What are the key points for summer management of sweet cherries?
Autumn is the peak period for fruit tree root growth and also a critical period for the tree to accumulate nutrients, so fertilizer cannot lag behind. Right now, there are many finer points to fertilizing sweet cherries in Yantai. When it comes to the essentials of applying base fertilizer in autumn, the first thing to emphasize is "early." It is generally done in September-October, but early application in September gives the best results...
1. Soil, fertilizer and water management. The fruit development period of sweet cherries is short and requires concentrated nutrients. Pay attention to topdressing before flowering, during fruit development, after harvest and in autumn. The first application should be mainly nitrogen fertilizer supplemented with phosphorus and potassium fertilizer; the second should be mainly phosphorus and potassium fertilizer; after harvest, mainly compound fertilizer, and decomposed human manure and urine or decomposed soybean cake water may also be applied (farmyard manure is best applied in autumn). This fertilization helps flower bud differentiation and increases the yield of the coming year. Irrigate after fertilizing. From after petal fall to before fruit ripening, if the weather is dry, pay attention to irrigation to ensure an adequate water supply; during the rainy season, pay special attention to drainage to prevent waterlogging.2. Summer pruning. The main technical measures for summer pruning of sweet cherries include pinching, twisting shoots, bending branches and thinning branches, using summer pruning to weaken branch growth vigor, promote the formation of short branches and bring fruiting earlier. ① Branch thinning is mainly carried out after harvest, removing large branches that affect ventilation and light penetration and have no value for retention, as well as excessively dense small branches, to improve ventilation and light conditions. ② Pinching should begin in mid-May. For upward-growing branches, pinch once every 20-25 cm of growth, leaving 5-7 leaves; for the extending head of the main branch and lateral branches, top them every 50-60 cm of growth, leaving 40 cm; for vigorous-growing branches on the trunk, bend them to open the angle and top them every 80-90 cm of growth, leaving 60-70 cm.
3. Pest and disease control. The main diseases of sweet cherries include gummosis, European canker (dieback), crown gall, early defoliation disease and root rot. For leaf and fruit diseases, fungicides such as thiophanate-methyl and mancozeb can be used for control; once the rainy season begins, Bordeaux mixture gives good control results. For root diseases, promptly scrape off the diseased spots and tumors and apply a 10-20 times dilution of a fungicide such as Shajunyou for disinfection. The main insect pests of cherries include caterpillars, slug moths, leafhoppers and pear lace bugs. According to the occurrence of the pests, insecticides such as diflubenzuron, imidacloprid and Juanyiqing can be sprayed for control.