First, apply more organic fertilizer, improve fertilizer and improve soil

    Organic fertilizer contains not only a variety of nutrients required for the growth of pear, and can improve soil structure, increasing nutrient buffering capacity of the soil, to increase the water retention capacity of the soil, to improve soil aeration, reduce root growth and soil resistance, Conducive to the growth and development of pear trees.

    Second, the application of nitrogen fertilizer

    Nitrogen is one of the nutrients required for pear trees. Nitrogen fertilizer absorbs about 0.4 to 0.6 kilograms of nitrogen per 100 kilograms of fruit produced . The use of nitrogen fertilizer on the pear tree growth and development have great impact. Appropriate application of nitrogen fertilizer within a certain range has the effect of increasing the number of branches and leaves of pear trees, enhancing tree potential and increasing yield. However, if an excess of nitrogen fertilizer, it will cause excessive growth shoot, fruit not only causes malnutrition, the lack of calcium-induced physiological diseases occur.

    Among the three elements of NPK, saplings of pear trees require more nitrogen, followed by potassium, and less phosphorus is absorbed, which is about 1/5 of the amount of nitrogen . After the results, the proportion of nitrogen and potassium absorbed by pear trees was similar to that of saplings, but the absorption of phosphorus increased, about 1/3 of the amount of nitrogen . There should be a difference in fertilization. Generally, in the period of saplings, according to the size of the tree, the application rate of nitrogen fertilizer is 5 to 10 kilograms per year of nitrogen fertilizer , and gradually increases to 15 to 20 kilograms after entering the fruiting period. The variety can be increased to 25 kg.

    The absorption of nitrogen by pear trees was the most in the growth period of new shoots and young fruit, followed by the second expansion period of fruits, and the absorption of fruits was relatively less after harvesting. Therefore, the application of nitrogen fertilizer mainly has three periods. The first fertilization period is to apply a certain amount of nitrogen fertilizer before flowering, which can increase the fruit setting rate, promote the growth of branches and leaves, help to improve the ratio of leaf to fruit, maintain the balance of vegetative growth and reproductive growth. In particular, for the saplings and trees with weaker trees, the application of nitrogen fertilizer can promote the growth of branches and leaves and enhance the tree potential; the general application rate is about 1/5 of the annual nitrogen fertilizer application rate . But for Tree more prosperous fruit trees in general should not be in this period nitrogen fertilizer to prevent excessive vegetative growth pear-wang, affecting fruiting. The second fertilization period is after the growth period of the new shoots, before the second expansion period of the fruit, the appropriate application of nitrogen fertilizer and the application of phosphorus and potassium fertilizers will help to improve the yield and improve the quality; but do not catch up too early to prevent the foliage The vegetative growth is too strong, affecting the sugar content and quality of the pear fruit; the amount of fertilizer applied in this period is about 1/5 of the annual nitrogen fertilizer application rate . The third fertilization period is timely preparation of the pear fruit before harvesting, which can prepare for the germination and flowering results of the spring of the next year ; generally the application rate in this period is about 1/5 of the annual nitrogen fertilizer application . For pear trees with weaker trees and more results, if the base fertilizer cannot be applied in time after harvesting, a certain amount of nitrogen fertilizer can be appropriately applied and phosphorus and potassium fertilizers should be applied to restore the tree potential and alleviate the nutrient deficit of the tree. Prepare for the growth and development of pear trees in the coming year.

    Third, the appropriate amount of phosphorus and potassium fertilizer

    Phosphorus potassium is also a nutrient element that needs a large amount of pear trees. For every 100 kilograms of fruit produced, it is necessary to absorb 0.1 to 0.25 kilograms of phosphorus pentoxide and 0.4 to 0.6 kilograms of potassium oxide. Tests on the resulting pear trees showed that the increase in the application of phosphorus and potassium fertilizers was 50% to 85% compared to the single application of nitrogen fertilizers . The application of phosphorus and potassium fertilizer can not only increase the yield of pear trees, but also promote the growth and development of roots, increase the photosynthesis products in leaves, and transport them to stems, roots and fruits. At the same time, phosphate fertilizer has a very significant rooting effect, and the phosphate fertilizer is moderately deep. Shike promotes the deep extension of roots to the soil, which can significantly improve the drought resistance of fruit trees and reduce the occurrence of diseases.

    Pear trees in the soil containing high levels of available phosphorus and potassium, the application of phosphorus, potassium fertilizer, often no fertilizer effect, only pay attention to the combination of nitrogen fertilizer and phosphorus, potassium fertilizer can achieve better results.

    4. Rational application of trace element fertilizers such as boron, zinc and iron   

    Application of boron fertilizer can significantly reduce the occurrence of shrinkage of pear trees, increase the fruit setting rate, and reduce the formation of cork areas in the pulp. For pear trees with potential boron deficiency and mild boron deficiency, a borax aqueous solution with a concentration of 0.3% to 0.4% can be sprayed at the flowering stage . Serious soil boron deficiency may be applied to soil before the germinating fruit per 100 to 250 grams of borax, 3 to 5 years up period, as in the flowering stage and then spraying an aqueous solution of a borate concentration of 0.3% to 0.4%, the effect is better.

    The application of zinc fertilizer has a significant effect on leaf spot and lobular disease of pear trees. The recovery rate of diseased branches is over 90% , which can increase the fruit setting rate of pear trees, increase the yield of pear fruit, and increase the nitrogen, phosphorus and calcium in leaves. and other content level. The more effective spraying method is to spray the mixture of 0.2% zinc sulfate and 0.3% to 0.5% urea in time after the onset , or spray it 3 weeks after the fall of the pear tree in spring , or use 6% before germination . Spraying 8% zinc sulphate solution can play a preventive role. Less effective soil application zinc sulfate, and Zn chelating effect of administering state better, but the high cost, are generally more economical and effective control of the main still spraying. A large amount of organic fertilizer can play a role in reducing zinc deficiency to a certain extent.

    For the treatment of pear trees, the iron deficiency and chlorosis are corrected. At present, the best methods are commonly used: soil application, and the use of “local iron-rich method”, that is, ferrous sulfate and cake fertilizer (bean cake, peanut cake, cottonseed cake) And the ammonium sulfate is mixed in a weight ratio of 1 : 4 : 1 , and the base fertilizer is concentrated into the soil layer with more fine roots before the germination of the fruit tree. According to the size of the fruit tree and the degree of yellowing, the application amount of each fruit tree is controlled at 3 ~ 10 kg. Foliar spraying direct effect of ferrous sulfate generally poor, with the application of fulvic acid iron spraying a mixture of urea treatment yellowing better, but of short duration; also be applied ferrous sulfate 0.3%, urea 0.5 %, in fruit growing season spraying every week. For local conditions, may also be used strong trunk injection machine for injecting ferrous sulphate wood, although the effect is better, the administration amount is small, typically only about 1% of soil application, this method is only suitable for adult Fruit trees, the dose range of injection is narrow, and improper application can easily affect the normal growth of pear trees.

    5. Fertilization time and method of pear tree

    The fertilization of pear trees should be based on base fertilizer. The best base fertilizer application time is autumn, and the early maturing varieties are carried out after fruit harvesting; the middle and late maturing varieties can be carried out before fruit harvesting. The benefits of Qiu Shi are:

    1. Based on observations of root growth pattern that, pear root for 1 year, twice the growth peak period, once in the spring from March to May, once in 9 to 11 months. The base fertilizer is applied in the early autumn from August to September after harvesting , just in time to meet the peak of autumn root growth. Before the freezing, the roots have a growth period of 2 to 3 months, which can heal the wound early and promote a large number of new roots. .

    2. These new roots after autumn absorption can promote the absorption of autumn roots and photosynthesis of autumn leaves, increase the storage nutrition level, improve the quality of flower buds and the fullness of shoot buds, thus improving the cold resistance, and the effect is excellent.

    3. The most important thing is that the roots of the autumn are earlier than the roots of the spring, the early absorption of fertilizer, and the promotion of the spring growth peak of the roots, which is very beneficial to the growth of sprouts, leaves, flowers, fruit set and young fruit. Especially for the development of early leaves and photosynthesis of middle and short branches, the effect is more obvious.

    4. The base fertilizer is applied in autumn and winter. After the winter and spring decomposing, the fertilizer efficiency is best in the most stressful period of spring nutrient (the critical period of nutrition from April to May ). If winter application or spring application, the fertilizer is too late to be decomposed, buried in the soil, and the spring needs to be strong when it is not possible. After the rainy season, it can be decomposed and utilized, which in turn causes the autumn shoots to grow. The autumn shoots are prosperous and compete for a large amount of fertilizer. On the contrary, the medium and short branches are insufficient in nutrients, the flowers are small, the storage level is low, they are not full, and they are susceptible to freezing damage. Therefore, the dense planting garden must adhere to the base fertilizer and apply a small amount of fertilizer in the new year.

    The application period of top dressing has certain differences due to different tree potentials, and is generally carried out before germination, flowering, and fruit expansion.

    1. bud before fat   About 10 days before the germination , the roots began to move. Successive flower buds, leaf buds, new shoots, leaf growth, flowering, and fruit set require a large amount of protein. In this period, topdressing should be based on nitrogen fertilizer. Recover the amount of fertilizer to be bigger, after fertilizer irrigation.

    2. After falling flowers   The new shoots are slowed down from vigorous growth to stop growing, and the flower buds are prepared for nutrient preparation before differentiation. It is also the transition period between new and old nutrient transfer. If the fertilizer is insufficient or not timely, it will easily cause physiological fruit drop and affect flower bud differentiation. This period should be based on the application of three elements or multi-element compound fertilizer.

    3. Fruit swelling fertilizer   From July to August , the pear fruit is rapidly expanding. In this period, potassium fertilizer should be used together with phosphorus and nitrogen fertilizer to increase the yield and quality of fruit, and promote flower bud differentiation.

    The specific fertilization method depends on the size of the tree. When the tree is small, the fertilization is generally carried out. The position of the fertilization is preferably 0.5 to 2.5 m outside the canopy, and the groove is 20 to 40 cm wide and 20 to 30 cm deep . The fertilizer is mixed with the soil moderately and then applied to the ditch, and the ditch is filled in. Adult pear trees are best fertilized in the whole garden, combined with cultivating to turn the fertilizer into the soil. Since the roots of pear trees are mainly concentrated in the range of 20 to 60 cm in the soil layer , and the growth of roots is obviously fattening, it is best to apply deep soil layers of 20 to 40 cm deep for organic fertilizers and phosphorus and potassium fertilizers to improve root depth and breadth of distribution, absorption enhancing pear, improve the drought resistance of the solid and the tree.

    In addition, root dressing can also be carried out. The top dressing is also called foliar spray fertilizer, that is, the chemical fertilizer is formulated into an appropriate concentration, sprayed on the leaves, branches, and table tops with a sprayer, directly absorbed and utilized through the lenticels, pores, and cortex, eliminating the need to absorb through the roots. The advantage of this method is the upward transport of the distribution process:

    1. Save labor and fertilizer, and it will be very effective   The urea can be absorbed in a few hours after spraying, and it can absorb 80% in 24 hours . After 2 to 3 days, the leaves turn green. In production, the “bright leaf fertilizer” effect is excellent in May after falling flowers . At the peak of a peak lack of fat, it is the best measure for first aid.

    2. Improve fertilizer utilization   Spraying fertilizer can prevent the loss of fertilizer due to soil fertilization by soil, or the disturbance of soil physical and chemical properties, which can greatly improve the utilization rate of fertilizer.

    3. Overcome nutrient competition   Spray fertilizer can overcome the nutrient competition in the center distribution caused by the various growth peaks. The medium and short branch leaves can be directly absorbed and utilized to form more flower buds, especially for the young and old trees .

    4. Increase local nutrient accumulation   Spraying fertilizer combined with summer flowering measures such as pulling branches and ring stripping increases the local nutrient accumulation of the treated branches, and promotes flower yield increase. In the pear orchard lacking trace elements, the effect of spraying fertilizer is the most appropriate.