Detailed Explanation of Key Technical Points for Summer Management of Apple Trees
Summer weather is extremely hot and sunlight is very intense, and the management of fruit trees during this period is also very critical. Apple trees are in their growth period during summer, and if management is improper, they will be attacked by pests and diseases or develop excessive vegetative growth. Below, let us take a look at what management technical points apple trees have in the hot summer.
In summer, apple flower buds form, young fruits rapidly expand, pests and diseases occur frequently and cause serious damage, so summer pruning must be done well, along with pest and disease control and other work.
1. Carry out summer pruning in a timely manner
Summer pruning mainly compensates for the shortcomings of winter pruning. Specific methods include pinching tips, promoting flowering, improving fruit set rate, bending branches to open the angle, heading back to promote canopy expansion, twisting shoots to cultivate fruiting branches, thinning branches to improve light penetration, and girdling to moderate growth. In addition, branches with a large opening angle are prone to sprouting water sprouts, and wounds are also prone to sprouting water sprouts, which can easily make the canopy dense and consume nutrients, so they should be removed early when they sprout. In June, for overly dense new shoots, remove upright ones and keep flat or slanting ones, remove weak ones and keep strong ones, which can improve ventilation conditions and nutrient distribution. This enriches the leaf buds in the rear portion to form flower buds.
2. Do a good job in managing bagged orchards
Supplement calcium in a timely manner for bagged apples. Calcium deficiency in fruit can easily cause some physiological diseases, such as bitter pit, water core, fruit cracking, and red spot disease. Choose amino acid calcium or calcium nitrate for foliar spraying 2-3 times. In order to improve the absorption and utilization rate of calcium by fruit trees, add 0.3% boron fertilizer when spraying calcium.
Use fertilizer and water wisely. During the rapid fruit expansion stage and the early coloring stage (June-August), apply phosphorus and potassium fertilizer, humic acid organic fertilizer, and fruit tree special fertilizer containing trace elements, and control nitrogen fertilizer. Adjust flexibly according to tree age, tree vigor, fertility level, and fruit load. This fertilizer is also called fruit-stabilizing fertilizer. The general N : P : K ratio is 1:1:1.6, that is, 52 kg of urea per mu, 90 kg of ordinary superphosphate per mu, and 65 kg of potassium sulfate per mu. Apply fertilizer before or after rain or after irrigation. From June to September, spray foliar fertilizer 3-4 times, using multi-element liquid compound fertilizer, potassium dihydrogen phosphate, etc. Fertilization and spraying during this period are not only a guarantee of high yield and high quality apples in the current year, but also the foundation for stable apple production in the coming year, and must not be neglected.
Check bags regularly and irregularly. After bagging, randomly inspect the growth of bagged fruit from time to time. Especially after each rainfall, open part of the fruit bags from different positions to check the fruit. For those with water accumulation inside the bag and small ventilation holes at the bag corners, appropriately enlarge the bag corners with scissors to drain water and ventilate, so as to reduce humidity inside the bag and prevent the occurrence of black spot and red spot diseases.
3. Prevent diseases and control pests in a timely manner
Summer pests mainly include red spiders, leaf rollers, aphids, scarab beetles, star caterpillars, fruit borers, and stink bugs. Common diseases include early defoliation disease, ring rot, anthracnose, spot disease, mosaic disease, powdery mildew, rust, and canker.