1 Harm and treatment of poor soil
1. 1 Poor soil and insufficient nutrients are the biggest obstacles to the quality improvement and efficiency improvement of Hua Niu Apple. For a long time, the application amount of soil organic fertilizer was seriously insufficient, which led to soil hardening, nutrient deficiency and decreased water and fertilizer conservation ability in Tianshui orchard. The average organic matter in Tianshui orchard is only 0.905%, and the available nitrogen, available phosphorus and available potassium are 32.40mg/kg, 4.45mg/kg and 136.40mg/kg respectively. Except available potassium, the rest are at a low level, which is 65438 0.20% ~ 2% compared with the national production standard of pollution-free fruits. Poor soil makes the growth and development of fruit trees in a state of malnutrition for a long time, which leads to poor tree potential, poor flower bud quality, decreased fruit setting rate, low and unstable yield, decreased fruit quality and weakened fruit storage performance. This has directly affected the development of the dominant industry of Huaniu Apple, and has become a prominent problem of the dominant industry of Huaniu Apple in Tianshui, which should be highly valued by the government and people in the industry.
1.2 Treatment of poor soil
1.2. 1 soil fertility. According to the actual situation of Tianshui orchard, soil fertilization should be based on reducing fertile soil on the horizontal platform and building high-yield ditches, and efforts should be made to thoroughly solve the bottleneck problems in the production of Hua Niu Apple by applying sufficient organic fertilizer, reasonably topdressing, spraying micro-fertilizers on leaves, planting grass in orchard and storing fertilizer and water in caves.
1.2.2 Re-apply organic fertilizer. Some low-yield orchards in Tianshui do not apply organic fertilizer or only apply a small amount of chemical fertilizer. According to the requirements of pollution-free fruit production, it is necessary to increase the amount of organic fertilizer and reduce the amount of chemical fertilizer. The annual amount of organic fertilizer is 3000～4000kg. Organic fertilizer is accumulated and decomposed in June-July, and applied in annular ditch or radial ditch in September-65438+1October, with fertilization depth of 40-50 cm, and then raked flat.
1.2.3 minutes to store fertilizer and water. Dig fertilization holes 50cm inward from the crown projection, and 2 ~ 4 holes can be dug according to the age of the tree. The diameter of the fertilization hole is 30 ~ 40 ~ 50 cm and the depth is 40 ~ 50 cm. A straw stalk is placed in each hole, and the size of the straw stalk is15 ~ 25cm, and the length is 30 ~ 35cm. Before placing the straw, completely soak it in water, and put it in fertilization holes. When the soil is half buried, apply 100g phosphate fertilizer in each hole, and continue to bury the soil. When it is 2 ~ 3 cm away from the ground, apply 50 ~ 100 g urea in each hole, then water 5kg, and finally cover it with plastic film. The film-covered part is lower than the ground, and the opening in the middle is convenient for rainwater collection and leakage. In the future, topdressing and irrigation can be applied from plastic film holes, and the fertilization holes can be changed once every two years.
1.2.4 The orchard is covered with grass. White clover has shallow roots and less competition with fruit trees for fertilizer and water. It has the functions of enriching soil, inhibiting weeds, storing water and preserving moisture, reducing the labor intensity of weeding and reducing the production cost. Therefore, we advocate planting white clover between rows of apple trees. The method is to plant trees in rows of 1.50m and rows of 2.50m, and sow grass in spring (March-April) with 0.50kg of grass seeds per mu. Seedlings should pay attention to weeding and assist the growth of white clover. Lawn can be formed in 65,438+0 years, covering the ground.
1.2.5 Rational topdressing. Fertilizer is mainly topdressing. 1 topdressing before germination (early March), fertilizer is needed to ensure flowering and fruit setting, mainly nitrogen and potassium fertilizer. The second topdressing is to promote flowering and fruit expansion before the physiological differentiation of flower buds (late June), mainly phosphorus and potassium fertilizers. According to the requirement of producing 100 kg of fruit, 0.80 kg of nitrogen, 0.50 kg of phosphorus, 0.70 kg of potassium, 2,000 kg of flowers, 2,000 kg of cattle and 2,000 kg of apples are required, and each time nitrogen 16 kg, phosphorus 10 kg, potassium 14 kg are required.
1.2.6 foliar fertilizer. Foliage fertilizer is mainly used to supplement fertilizers with high nutritional value, which are difficult to be absorbed by fruit tree roots or quickly supplemented, such as trace elements such as calcium, magnesium, boron, zinc, iron and manganese. It can be used many times after the apple blooms and sets fruit, at the young fruit stage and at the fruit swelling and coloring stage. The main foliar fertilizers are potassium dihydrogen phosphate (0.30%), calcium chloride (1% ~ 2%) and magnesium sulfate (magnesium sulfate).
2 the harm of drought and drought resistance and moisture conservation
2. 1 The drought tends to increase, threatening the cultivation and growth of the dominant industries of Hua Niu and Apple.
More than 95% orchards in the main producing areas of flower cattle and apples in Tianshui city have no irrigation conditions. The precipitation in winter and spring (12 ~ May) is 1 17.80mm, accounting for only 2 1.90% of the whole year. The precipitation above 1 field 10mm in spring changes greatly. The dormancy period (from mid-July to mid-August) is also the fruit expansion period of Huaniu Apple. The precipitation is generally 100 ~ 120 mm, and the drought year is less than 10mm. The total rainfall in normal years is not small, but the rainfall is too concentrated and less in winter, spring and early summer, which often leads to continuous drought in winter, spring and early summer and cannot meet the water demand of fruit trees. The growth of new shoots is limited and the nutritional area is reduced. When there is serious water shortage, trees will shed their leaves early, which will not only affect the fruit yield and quality of the year, but also affect the accumulation of flower buds and storage nutrients in trees.
2.2 Drought resistance and moisture conservation
Drought is another outstanding problem in the production of flowers, cows and apples in Tianshui. In the past ten years, the drought has intensified. In addition to applying organic fertilizer, covering grass, planting grass and storing fertilizer in caves, we should make full use of runoff water, river water and well water for timely and effective irrigation to alleviate or alleviate drought and promote the normal growth and development of fruit trees.
2.2. 1 The implementation of "changing slopes into ladders", building gardens in fish scale pits and high-yield ditches, collecting runoff water and accumulating soil moisture are the basis of the dry farming technology of Huaniu Apple. Because more than 90% orchards in Tianshui are distributed in arid mountainous areas, most orchards have no irrigation facilities, and the runoff generated by heavy rainfall is lost in vain because of the steep slope. Therefore, when the garden is built, the sloping land should be transformed into an anti-sloping terrace, or fish scale pits should be dug first, and high-yield ditches or pits should be planted to fully collect natural precipitation and runoff water to increase soil moisture.
2.2.2 Improving soil fertility and soil organic matter is an important link to realize water transfer and water conservation with fertilizer. Vigorously promote the application of organic fertilizer, planting grass and covering grass, storing fertilizer water in caves and other orchard fertilization techniques to achieve the purpose of storing water with fertilizer.
2.2.3 Orchards with irrigation conditions should be irrigated scientifically, economically and reasonably. Changing flood irrigation into pipe hole irrigation, micro-irrigation and sprinkler irrigation can generally save water by 50% ~ 60%. According to the growth characteristics and drought characteristics of Tianshui Huaniu Apple, irrigation for three times in the germination stage, fruit expansion stage and freezing stage can alleviate the drought and basically meet the water demand of fruit trees. It is worth pointing out that irrigation during the freezing period can not only avoid the peak of water consumption in the growing period of crops, but also promote the safe overwintering of fruit trees and maintain good soil moisture in the next spring, which is extremely beneficial to the flowering and fruit setting of flowers, cows and apples.
3 Frost damage and late frost damage
3. 1 Freezing injury and late frost occur frequently, which affects the improvement of the yield and quality of Huaniu apple.
Low temperature freezing injury and late frost occur frequently in Tianshui in spring. According to meteorological data, freezing injury and late frost occurred in 25 years out of 36 years, including 17 years in the whole city, once every two years on average. On May 3-4, 2004, freezing injury and frost occurred in a large area in Zhangjiachuan County, which caused all the 3 600hm2 fruit trees in the county to be frozen, and the output of apples, pears, apricots, plums, walnuts and apple trees decreased by 50%-90%, resulting in a direct economic loss of 6,543,800 yuan. In April 2006, the persistent freezing injury and frost from May 438+01to June 5438+04 resulted in the failure of sweet cherries and apricots in Tianshui, and the reduction of apple production by 20%. 7.20% of Yuanshuai apple fruits suffered from "frost ring disease", and 2 1.30% were rough. The fruit shape index of Marshal apple was 1.052, which was 8% ~ 9% lower than that in 2005 when there was no freezing injury. The direct economic loss caused by freezing injury and late frost is more than 500 thousand yuan. It is a long-term task for fruit workers to prevent and reduce the harm of freezing injury and late frost.
3.2 Prevention of freezing injury and frost
3.2. 1 Strengthen fertilizer and water management and enhance the cold resistance of trees. Apply sufficient organic fertilizer, skillfully apply chemical fertilizer, spray micro-fertilizer, and combine fertilization to make full use of natural precipitation and well water. River irrigation can ensure the nutrients and water demand of trees, enhance the vitality of trees and improve the frost resistance.
3.2.2 Reasonable pruning and proper load. Through shaping and pruning, a tree structure with firm skeleton and reasonable branch distribution is established. At the same time, according to the requirements of producing high-quality and high-grade fruits, flowers and fruits should be strictly thinned, so as to achieve reasonable load, maintain vigorous tree growth and enhance cold resistance.
3.2.3 Orchard irrigation and tree spraying. The flowering period of Tianshui Huaniu apple is in the middle and late April, which is also the prone period of low temperature freezing injury and frost. In order to avoid and reduce the harm of freezing injury and late frost, orchard irrigation 1 time at the end of February and the beginning of March on the basis of winter irrigation for fruit trees can reduce soil temperature, increase humidity, delay germination and flowering, and miss the occurrence period of freezing injury and late frost. At the same time, when predicting the occurrence of freezing injury and late frost, spray water on the trees with a sprayer before dark to increase humidity, release heat, increase the temperature of the orchard and reduce the loss of freezing injury and frost.
3.2.4 The suitcase shall be painted white. In late June165438+1October, after the trees shed their leaves, a whitening agent was prepared with 5 kg of quicklime, 2 kg of salt, 0. 10 kg of vegetable oil and 20 kg of water to whiten the trunk and reduce the temperature, temperature difference and freezing damage of the trees.
3.2.5 There is smoke in the orchard. Straw, weeds, leaves, etc. Plants, such as wheat straw, which are evenly distributed in the garden or gathered a lot of smoke in the upper air inlet, are ignited at 2 ~ 3 am before the frost appears, forming a smoke layer on the upper crown, which can not only isolate the frost, but also increase the temperature of the orchard by 1 ~ 1.50℃ to avoid freezing injury.
3.2.6 Spraying prevention. Spraying PBO 20 days100 times in rainy autumn can increase the material accumulation of trees and enrich their tissues. Robust, enhance frost resistance. At the same time, spraying PBO 1 times 100 times before flowering can improve the frost resistance of flower organs, shoots and young leaves.