Occurrence and Preventive measures of Golden Pear Fruit

Golden pear was introduced into our city in 2000. Through high grafting and changing head, it has developed to 2567 hectares and began to hang fruit in 2001. However, in the production, it is found that the fruit surface of golden pear is easy to form fruit, and the rate of good fruit is 30% to 50%, which seriously affects the economic benefits of fruit farmers. For this reason, we have carried out investigation and analysis, found out the reasons and put forward the corresponding countermeasures.

1. Cause of occurrence

Internal factors: the occurrence of golden pear fruit is closely related to its pericarp structure. The epidermal cells of golden pear fruit not only thicken the outer wall, but also secrete horny to the outside, which makes the cell wall keratinized and forms the stratum corneum outside it. However, the stratum corneum structure of golden pear is not uniformly arranged and dense into layers, but loosely attached to the skin of the fruit. The pericarp characteristic of Golden Pear makes it vulnerable to damage. Once it is affected by the adverse external environment, the cuticular layer will be broken, which will induce the secondary protective tissue-cork layer (fruit clot), in order to further strengthen the protective effect on the fruit. Therefore, the formation of fruit fruit is the result of a physiological protective response caused by the encounter of epidermal cells and stress. Cork tissue produced by cork formation of epidermal cells or division of subepidermal cells.

External factors: the external factors that cause the fruit blossom of golden pear can be summarized as the following, that is, the nutrition of the tree is unbalanced, such as applying too much nitrogen in the middle and later stage of fruit expansion, which makes the fruit rich in protein and amino acids and causes the fruit to expand rapidly. because the epidermis and cuticular layer of the fruit can not keep up with the speed of fruit expansion, cracking results in the formation of pear spots. The orchard did not adopt the cultivation methods such as net frame, and the branches could not be fixed, and the young fruit was milled by the branch sweeping leaves to form the fruit; the orchard was closed, the crown branch was too large, and the ventilation and light transmission was poor; in the young fruit stage, the medication was unreasonable, the spraying times were too many, the varieties were too miscellaneous, the spray head pressure was too high, which caused mechanical damage to the young fruit; the bagging time was too late, and the young fruit was exposed for too long. The poor quality of the fruit bag leads to the damage of the fruit bag not resistant to Rain Water scouring, and the fruit bag is not easy to dry after absorbing moisture. At the same time, the potion and Rain Water are easy to stimulate the fruit surface through the fruit bag to form the fruit bag; the bagging operation is not standard, the fruit bag is not tightly fastened to the young fruit surface or the mouth of the bag is not strictly sealed, the fruit bag is rubbed by the wind, at the same time, Rain Water and the medicine are easy to enter the fruit bag to form the fruit bag.

2. Technical measures to prevent the occurrence of golden pear fruit stalks.

The cultivation method of grid frame can be adopted: standard net frame or simple net frame, such as bamboo pole frame, etc., the height of the frame can be controlled at 1.8m to 2.0m, the branches are bound by hanging branches, the levels between the branches are distinct, the layout is reasonable, and the pears are ventilated and transparent in the garden. At the same time, pears are all under the grid to avoid branch grinding and leaf sweeping.

Strengthen cultivation management: on the basis of re-application of organic fertilizer, formula fertilization is carried out according to the analysis of leaves and soil. According to the actual situation of our city, each production of 100kg fruit requires the application of pure N, P, K 1kg, and appropriate supplement of iron, zinc, boron, calcium and other micro-fertilizers. It is recommended to cover the orchard with grass on a tree plate. Carry out artificial pollination, @ # @ 255 pollination or wall bee pollination to make full fertilization. Carefully thinning flowers and fruits, select young fruits with straight shape, bright color, thick and long stalk, growing on both sides of branches and covered with leaves. In the same inflorescence, one of the 2nd ~ 4th ordinal fruits is generally selected from the base, and the rest are all removed. Under reasonable load, the yield of the full-fruiting tree was controlled at 2500~3000kg per 667m2. The above measures can make the tree grow steadily, coordinate the growth and development of fruit, and enhance the resistance of young fruit to external adverse environment.

Careful pruning: in shaping and pruning, happy shape should be used for reconnected trees, and spindles can also be used for newly planted young trees. Flexible methods such as the combination of winter and summer pruning and thinning, cutting and swinging should be paid attention to in shaping and pruning, and the number of branches per 667 square meters should be controlled at 35 ~ 40, 000 after winter pruning. Pruning should be meticulous, and pay attention to updating the fruiting branch group, leaving strong branches to bear fruit, generally thinning twigs, weak branches, weak flower buds and axillary flower buds, flower branches should account for about 30% of the total branches, and excess flower branches can be broken and pruned to transform them into fruiting branches of the following year.

Scientific use of medicine before bagging: since the young fruit stage is a sensitive period for the occurrence of fruit pear, we should choose pollution-free germicidal insecticides with high efficiency, no irritation to the pericarp or less irritation to the pericarp, such as Dasheng Mashi 45, methyl thiophanate (pure), carbendazim (pure), Xinsheng, polyantimycin, imidacloprid, etc., do not use agents that are irritating to the pericarp, such as copper preparation, Fumei, mancozeb, etc. The type of medicine should not be more than three, and the concentration 'degree should be as small as possible; the degree of atomization should be fine when spraying, and the sprinkler should not be too close to the fruit surface and stay too long; dispensing water should not be used in wells with high hardness and polluted river water; spraying time should be carried out at 9-10:00 or 4: 6 p.m., avoiding dew on the fruit surface and noon in the hot sun. Bagging can be carried out after the solution is dry.

Young fruit bagging technology: ① bagging time: using twice bagging technology, should begin to cover the small wax bag 10-15 days after Xie Hua, 40 days after the first small bag, do not go to the small bag, directly cover the big bag. You can also cover 3-layer paper bags only once, and the bagging task should be completed 15-30 days after Xie Hua. ② bagging types: the reason why bagging can prevent the formation of fruit fruit is to weaken the stimulation intensity of external adversity, so we should attach great importance to the choice of fruit bag quality. It is best to buy regular, brand-name paper bags. The two-time bag is used, the small bag is milky white wax bag, and the large bag is high-quality wood pulp paper double-layer bag. For the one-time bag, you can choose the three-layer bag of outer yellow wood pulp paper, middle double-sided black paper and inner cotton paper, and the inner cotton paper should be smooth and soft to prevent scratching the young fruit. ③ strict bagging operation: the time bag should be bulged, the fruit should be suspended in the bag, and the mouth of the bag should be tightly sealed to prevent strong wind, water, medicine, fruit stalk, hidden pests and so on. ④ spray once before bagging can maintain bagging for 3 days, or make up spraying in case of rain.