Post-harvest management of peach trees cannot be relaxed; these tasks must be done well
After peach trees bear fruit, they consume a large amount of nutrients, and peach harvest happens to coincide with the rainy season. If technical management can be strengthened in time, it can increase the tree's nutrient accumulation, restore tree vigor as quickly as possible, form good flower buds, and create favorable material conditions for improving the peach yield and quality of the next year.
1. Underground fertilizer and water management. Through underground fertilizer and water management, the tree can rapidly absorb and replenish nutrients. The method is: after peach harvest, apply a quick-acting chemical fertilizer in time. For trees in the initial fruiting stage, apply 0.25 kg of urea per tree; for mature trees, apply 0.5 kg of urea per tree. The amount of nitrogen fertilizer used must be controlled to prevent excessive vegetative growth of branches, which affects flower bud differentiation. In July, press in green manure once. In combination with pest and disease control, carry out foliar fertilizer spraying: use a 0.3-0.5% urea solution in July, and a 0.3-0.5% potassium dihydrogen phosphate solution in August-September, with an interval of 15 days each time. In September-October, in combination with deep plowing and expanded tree basins, apply base fertilizer once, mainly fully decomposed farmyard organic fertilizer, supplemented by a three-element compound fertilizer. For trees in the initial fruiting stage, apply 50-100 kg of organic fertilizer and 0.5-1 kg of three-element compound fertilizer per tree; for mature trees, apply 100-200 kg of organic fertilizer and 1-2 kg of three-element compound fertilizer per tree. The fertilization method can be either a circular ditch or radial ditches, with a fertilization depth of 30-50 cm.
After peach harvest, there is generally more rain, so watering may not be necessary. If drought lasts too long, water as appropriate to replenish soil moisture. During the rainy season, drain water to prevent waterlogging, cultivate and weed, and prevent soil compaction. Before the soil freezes, water once with freezing water.
2. Pruning. Through pruning, make the tree well ventilated and light-permeable, promote photosynthesis, and form good flower buds. First, remove excessively dense branches, diseased and pest-damaged branches, split and broken branches, overlapping branches, and thin weak branches to improve light conditions. For upright main branches, soften and open the angle to moderate tree vigor. For upright water sprouts on the back, if there is space for growth, soften or twist the tips to control their growth vigor and train them into fruiting branch groups to expand the fruiting area; if there is no space for growth, remove them. For weak, drooping branches after fruiting, properly retract them to reduce nutrient consumption and promote their renewal and rejuvenation. For long fruiting branches, properly shorten them to train compact fruiting branch groups. At the end of September, pinch the tips of new shoots that have not yet capped once to promote fuller tissue growth.
3. Chemical regulation. For excessively vigorous trees, spray paclobutrazol on the canopy to control vegetative growth and promote flower bud differentiation. The method is: when new shoots reach a length of 30 cm and are about to produce secondary branches, spray the canopy with a 15% paclobutrazol 300-500 times solution 1-2 times.
4. Pest and disease control. The main pests and diseases after peach harvest are bacterial shot hole disease, aphids, leaf miners, red spider mites, etc., and they should be controlled in a timely manner. The control of bacterial shot hole disease should focus on prevention. Starting in early June, spray zinc sulfate lime solution on the leaves, with the ratio zinc sulfate: quicklime: water = 0.5:2:120, once every 15 days, for a total of 4-5 times; aphids can be controlled with a 10% imidacloprid powder 3000 times solution or a 25% aphid and whitefly quick-kill emulsifiable concentrate 2000 times solution; leaf miners can be controlled with a 25% diflubenzuron No. 3 1000 times solution; red spider mites can be controlled with a 20% clofentezine suspension concentrate 3000 times solution or a 1.8% abamectin emulsifiable concentrate 4000 times solution, or a 30% moth and mite spirit 2000 times solution. For gummosis, first, try to avoid mechanical damage to branches and trunks; second, after scraping off the gum on branches and trunks, use a protective agent made of 10 parts quicklime, 1 part lime sulfur mixture, 2 parts salt, 0.3 part vegetable oil, and an appropriate amount of water, and apply it to the affected area or pruning cuts. Whitewashing in autumn can reduce the temperature difference between day and night, prevent freezing injury and sunscald, and also kill pests and diseases on the trunk. The ratio is quicklime: lime sulfur mixture: salt: water = 5:1:1:20, with a little clay. Apply the prepared whitewash evenly to the main trunk so that it does not drip downward. Be careful not to apply it to branch tips, so as not to burn the buds.