there are too many varieties, and some still have many inferior varieties, which leads to pollination confusion and affects the normal fruit shape of the main varieties.

Second, uncultivated orchards: Some orchards almost adopt afforestation-style laissez-faire management after planting, not only the crown can not be trimmed, but even weeds are not removed. The whole orchard, regardless of trees and grass, is full of diseases and pests, and it is deserted all the year round. From the growth and development of fruit trees alone, although fertilizer and water may not be sufficient, branches often grow vigorously because of good soil fertility and few fruit trees. From the structure and shape of the crown, the lower branches are overlapping in rotation, and the upper branchlets are erect. Although the crown volume is not too large, the ventilation and light transmission conditions in the crown chamber are poor because of the dense intersection of branches and the closure of the periphery. Judging from the results, the fruits are few or only on the peripheral surface, and they are small in size, with many diseases and insect pests, poor in quality and basically have no economic benefits.

3. Closed orchard: When the garden was built, the planting density was too high, and the plant spacing was too small, which did not adjust with the expansion of the crown. When the branches are not pulled, they grow upright and it is difficult to bear fruit, but when they are pulled, a large number of branches and leaves of adjacent trees overlap. The whole orchard has formed a closed group, and the ventilation and light transmission conditions are extremely poor, so it is difficult to carry out all kinds of management operations normally. It can be said that only the row spacing of plants is determined, but the row spacing between plants is not managed. Therefore, orchards are often full of pests and diseases, and the quality of branches is poor. Even a small amount of fruit in the crown is mostly in the upper periphery, so it is difficult to meet the quality requirements of commercial fruits. In 1996, we found an eight-year-old apple orchard in Jishan, Shanxi Province, with a row spacing of 1.5m× 2.m.. Because the branches between the rows can't pass, management operations such as weeding, spraying, pruning and harvesting can only rely on people crawling on the ground. Goods can only be placed on the iron sheet when transported, and then tied with a rope to climb down and pull away. It's like doing primitive labor in a primeval forest.

4. Yellowing Orchard: The leaves of normal fruit trees should be pure green, but the leaves of some fruit trees in orchards are very abnormal, and they begin to lose their green and yellow in spring and summer every year, and they will not return to their original green until autumn. This kind of leaves can't carry out normal photosynthesis, thus losing the ability to synthesize organic nutrients. In the short term, it will affect the growth and fruit of the tree, and in the long term, it will weaken the root system, making the tree irreversibly weak and eventually dying. The main reason for this phenomenon is the lack of some effective nutrient elements in the soil, which first caused element deficiency disease in the leaves.

5. Aging orchards; Most of the trees are more than 2 years old. Because the trees are not refreshed and rejuvenated in time, the big and small branches are aging as a whole, accompanied by the phenomena of weakness, drooping and dying. The fruiting branches are seriously over-aged, mostly over 7-8 years old, and it is easy to form weak and short fruit branches. There are many flowers, low fruit setting rate, small leaves and many diseases and insect pests. The yield is low, the quality is poor, and the ability of trees to resist natural disasters is weak. Except for a few long branches, the annual growth of general branches is less than 2 cm. Due to the long-term deterioration of light in the canopy, the branches and buds are weak, and the middle and lower parts of the big branches are bare, resulting in obvious outward movement. This orchard is mainly caused by the failure of pruning technology. As long as there are good latent buds in the trees, the trees can be updated and pruned as soon as possible on the basis of strengthening the management of soil, fertilizer and water, which can restore the tree potential and yield quickly.

sixth, weaken the orchard: the tree is not old, the growth is very weak, and it will decline before it is old, which is also called "small old seedlings" and "small old trees". The basic characteristics of the tree are thin branches, thin buds, small leaves, low nutrition level and minimal annual growth, which are prone to pests and natural disasters. "Little old seedlings" generally refer to young trees under 4 years old that have not yet begun to bear fruit. Their branches are thin and short like mice's tails, and they are very thin. The most serious thing is to live or die after planting, showing a state of stuffy bud and suspended animation. There are three reasons. First, the quality of seedlings is poor, for example, the roots are less damaged, the branches and buds are not full, or they are seriously frozen and air-dried during transportation, and some rootstocks are not suitable, so the roots recover slowly after planting and the seedling period is too long. Second, the planting environment is poor, such as poor soil, lack of fertilizer and water, poor soil viscosity and air permeability, or planted in "tuyere", "hail road" and "frost trough". Third, improper planting techniques, such as root system death due to lack of oxygen when planting too deep, cortex rot at root neck, too close and too high intercropping crops, and serious competition for fertilizer, water and space with fruit trees.

"Small old trees" refer to large and young trees whose growth vigor is extremely weak due to excessive early fruits, which make their nutrients suffer serious losses year after year under the condition of lack of fertilizer and water. Most trees are 5-1 years old. Apart from the above characteristics, the branch analogy is unreasonable. There are too few medium and long branches, too many short branches and leafy branches, too few long leafy branches and too many flowering branches, especially more flowering branches. Trees have strong flower-forming ability, but poor fruit-bearing ability, so they tend to spend more and have less fruits, small fruits, light taste and low yield and quality. This is because the limited storage nutrients in the tree are almost completely exhausted during flowering and flowering, and the nutrients synthesized by the leaves in that year can not meet the needs of normal fruit. There are two main reasons for the "small old trees". First, the soil, fertilizer and water conditions are poor, and the nutrients in the trees are seriously insufficient. Second, pruning only does not cut or retract the branches, and the amount of flowering and fruiting far exceeds the capacity of the tree.

The essence of weakening fruit trees is that long-term nutrition loss is serious, often accompanied by extremely weak roots, so they are often not sensitive to fertilizer and pruning. We can't be impatient when reforming, we can only start with restoring the root system first, and then gradually rejuvenate the aboveground trees.

Seven, the orchard grows in vain: It is certainly not good that the branches of fruit trees are weak and not long, but it is also bad to grow in vain. Contrary to the "small old tree", the overgrown tree belongs to the other extreme type. The crown is erect and crazy, with few short branches and many long branches; There are fewer flowers and more long leaves. Most branches are always long in the whole growth period, and the shoots are short in spring and summer and long in autumn, and they will not stop until the leaves fall, and they will not form terminal buds. Sometimes the leaves are too late to fall off, and the tree still hangs on the branches after dormancy. Although the Changwang branch is very long, it is not stout, with straight shape, long internodes, thin buds, insufficient tissue and many hairs on the upper part, and most of them have not formed terminal buds; Although the leaves are large, they are thin and soft, light in color and poor in quality, and they are expendable shading leaves. There are also some short and medium branches in the lower part of the crown and the inner chamber, but they are thin due to lack of light, and the leaves are small and sometimes grow again in autumn, with weak tissue and little nutrition, which makes it difficult to form flower buds. In a word, the overgrowth of the overgrowth tree consumes a lot of tree nutrients, which makes the branches and buds lack the material basis for flowering and fruiting, which is very unfavorable to production. Generally, this kind of orchard has good soil, fertilizer and water conditions, which are mostly caused by improper management. First, improper water management, when watering too much in spring and summer, the spring shoots keep growing, and the boundary between spring and autumn shoots is not obvious; When there is too much moisture in autumn, the autumn shoots are always long, even without capping, and the leaves are too late to fall off. Second, improper fertilization, just watering without fertilization, replacing fertilizer with water, or too much nitrogen fertilizer, too little phosphorus, potassium fertilizer and organic fertilizer, the new shoot tissue is not full and immature, and it is easy to dry in winter and spring. Third, improper pruning, when cutting too much and too heavy, stimulates the tree to grow vigorously. When the soil is good and fertile, the terminal buds of the original medium and short branches can germinate again and grow shoots, with larger and thicker leaves and thicker branches. In the case of lack of fertilizer and water, the leaves of the long branches are large and thin, light in color and thin, and the short branches in the crown are often weak and weak, and the leaves fall early. Therefore, the soil, fertilizer and water conditions in the Tuchang orchard are generally good, and the root system is also strong. During the transformation, it is necessary to focus on controlling the water and nitrogen fertilizer in the later growth stage and applying more phosphorus, potassium fertilizer and organic fertilizer. In pruning, in winter, the main method is to pull branches together with thinning branches to reduce short cuts, and the long branches should be controlled in summer and reformed as soon as possible.

8. Orchards with flowers but no fruit: In some orchards, fruit trees only blossom without fruit, or bear little fruit, which is called flowers without fruit or flowers without fruit. There are two reasons for this. One is that the pollination conditions are not good, and the fruit does not form normally, which is mainly manifested by serious flower dropping and extremely low fruit setting rate. For example, when the garden is built, there is a lack of pollination trees, or the pollination trees do not meet with the main varieties in flowering period, and the pollen affinity is poor. Also, because the pollination tree is triploid and sterile, it can't produce pollen for normal fertilization. This is the case with flowers of young trees that are not realized. The other is that the nutrition level of trees is low, and the supply of nutrients can only meet the needs of flower bud differentiation, but can not meet the needs of fruit sitting and development after flowering, so the flower and fruit drop are very serious. The few fruits produced are also small and of poor quality. This happens mostly on weak trees and old trees.

9. Orchards in different years: The years of fruit trees are also called alternate years, which refers to the phenomenon that there are many fruits in one year and few or even few fruits in one year. The year with more results is called the big year, and the year with less results is called the small year. For an orchard, when it is light, only a few trees occur locally, and when it is heavy, the output of the whole orchard is unstable year after year. Such an orchard is called a variable production garden. The mechanism of bearing fruit in big and small years is that the excessive bearing fruit in big years exhausts the stored nutrients of trees for many years, interferes with the process of flower bud differentiation, and sharply reduces the flowering and bearing fruit in next year, thus forming small years. In small years, because there are few fruits, nutrients are relatively concentrated in flower bud differentiation, so a large number of flower buds are formed, which leads to overloaded fruits in the next year, thus leading to a big year. Therefore, the essence of the phenomenon of bearing fruit in big and small years is the imbalance between growth and bearing fruit, and the fundamental reason is the imbalance between nutrient distribution and utilization, which leads to the long-term out-of-control of tree development physiology, thus forming a vicious circle. The occurrence of big and small years is often affected by variety characteristics, fertilizer and water conditions and pruning technology level. Generally, the varieties with high fruit-setting rate are more serious in the case of insufficient fertilizer and water and extensive pruning of branches, and vice versa.

1. Continuous cropping orchard: The orchard where the old trees are cut down and the same kind of fruit trees are replanted in the same field, or the same kind of fruit trees are densely interplanted between the old trees is called continuous cropping orchard. Repeated cropping fruit trees are often prone to growth weakness, decline in yield and quality, and even sudden death after several years of growth, which is called replanting disease. This disease can be divided into two categories: physiological and infectious. There are differences and connections between them, and the pathological process is similar, including three stages: physiological, tissue and morphological. The law of its occurrence is that most of them first cause physiological diseases, and the tree body is weak, resulting in reduced resistance, and then infected with bacteria and infectious diseases occur. According to the research, its pathogenesis is that the amygdalin in the old roots and fallen seeds of the previous crop of fruit trees is decomposed by microorganisms in the soil and turned into toxic substances such as acids and aldehydes, which browns the xylem and phloem of the new roots of the following crop of young trees, affecting their water and nutrient transport, and leading to gumming of the aboveground branches. Then weaken the tree vigor and reduce the disease resistance of the tree, and then cause infectious diseases such as canker, neck rot and crown rot. Finally, the leaves turn green, the new shoots become shorter, the amount of fibrous roots and flowering decreases, and the yield decreases. In severe cases, the tree body dies. Another study has proved that autumn pruning and early winter pruning in continuous cropping orchard are easy to aggravate the death of fruit trees in subsequent cropping.