Detailed Explanation of Key Points in Cherry Tree Seedling Cultivation Techniques
Cherries originated in the Caribbean region of the West Indies in tropical America and are suitable for growing in tropical and subtropical regions with abundant rainfall, ample sunshine, and suitable temperatures. They are renowned worldwide for being rich in vitamin C and are recognized globally as the “King of Natural Vitamin C” and the “Fruit of Life,” with extremely high cultivation value. Let us now take a look at cherry tree seedling cultivation techniques!
Growth Habits of Cherry Trees
Cherries are fruit trees that prefer light, warmth, moisture, and fertilizer, suitable for growing under climatic conditions with an annual average temperature of 10-12°C, annual precipitation of 600-700mm, and annual sunshine hours of over 2600-2800h. Areas where the period with daily average temperatures above 10°C lasts 150-200d and where the extreme minimum winter temperature does not fall below -20°C can all grow well and bear fruit normally. If the local area experiences frost damage, the cherry orchard site can be chosen on a northwest slope where spring temperatures rise slowly and air circulation is good. Considering that cherry roots are shallow and prone to windthrow, the orchard site should be in a location free from wind damage, and the soil should preferably be loose-textured, deep sandy loam.
Cherry Tree Seedling Propagation Techniques
1. Seedling method: After harvesting cherries, cut through the skin and flesh to remove the pit, wash off the flesh attached to the pit with clean water, then place it in a cool place to dry for 1-2 days before sowing. When sowing, place the pit directly into a shallow pot, and germination occurs approximately 10-30 days after sowing. When seedlings grow to 5-250 cm, transplant them into plastic soft pots. Cherry seeds germinate easily, but germination is not uniform, and seeds produced by some plants often lack viable embryos, with germination rates often below 30%. The seedling method takes longer to reach fruiting age, and quality variation among seedlings is significant.
2. Cutting method: During spring and summer growth periods, select semi-mature healthy branches with a diameter of 0.7-30 cm, each segment 15-500 cm long, with 4-6 leaves attached. Insert into river sand, vermiculite, peat soil, or a mixture of several types, all suitable as seedbed media. Cuttings especially need to remain moist and shaded. After cutting, roots develop in about 1.5-2 months, and transplanting can be done after the root system grows vigorously. If managed properly, the cutting method can achieve a 60-90% survival rate. The cutting method is simple and has the highest success rate.
3. Layering method: Select branches that are two years or older, perform ring barking on the lower part near a node, then place moist moss into a transparent plastic bag and wrap the entire wound, tying both ends. After roots form, cut below the layered portion, and pot it to become a new plant. This is usually done during the vigorous growth period of cherries (late spring to early summer), when rooting is easy. Although rooting is relatively easy, results vary greatly among varieties.
4. Grafting method: Cherry grafting uses cherry seedlings, wild cherry, flowering cherry, etc. as rootstock, with good cherry varieties as scions, carried out in spring before budding. It is best to select rootstock and scion with the same or similar thickness, using cleft grafting or approach grafting. Grafting is the most commonly used method for propagating cherry tree seedlings in actual production.
Cherry Tree Seedling Pruning Techniques
1. For young trees, remove excessively vigorous upright main branches on the central leader and excessively vigorous water sprouts on main branches. For retained main branches and lateral branches on main branches, focus on bending branches to open angles and notching buds. The opening angle for main branches should be 60-70 degrees, and for lateral branches 70-80 degrees. When bending branches, they should be pulled into a straight line, never into a bow shape. Bud notching is generally done in early March before buds sprout, aimed at promoting lateral branch development on main branches.
2. For trees in the initial fruiting stage, 4-7 years old, adjust the tree structure and pay attention to cultivating fruiting branch groups on main branches. First, gradually remove main branches that are too low or too dense, ensuring main branches do not affect each other. Second, appropriately retract branches without branching to promote branching. Third, retract or head back overly weak lateral branches for rejuvenation, and for overly vigorous ones, open angles to moderate growth and promote flower formation.
3. For trees in full fruiting stage, adjust the tree structure well to improve light and air conditions within the canopy. Excessively vigorous upright branches, overly dense branches, overlapping branches, and crossing branches that sprout within the canopy must be firmly removed, opening layer spacing to avoid disrupting tree shape and consuming nutrients. For trees that are too tall, promptly drop the top and open the center, using weak branches as leaders to control canopy height.
Cherry Tree Seedling Fertilization Techniques
1. Base fertilizer: Apply base fertilizer early in autumn, no later than November. Barnyard manure, human and animal manure/urine, and farmyard manure can all be applied. Generally, young trees and trees in the initial fruiting stage are applied with 30-60 kg of human and animal manure/urine per tree or 100 kg of barnyard manure, and mature trees are applied with 60-80 kg of human and animal manure/urine per tree or 200 kg of barnyard manure.
2. Topdressing: Topdressing time is before flowering or during the first rapid growth period of fruit, mainly with quick-acting nitrogen fertilizer, which can increase fruit set rate, promote shoot growth and leaf expansion, and lay a good foundation for flower bud differentiation. If 0.5% urea plus 0.5% boron fertilizer or 600 times monopotassium phosphate is sprayed on leaves 1-2 times in early full bloom, fruit set rate can be further increased.
3. Supplementary fertilizer: Apply supplementary fertilizer after harvest to enhance stored nutrients in the tree and promote flower bud differentiation. After harvest, fruit trees transition from the nutrient consumption stage of flowering, fruiting, and shoot/leaf expansion to the nutrient accumulation stage and begin entering the qualitative change period of flower bud differentiation. Therefore, the types of supplementary fertilizer are mainly quick-acting fertilizers, such as decomposed human manure/urine, soybean cake types, and chemical fertilizers. The application amount can be determined based on tree age, canopy size, and fruit yield. Generally, apply 60-80 kg of decomposed human manure/urine per tree, or 2.5-3 kg of decomposed soybean cake, or 1.5 kg of ammonium sulfate, or 0.5-1 kg of urea. Foliar spraying can also be used.