A Detailed Guide to Walnut Tree Grafting Methods and Cultivation Techniques
The emergence of grafting technology, on the one hand, makes old trees bloom anew; on the other hand, it also effectively shortens the tree's growth cycle. Walnut tree grafting technology is a great way to shorten the profit cycle. Planting walnut saplings takes at least 8~10 years to bear fruit, while grafted walnuts take only 2~3 years.
How to Graft Walnut Trees
First, select a seedling. Generally, a two-year-old seedling is chosen. Use a grafting knife to cut it off 20 cm from the base of the seedling, with the cut generally 6 cm long.
Then, select the rootstock. Use a grafting knife to remove the old bark from top to bottom, then use a saw to cut the rootstock, cutting it into 13 cm segments.
Next, treat the scion by whittling it into a smooth slope about 4 cm long, make a longitudinal cut at 1/3 of its length, and dip it in a small amount of water, observing the direction in which the water droplets flow.
After that, gently pry open the rootstock by hand to open its cut, place the sloped side of the scion into the cut, then let go so they overlap.
Finally, bind the rootstock and scion together until they are tightly fitted, wrapping with plastic twine to help them heal.
Walnut Tree Cultivation Techniques
1. Site selection and planting: Walnuts are suitable for growing in warm, deep, well-drained sandy loam and black loam soils, and are best planted on sunny slopes and in sheltered spots. Newly planted young trees need ample water and fertilizer, and should be sprayed with New High-Fat Film, which can ensure above-ground water evaporation, sapling water transpiration, isolate pests and diseases, shorten the seedling recovery period, and accelerate root development.
2. Shaping and pruning: To make walnuts bear fruit earlier, with high and stable yields, reasonable shaping and pruning is a very important cultivation technique. The pruning period for walnuts differs from that of ordinary fruit trees; it is done after the fruit is harvested and before the leaves turn yellow. Apply wound-healing antiseptic film promptly to the pruning wounds to promote wound healing and prevent invasion and infection by pathogens.
3. Stabilizing flowers and setting fruit: At the bud stage, young fruit stage, and fruit expansion stage respectively, spray Zhuangguodiling to thicken the fruit stalk, increase nutrient transport, prevent flower drop, improve pollination capacity, increase the fruit-setting rate, accelerate the expansion speed, and ensure high-quality and high-yield fruit. The alternate bearing of the tree body causes an imbalance in the tree's load, which affects both balanced returns and the health of the orchard trees. During the annual flower bud differentiation period, brush Cuihuawang No. 2 once around the trunk, which can promote flower bud differentiation, suppress excessive summer shoot growth, strengthen flowers, and improve pollination capacity and the fruit-setting rate.
4. The main pests of walnuts include: walnut tussock moth, walnut stem borer moth, and walnut fruit weevil. The main diseases of walnuts include: walnut black spot disease and walnut branch blight. Control measures include spraying targeted pesticides to kill them. At the same time, spray the tree body with Hushu Jiangjun, and spray the orchard with New High-Fat Film to retain heat and moisture, ensuring safe overwintering.
The Growing Environment of Walnuts
Walnuts like sunlight, are cold-resistant, drought-resistant, and highly disease-resistant, adapt to growing in many types of soil, prefer fertile and moist sandy loam, like water and fertilizer, and like sun. At the same time, they are not strict about water and fertilizer. Pruning is not advisable after leaf drop and before germination, as it easily causes bleeding. They are suitable for growing in most soils. They like calcareous soil and are commonly found in areas with deep soil layers on both sides of mountain valleys.
Walnuts are widely distributed in China, found in 21 provinces (regions, municipalities) including Liaoning, Tianjin, Beijing, Hebei, Shandong, Shanxi, Shaanxi, Ningxia, Qinghai, Gansu, Xinjiang, Henan, Anhui, Jiangsu, Hubei, Hunan, Guangxi, Sichuan, Guizhou, Yunnan and Tibet. Inner Mongolia, Zhejiang and Fujian and other provinces (regions) have a small amount of introduction or cultivation. The main producing areas are in Yunnan, Shaanxi, Shanxi, Sichuan, Hebei, Gansu, Xinjiang and other provinces (regions).
How Many Years Until Walnut Saplings Bear Fruit
After planting, walnuts usually take 2~3 years, or 5~6 years, or even 8~10 years to enter the initial fruiting stage. How early they bear fruit depends on the variety and cultivation techniques. Precocious walnuts and grafted walnuts can bear fruit in 2~3 years, while late-fruiting walnuts and seedling-grown walnuts take 8~10 years to bear fruit. Generally, they enter the full fruiting stage at around 20 years old, and can be maintained for about 40 years if cultivation conditions are good. Walnuts bloom from April to May, and the fruit ripens from August to September.
The basic technical process for cultivating walnut trees and so on are all covered in the text, but growing saplings cannot be just armchair strategy; what is more important is hands-on practice. Therefore, the above theory can only serve as a guide for everyone's actions, and more experience still needs to be accumulated by everyone themselves.