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Post harvest management of large cherries

Release time:

2019-07-25 17:01

The technical management of sweet cherry trees after fruit harvesting is very important because at this time, the tree body undergoes the process of leaf expansion, shoot extraction, flowering, fruit setting, and fruit growth and development, consuming a large amount of nutrients stored in the tree body. After fruit harvesting, it enters the stage of nutrient accumulation through photosynthesis. Manage the production well during this period. Its technologies include summer pruning, removing dense branches, chemical control, fertilization, disease and pest control, and other main technologies.
1. Reasonable summer cutting and timely control
1.1 After harvesting sweet cherries with sparse branches, those that have grown too dense, thin and weak branches, whiplash branches, and diseased and insect branches should be pruned or cut short to open up the light path, enrich the branches, reduce unnecessary consumption, and facilitate flower bud differentiation and maturation of the branches. Mainly targeting strong and closed trees, it should be carried out from top to bottom. When thinning trees with excessive upper branches, it is not advisable to do so in one step. It should be done in two stages, with 1-2 large branches each time, with an interval of 1 month; The weak and ineffective branches behind the inner chamber should be removed at once; Overdense tips on the back should be removed at once; Retain one extended branch for the flourishing branches that extend, re pick 1-2 branches, and remove all other branches. The intuitive standard for a reasonable amount of branches and leaves is that when the sun shines directly on the tree crown, the ground light shadow coefficient is between 30% -40%.
1.2 Twisting and pinching twigs refers to twisting the vigorous growing branches and competing branches 180 ° during semi lignification, weakening their growth potential, promoting flower bud differentiation, and transforming them into fruiting branches. Those that still grow vigorously after twitching should be gently picked continuously to inhibit growth. Gently pinching the extended shoots can alleviate the tree vigor, but the secondary shoots that occur after pinching should be uniaxial extended.
Picking the heart: Picking the heart is the process of removing the tender part of the tip before the new shoot is lignified, which is called picking the heart. It is the most commonly used method for pruning sweet cherries in summer. Picking the hearts of young trees can promote the germination of more branches and promote the formation of flower buds. Picking the hearts of trees during the initial and full fruit stages can save nutrients, improve fruit setting rate, and improve fruit quality.
Heart removal can be divided into mild heart removal, moderate heart removal, and severe heart removal.
Mild decapitation involves only removing the top 5cm or so, and after decapitation, only 1-2 new shoots can sprout and extend for growth. Control the growth rate between 10-20cm, continuously and lightly pick the seeds, and form fruiting branches.
Moderate picking: The purpose is to promote multiple branches. When the new shoots grow to over 40cm, more than 15cm should be removed, and generally 3-4 branches can germinate.
Severe pinching: When the branch develops to over 40cm, leaving about 15cm for pinching can not only promote branching, but also cause the lower buds to sprout and grow into short branches or leaf clusters, forming a small fruiting branch group. The length of the remaining branches should be determined based on the living space of the branches and the different uses of the branches. As the backbone branch, the remaining branch should be longer and above 40cm.
When the new shoots grow longer and the remaining branches are shorter, and the picking part has become semi lignified, pruning with scissors is called pruning. The effect of cutting tips is stronger than picking the heart.
1.3 Pull the strong branch towards a space to make up for the deficiency of the bone trunk branch. It can accelerate formation, delay branch growth, improve indoor lighting, and promote flower bud differentiation. In the vertical direction, each main branch should be maintained at 80-90 °; Overlapping branches can be pulled horizontally to the appropriate direction; The spacing between the main branches in the same direction should reach 80-100cm.
1.4 Timely chemical control: When the growth of flourishing trees cannot be inhibited after various summer pruning measures are taken, it is necessary to spray 200-300 times of paclobutrazol or 180-200 times of PBO in a timely manner for control. The principle of spraying only flourishing shoots should be followed at intervals of half a month. Generally, spraying 2-3 times of flourishing trees can achieve good inhibitory effects.
2. Timely fertilization to increase tree reserves
It is usually carried out from the end of May to early June, which is completed within half a month after fruit picking. Because sweet cherries begin to differentiate into flower buds about 10 days after fruit picking. The best type of fertilizer is quick acting fertilizer that contains multiple nutrients. Organic and inorganic fertilizers containing multiple elements, such as decomposed human feces and urine, compound fertilizers, and compound microbial fertilizers. The dosage depends on the type of heat and fertilizer used. The general amount of fertilizer used for large trees is pure sulfur based compound fertilizer (16-14-20S, 17-17-17S, etc.), with 1-1.5 kilograms per plant applied to the resulting trees; Application of microbial inoculants (organic matter ≥ 15%, effective live bacteria 50 million/g, nitrogen 13 phosphorus 4 potassium 8) 0.5-1 kg/plant. Radial trench construction can also be used.
2.1 Early application of base fertilizer is recommended in early September. At this time, the ground temperature is still high, and the root system can absorb sufficient nutrients during the second growth peak. Moreover, after ditching and rooting, it will promote the growth of many capillary roots. Adequate storage of nutrients is a favorable guarantee for the development of flower buds, flowering and fruiting, and the first rapid growth of fruits in the coming year.
2.2 Trench application of base fertilizer: The ditch is 40cm deep and 60-100cm wide, with rotation between plants and rows. According to the target of producing 2000kg per mu of 667 fruits, 2500-3000kg of decomposed pure chicken manure, duck manure, and pig manure are applied, and 70-80kg of high-quality potassium sulfate compound fertilizer is mixed with the soil before watering. For iron and zinc deficient garden slices, 25kg of ferrous sulfate and 15kg of zinc sulfate per 667 acres are mixed with organic fertilizer and fermented before application.
2. 3 foliar topdressing
Within one week after harvest, in combination with pest control, spray 0.3% - 0.5% potassium dihydrogen phosphate+0.5% urea once or twice to delay defoliation and promote flower bud development.
3. Prevention and control of diseases and pests
3.1 The key period for the prevention and control of mites, caterpillar pests, and mites is before awning, and avermectins can be sprayed; Caterpillar can be sprayed with pyrethroid pesticides. Peach leaf cicadas, also known as floating and sinking seeds, are the main disease in the later stage of cherry growth. They are most severely damaged from July to September, with yellow and white spots on the damaged peach leaves. In severe cases, the entire leaves wither and fall off early, leading to weakened tree vigor, affecting flower formation, and reducing the yield of the following year. Can spray 20% fenvalerate emulsion 3000 times and 2.5% deltamethrin 2500-3000 times. In addition, fungicides such as imidacloprid, abamectin, and chlorpyrifos can also be used for prevention and control.
3.2 The prevention and control period of bacterial perforation disease and leaf spot disease is mainly from leaf spreading to the rainy season. Agricultural streptomycin 1000 times solution plus thiophanate methyl or Dasheng M-45 600 times solution can be sprayed alternately every 10-15 days, which can prevent disease and significantly improve the smoothness of fruit surface.
3.3 Gum bleeding should be promptly removed from the gummy area of the tree after rain, and coated with quicklime powder or methylthiophene paste before wrapping it with a thin film. Regularly inspect and prevent as it occurs.
4. Irrigation
After fruit harvesting, the main process is flower bud differentiation. In order to restore the tree body and ensure normal flower bud differentiation, fertilization and irrigation should be carried out immediately after harvesting. However, the amount of irrigation should be based on the moisture content of the soil. Short term drought after irrigation is beneficial for flower bud differentiation. During the growing season of sweet cherries, excessive irrigation is not allowed, and soil moisture is generally maintained at around 70% of the field capacity.
4. The root distribution layer of sweet cherry for drought prevention and drainage is shallow, and it is afraid of drought and waterlogging. During drought, it is necessary to irrigate with small water frequently to maintain stable soil moisture content. Sweet cherry trees are most afraid of waterlogging. After waterlogging, yellow leaves, wilting, dead branches, poor tree growth, reduced yield, and even dead trees may appear, resulting in uneven orchards and lower yield per unit area. Aggravate the occurrence of gum flow disease. So, the sweet cherry orchard must have unobstructed drainage to ensure that it is completely drained within 2 hours after rain, and to try to manually drain it to ensure that there is no accumulated water in the garden. Before the rainy season arrives, drainage ditches should be dug, and plots with a history of waterlogging should be ridged for cultivation. Each time the soil is raised 5cm, the ridges can be gradually raised.