Fall cold | How do fruit trees prevent the hazards of cold spring?
By: Date: 2021-03-10 Categories: foodtechnology Tags: ,
   spring is coming, although the temperature has risen significantly, but with the end of the dormant period of fruit trees, the ability to resist low temperature and freezing damage is significantly weakened. Many fruit trees that are in the bud sprouting, flowering, and young fruit stage are frost-damaged. Therefore, we must take precautions and countermeasures.

   Pay attention to weather changes and raise awareness of prevention:

   try to set up their own actual observation records of temperature and ground temperature in the garden, and keep an eye on weather changes and weather forecasts, especially every year before the fruit trees germinate, in understanding the local weather On the basis of the long-term weather forecast of the department, pay attention to the short-term weather forecast of the flowering period at any time, predict the time and intensity of frost, and take emergency preventive measures as soon as possible.

   Create a microclimate environment that is conducive to the growth of fruit trees

   One is to choose a south or southeast slope that is leeward to the sun, and avoid building gardens in low-lying or closed valleys. The second is to build a protective forest belt in the main wind direction of the orchard. The protective forest can not only effectively prevent wind, but also increase the ground temperature and prevent frost in early spring.

  defense measures

  1. Watering:When there is a forecast of strong wind and temperature drop, water the whole garden with cold water, which can effectively prevent the cold wave from attacking and reduce ground radiation; replenish water in the tree and increase air Humidity, increase the dew point temperature, effectively reduce the degree of frost damage. And it can delay the flowering period of fruit trees by 3-4 days, which is beneficial to avoid the frost period.

  2. Tree tray cover:Spread a layer of 10-20 cm thick wheat straw, weeds, straw, leaves and other debris in the tree tray, and water it thoroughly , So that the grass is fully moistened, and then sprinkled with a thin layer of soil, which can not only preserve moisture, but also block the intrusion of cold air, which has a very significant effect on maintaining and increasing the soil temperature and preventing frost damage.

  3. Tree protection:Brush the trunk and main branches with whitening agent in early spring, which can delay the phenological period, and can kill insects and prevent freezing. Straw wraps the trunk, soils to cover the root neck, and shade nets to cover the crown to prevent the fruit tree from freezing, especially the protection of young trees.

  4. Smoke:According to the experience of freezing damage to fruit trees over the years, pay attention to the weather forecast before and after the fruit trees bloom, especially at night, when the temperature drops to the fruit trees. Smoke begins when the critical temperature is frozen. Generally, firewood with more smoke and a little damp is used as raw material, such as wheat straw, residual branches and leaves, sawdust, etc., which are alternately piled up and ignited for smoking. In order to improve the effect of anti-frost, you can put more firewood in the upwind direction and less firewood in the downwind direction. Generally, an average of 4-5 haystacks are placed in an orchard per acre.

  5. Spraying growth regulators:such as cyanidin, potassium naphthaleneacetate, etc., can prolong the dormancy period, delay germination and flowering, and avoid and reduce freezing damage Cause loss.

  6. Antifreeze spraying before flowering:After the fruit tree germinates to before flowering, spray a drug that can improve the stress resistance of the fruit tree, combined with foliar spraying, can Effectively prevent the occurrence of frost damage.

  7. Frost prevention of facilities:check the greenhouse facilities for the delayed cultivation of grapes, pears, and citrus in the greenhouse, and timely repair the damaged scaffolding and mulching, strengthening and binding The large shed can prevent freezing due to damage of the film or being blown away by the wind. When the temperature in the shed is too low, manual heating should be used.

  Remedies after freezing

  1. Moderate pruning:According to the different degrees of freezing damage to the fruit trees, pruning should be done in a timely manner. The pruning time should be carried out after the temperature has risen steadily, generally from the end of February to the end of March. The pruning of severely frosted trees should be done sooner rather than later. According to different degrees of freezing, the amount of pruning and objects can be flexibly controlled.

  2. Prevention and control of pests and diseases:Trees are prone to pests and diseases after freezing. Dead branches and frostbitten branches must be removed in time to prevent pests and diseases to keep the tree healthy.

  3. Restore the root system:In addition to the aboveground part of fruit trees, the surface root system will inevitably be frozen and die. For this reason, it is necessary to water the roots or inject some nutrients that stimulate the development of the root system.

  4. Artificial pollination:Generally, the center flower blooms early, so it is vulnerable to late frost, while the side flower and axillary flower buds are lightly frozen, as long as 10%The stigma of the ovary is not frozen, and the amount of fruit set after artificial pollination is enough for high yield. Artificially pollinated pollen can be bought from the market, because the collected flower pollen has strong vitality. It can be stored for 1 year at -1℃ and 10 years at -10℃; it can also be collected from normal flowers. After drying, cleaning, and collecting, manual point instruction is carried out. Usually, one fruit can sit on one stigma, and as many stigmas are needed as many fruits are needed.

   5. Reasonable fruit retention:Frozen fruit trees generally harm the lower part of the tree and light the upper part. Pay attention to the reasonable retention of the fruit and evenly retain the fruit. Spray more before bagging Anti-mycin and other fungicides to prevent the occurrence of bagged fruit black spot. In addition, use locally-applicable high-quality fruit bags and perform careful operations to prevent the fruit from being knocked off.

  Innovative cultivation mode

   With the frequent damage of late frost, some trees with higher output value and suitable for facility cultivation, such as cherry, peach, plum, apricot, grape, etc., should be added. The scale of large-scale facility cultivation can effectively avoid the harm of cold spring while increasing the output value.