Detailed Explanation of Key Technical Points for Softwood Cuttage in Summer
Summer Softwood Cuttage Techniques
Softwood cuttage is also called soft branch cuttage or green branch cuttage. Softwood cuttage is generally carried out in summer. In summer, branches are in a semi-lignified state, relatively tender, with more parenchyma cells and containing more water and soluble organic matter. The cells have strong division and differentiation ability, and are easy to root after insertion. Summer softwood cuttage is a good method for propagating saplings. Many trees such as Chinese juniper, dragon juniper, dawn redwood, boxwood, ginkgo, black locust, and glossy privet can all be propagated by summer softwood cuttage. However, due to high temperatures, strong light, and high evaporation in summer, if the softwood cuttage technique is not properly mastered, it will lead to failure. Therefore, in the process of raising seedlings, summer softwood cuttage propagation should be done well; the following technical points should be noted:
I. Selection of cuttings:
When collecting branches, first choose a good mother tree. Because the condition of the mother tree has a great influence on the rooting of cuttings. Generally, cuttings collected from 4-year-old to 6-year-old mother trees have a higher survival rate. The older the mother tree, the more difficult it is for the collected branches to root. Therefore, when collecting branches, they should be collected from young mother trees, and attention should be paid to the degree of lignification of the branches. For softwood cuttage, it is best to use semi-lignified branches of the current year. Branches that are too tender or too lignified are both unsuitable. After the cuttings are collected, place them promptly in a cool and humid place, or wrap them well with moist material to prevent water loss. Cut the branches into cuttings, and make sure to collect, cut, and insert them at any time. The length of softwood cuttings depends on the characteristics of the tree species and the length of the internodes of the branches. Generally, a length of 1 to 4 internodes, 5 cm to 20 cm, is suitable. The leaves at the upper end of the cutting should be properly retained so as to carry out photosynthesis, produce nutrients and plant hormones, and promote rooting, sprouting, and growth of the cutting. Generally speaking, broadleaf trees retain 2 to 3 leaves. For tree species with larger leaves, the retained leaves should be cut off by 1/2 to 1/3 to reduce transpiration. The upper end of the cutting should be cut flat 2 cm above the bud, and the lower end of the cutting should be cut into a horse-ear-shaped oblique incision below the leaf or axillary bud. To improve the survival rate of cuttage, the base of the cutting can be quickly dipped in 500 ppm to 1000 ppm naphthalene acetic acid, then wrapped well with moist material for later use.
II. Cuttage method:
Summer softwood cuttage should be carried out from the period when new shoot growth is slow to before new shoots stop growing, generally from late May to early September. If there are no special protective measures, it is best to carry out cuttage in the rainy season. Because the rainy season has abundant rainfall and high air humidity, it is beneficial for the rooting of cuttings and improves the survival rate. The cuttage depth is generally 3 cm to 5 cm. After cuttage, the cuttings should be kept upright. The cuttage density is generally 3 cm x 10 cm for coniferous trees, and broadleaf trees can be somewhat sparser, preferably so that the leaves do not overlap. After cuttage, spray water once.
III. Field management:
Softwood cuttage requires relatively high air humidity and suitable moisture content in the cutting bed substrate. In production, the method of spraying water is usually used to make the cutting bed substrate moist. At the same time, a small arched shed should be set up on the cutting bed with plastic film to ensure air humidity. To prevent the shed temperature from being too high, shading measures should be taken, generally with a shading intensity of about 70%. This is not only beneficial for leaf photosynthesis, but also prevents excessive light from causing water imbalance in the cuttings and affecting the survival rate. The temperature of the seedbed substrate should be kept between 22°C and 28°C. Under this temperature condition, the cuttings root most easily. In production, the measures for regulating temperature are mainly through water spraying and shading.
After the cuttings survive, properly loosen the soil and weed around the root zone of the seedlings, and apply 1 to 2 times of saturated composite fertilizer extract as topdressing in combination with watering, so that the cuttings grow more robustly.
I. Selection of cuttings:
When collecting branches, first choose a good mother tree. Because the condition of the mother tree has a great influence on the rooting of cuttings. Generally, cuttings collected from 4-year-old to 6-year-old mother trees have a higher survival rate. The older the mother tree, the more difficult it is for the collected branches to root. Therefore, when collecting branches, they should be collected from young mother trees, and attention should be paid to the degree of lignification of the branches. For softwood cuttage, it is best to use semi-lignified branches of the current year. Branches that are too tender or too lignified are both unsuitable. After the cuttings are collected, place them promptly in a cool and humid place, or wrap them well with moist material to prevent water loss. Cut the branches into cuttings, and make sure to collect, cut, and insert them at any time. The length of softwood cuttings depends on the characteristics of the tree species and the length of the internodes of the branches. Generally, a length of 1 to 4 internodes, 5 cm to 20 cm, is suitable. The leaves at the upper end of the cutting should be properly retained so as to carry out photosynthesis, produce nutrients and plant hormones, and promote rooting, sprouting, and growth of the cutting. Generally speaking, broadleaf trees retain 2 to 3 leaves. For tree species with larger leaves, the retained leaves should be cut off by 1/2 to 1/3 to reduce transpiration. The upper end of the cutting should be cut flat 2 cm above the bud, and the lower end of the cutting should be cut into a horse-ear-shaped oblique incision below the leaf or axillary bud. To improve the survival rate of cuttage, the base of the cutting can be quickly dipped in 500 ppm to 1000 ppm naphthalene acetic acid, then wrapped well with moist material for later use.
II. Cuttage method:
Summer softwood cuttage should be carried out from the period when new shoot growth is slow to before new shoots stop growing, generally from late May to early September. If there are no special protective measures, it is best to carry out cuttage in the rainy season. Because the rainy season has abundant rainfall and high air humidity, it is beneficial for the rooting of cuttings and improves the survival rate. The cuttage depth is generally 3 cm to 5 cm. After cuttage, the cuttings should be kept upright. The cuttage density is generally 3 cm x 10 cm for coniferous trees, and broadleaf trees can be somewhat sparser, preferably so that the leaves do not overlap. After cuttage, spray water once.
III. Field management:
Softwood cuttage requires relatively high air humidity and suitable moisture content in the cutting bed substrate. In production, the method of spraying water is usually used to make the cutting bed substrate moist. At the same time, a small arched shed should be set up on the cutting bed with plastic film to ensure air humidity. To prevent the shed temperature from being too high, shading measures should be taken, generally with a shading intensity of about 70%. This is not only beneficial for leaf photosynthesis, but also prevents excessive light from causing water imbalance in the cuttings and affecting the survival rate. The temperature of the seedbed substrate should be kept between 22°C and 28°C. Under this temperature condition, the cuttings root most easily. In production, the measures for regulating temperature are mainly through water spraying and shading.
After the cuttings survive, properly loosen the soil and weed around the root zone of the seedlings, and apply 1 to 2 times of saturated composite fertilizer extract as topdressing in combination with watering, so that the cuttings grow more robustly.