Key Points of Winter Management Techniques for Cherry Trees: Mastering These Is Enough
The cherry tree is a relatively hardy tree that can survive even the cold winters of the north. If you want cherry trees to survive well and have a high fruiting rate, you must do all the work well. The management methods for cherry trees differ at each stage. Winter temperatures are low, and problems increase, so winter management is even more important.
Winter Management Techniques for Cherry Trees
1. Clearing the orchard floor. After the fruit is harvested, the dead branches, fallen leaves, rotten fruit and weeds left under the trees become winter hiding places for many pathogens and pests. Therefore, after pests lie dormant in autumn and before they emerge the following year, personnel should be organized to thoroughly clean them up, either burning them in a centralized pile or composting them at high temperature in the orchard.
2. Turning the soil. In winter, many fruit tree pests overwinter in the soil, such as the peach fruit moth and the jujube looper. For this reason, before the ground freezes, turn the soil under the trees once to a depth of 25—35 cm, so that pests overwintering in the soil are turned out to freeze to death or be eaten by birds, or so that pests on the surface or in the topsoil are turned deep into the soil and smothered to death.
Plowing the orchard helps improve the physical and chemical properties of the soil and also helps kill diseases and pests overwintering in the soil, but care should be taken to damage the roots as little as possible.
3. Pruning. After a year of growth, fruit trees easily develop a disordered shape. To form a good canopy structure, extend the economic lifespan and achieve high quality and stable yields, deciduous fruit trees are best pruned for shape in winter, from late December to January. Generally, young trees and vigorous trees are pruned lightly, while old trees and weak trees are pruned heavily; trees in full bearing age and trees of medium vigor are pruned to regulate the following year's growth and fruiting.
Winter Watering and Pest Prevention for Cherry Trees
In recent years, because there has been less rain and snow in winter and drought has been severe, it is recommended to give the orchard a thorough watering, combined with fertilization. After half a month, water again before flowering, which both alleviates the drought and lowers the ground temperature, helping to delay the flowering time of the fruit trees. Also promptly spray 5-degree lime sulfur mixture, or 1:2.5:200 Be poly-sulfide solution, to sterilize and disinfect the tree body. By “whitewashing”, it is also possible to better reduce the tree's absorption of solar ultraviolet rays and slow the tree's too-rapid warming, so as to delay the flowering time and allow trees in full bloom to be in a more suitable temperature environment for pollination, thereby increasing the fruit-setting rate.
Winter Pruning of Cherry Trees
1. Heading back. Cutting off part of a one-year-old branch is called heading back. Leaf buds must be left below the cut on a headed-back branch. The purpose of heading back is to reduce the number of leaf buds and flower buds on the headed-back branch, strengthen the branch's ability to send out new shoots, lower the position of shoot development and enhance branching ability.
2. Thinning out branches. Removing branches from the base is called thinning out, also known as thinning pruning. Thinning out can reduce branch density within the canopy, improve ventilation conditions in the canopy, relatively concentrate stored nutrients in the tree and promote new shoot growth. After thinning, it inhibits the part above the wound and promotes the part below the wound. Removing useless branches that are thin and weak, diseased or pest-infested, water sprouts, overlapping and densely crowded shade-casting branches can boost the vigor of the remaining branches.
3. Leaving branches unpruned. Not pruning a one-year-old branch and letting it grow naturally. Leaving branches unpruned allows the greatest number of buds to be retained on the branch and moderates the growth vigor of the following year's new shoots. Leaving overly vigorous fruiting branches of water-sprout type or long fruiting branches unpruned can weaken apical dominance and promote the formation of medium and short fruiting branches.
4. Renewal pruning. This refers to heading back perennial branches, also called reduction. Renewal pruning can reduce the total length of branches and trunks, concentrate the supply of nutrients and water to the retained branches, promote the growth of lower branches and is relatively favorable for rejuvenating tree vigor. Its role is to improve light conditions within the canopy, lower the fruiting position, change the extension direction and angle of the extending branch, control the canopy and extend the fruiting years.
Winter Treatment of Pests and Diseases on Cherry Trees
1. Cut off diseased branches. The same applies when treating diseased trees with partial branch and trunk death. At the same time, clean up the roots in the same direction as the dead diseased branches, cut off the rotten roots and apply compound carbendazim or mancozeb, both at 400-600 times dilution.
2. Clean up dead trees. For trees that died from disease, clean them up and remove the soil from the tree pit, while expanding the pit to 100 cm2 and 60 cm deep, filling in 20 cm of soil mixed with manure and 20 cm of new soil, in preparation for replanting trees the following year.
3. Inspect the fruit tree branches and trunks and remove the egg masses of pests on them.
In winter, after the cherries have ripened and been picked, many problems are left behind, so during this period the orchard cleanup work must be strengthened to avoid bacterial infection. Winter pruning is also very important, as it relates to the branch growth and fruiting rate of the coming year, so this part of the work must be done well.