Rapid cultivation of Ball-shaped large-leaf Populus tomentosa by long Branch cutting

Euonymus tomentosa, also known as holly spear, is an evergreen shrub or small tree of Celastraceae. The general plant height is 60~90cm, and the highest is 3m. Populus tomentosa with dense branches and leaves, bright tender leaves, evergreen four seasons, beautiful and elegant, deeply loved by people, is a common ornamental foliage flowers and trees. Populus tomentosa is native to Japan and is widely cultivated in the north and south provinces of China. It likes light and shade, and is suitable for growing on warm and humid climate and loose and fertile sandy loam soil. It is also hardy. Except that unlignified shoots are sometimes frozen in winter, it can survive the winter safely even if planted in the open field in the north.

Populus tomentosa is suitable for planting flower beds, hedges, front courts, steps or dotted lawns and roadsides. Potted viewing can also give people the pleasure of meditation and peace of mind. Because of its strong sprouting power, it is extremely resistant to pruning and shaping. In landscaping, it is often trimmed into wavy, spherical, square and other shapes to decorate the lawn or form color blocks. The ball-club shape is a relatively novel form in the modeling of Euonymus tomentosa. It is a modeling method in which no branches and leaves are left in the aboveground part of Euonymus tomentosa where 50cm is high, and the branches and leaves above 50cm are trimmed into a spherical shape.

In the cultivation of ball-shaped large-leaf Euonymus tomentosa in seedling production, silk cotton wood is generally used as rootstock, big-leaf boxwood is used as scion, and the method of grafting is used. This method requires pre-cultivation of rootstocks and survival of grafting before further pruning, so it takes a long time to cultivate. Through the long-branch cutting and shaping and pruning of Euonymus tomentosa, the grafting link can be saved, the cultivation time can be shortened, the survival rate can be improved, and the ball-shaped Euonymus tomentosa can be cultivated quickly.

1 technique of long-branch cuttage of Populus tomentosa

1.1 prepare the land and make beds

Choose the place with flat terrain, leeward to the sun, near water source and easy drainage and irrigation as cutting land to make a low bed with wide 1200cm and variable length. For the convenience of field operation, the trail 50~80cm can be reserved. After screening, the loess infected by diseases and insect pests was mixed with clean river sand (particle size 0.25~0.5mm), and the soil and sand were mixed evenly as cutting substrates. Loose sandy soil, peat soil, vermiculite, perlite and other seedbed substrates could also be selected, and fine river sand, garden soil and rice bran ash could be mixed at 1:1:1. No matter which kind of cutting substrate should be loose, breathable and well drained, so as to avoid insufficient oxygen supply and affect the growth of adventitious roots. Fill the prepared cutting substrate into the cutting bed to make the bed flat, and the bed surface should be lower than the trail by 20cm. After leveling the bed, disinfect the substrate with 3% ferrous sulfate solution and use the medicine solution 0.5kg/m2. Then use a spray can to spray the water evenly on the substrate, the matrix after adding water is not too wet, it is better to hold it in your hand.

1.2 cutting and treatment of cuttings

In the middle and last ten days of June, the annual branches with strong growth, no diseases and insect pests, semi-Lignification and longer 30cm were selected as panicles. The branches were cut off before 9: 00 a. M., and the cut-back branches should be cut into 50cm-long cuttings in time in the shade, horseshoe-shaped cuttings with an inclination angle of 40 °~ 45 °at the lower part of the cuttings, flat cutting at the upper part, and 1~1.5cm from the upper first leaf, the cut should be smooth, and the stem bark and axillary buds should not be torn. 3-5 pairs of leaves were left in the upper part of the cuttings, and all the lower leaves were removed. Cut cuttings for every 50 into a bundle, the lower cut will be placed neatly, tied up for use. The length of 3cm at the lower end of cuttings was soaked in 1 g 10kg of ABT rooting powder in water, and then it was taken out by 0.5min to be inserted.

1.3 Cuttage

Spray water evenly on the cutting substrate 1-2 hours before cutting, pour the cutting bed thoroughly, and then cut the cuttings according to 10cm × 10cm specifications. The proper depth of insertion is 6~8cm. Before cutting, a small stick equivalent to the thickness of the cuttings can be used to cut out the cutting hole on the substrate, then insert the cuttings into the cutting hole, and then press slightly around the cutting hole with your fingers. After inserting, spray clean water again to clean the leaves, and make the cuttings closely combine with the substrate.

1.4 Shade

In order to prevent strong light, a small arch shed should be built on the border with a bamboo bow after cutting. the top of the shed is about 100cm from the border, and the bamboo bow is covered with a sunshade net to shade the cuttings and keep the seedbed moist, which is beneficial to the healing and rooting of the cuttings.

2 factors affecting the survival of long wood cuttings of Euonymus tomentosa.

2.1 Age of cuttings mother tree

According to the experiment, the older the mother tree is, the more difficult it is for the branches to take root. The rooting survival rate of the branches collected from the 1-2-year-old mother tree is more than 95%, while the rooting survival rate of the mother tree growing for more than 3 years is less than 90%.

2.2 Age of cuttings

According to the experiment, the survival rate of 1-year-old and 2-year-old branches used for cutting is higher. In particular, the cuttage survival rate of one-year-old robust branches sprouting from near roots is the highest.

2.3 fullness of branches

The experiment shows that the more abundant the branches used for cutting, the higher the survival rate of cutting. For long-branch cuttings of Euonymus tomentosa, full and robust branches should be selected as cuttings. In particular, the branches sprouting from the roots are the best, and their plumpness and cutting survival rate are higher.

2.4 temperature

The cuttings of Populus tomentosa can be carried out in spring, summer and autumn, but the cuttings in the middle and last ten days of June can root quickly and grow well. 15 ℃-20 ℃ is suitable for hardwood cuttings in spring, while 25 ℃ is usually suitable for soft wood cuttings in summer. The experiment shows that long-branch cuttings of Euonymus tomentosa are the most easy to root and survive when the temperature is kept at 20 ℃ ~ 25 ℃.

2.5 humidity

After cutting, the suitable moisture is beneficial to the rooting of Euonymus tomentosa, so in addition to maintaining a certain humidity of the substrate, it is necessary to control the relative humidity in the air, especially the soft branch cutting in summer, which requires a high air humidity and an air relative humidity of more than 90%. To keep the cuttings from withering. When the sun is strong at noon, the cutting seedbed needs to be shaded by Reed curtains or sunshade nets. Generally, cuttings can take root about a month after cutting. with the increase of cuttings, shade should be gradually removed, light should be increased, air humidity and substrate humidity should be reduced, which is beneficial to promote root growth and cultivate strong seedlings.

2.6 Lighting

Soft wood cuttings of Populus tomentosa in summer can only take root and survive under certain light conditions. Sufficient light can promote the production of photosynthate in leaves and the rooting of cuttings, especially in the later stage of cuttage. However, in the early stage of cutting, attention should be paid to avoid direct light, to prevent excessive evaporation of water from cuttings, wilting or burning, affecting the growth of hairy roots and roots. Therefore, the shading should be strict at the initial stage of cutting, and the light should be gradually increased after the callus is formed. in the middle of November, when the temperature is lower than 10 ℃, the shade should be gradually removed and covered with plastic film, and the soil should be compacted around to prevent cold.

3 plug-in management

3.1 Control of temperature and humidity

Spray water frequently after cutting, keep the substrate moist, shade the seedling bed when the sun is strong, avoid strong light, keep the temperature in the greenhouse 20 ℃ ~ 30 ℃, relative humidity more than 90%, manage for about a month, and the cuttings begin to take root.

3.2 appropriate fertilization

When the cuttings grow 3-4 new leaves, the resistance increases gradually, and some organic fertilizer can be applied. The method is to put 1 part of cake fertilizer and 10 parts of water into the pool to make it fully mature. When in use, take 1 part of rotten cake and 10 parts of water, irrigate it with a spray can, and apply it once every 15 to 20 days. To be diligent and light, it should be light rather than strong.

3.3 Prevention and control of diseases and pests

The main diseases of Populus tomentosa in winter are moire mouth blight, anthracnose and brown leaf spot, which can be controlled by spraying chlorothalonil or carbendazim 1000 times. Bud blight, root rot and anthracnose which are easy to occur in spring can be sprayed with 1000 times of thiophanate methyl or 50 times of carbendazim. The main pests of Populus tomentosa are long-shell insects, diamondback moth and Populus tomentosa, which should be prevented and controlled. Cutting seedlings are vulnerable to shell insects in the greenhouse, which can be controlled by 20 times of turpentine mixture, and 40% omethoate or 1000 times of isocarbophos are used to control diamondback moth and yellow spot moth in larval stage.

3.4 timely transplanting

The big-leaf Euonymus tomentosa which survived by cutting can be transplanted the following spring. When transplanting, the roots of seedlings should be dipped in mud to improve the survival rate of transplanting. Considering the need of modeling, the plant distance should be increased appropriately. After transplanting, step on the soil and pour enough water.

3.5 shaping and pruning

The most important thing to cultivate big-leaf Populus tomentosa is to sprout in time. After the cuttings survive, sprouts should be wiped in time to maintain its top dominance. When the branches grow to 50cm, they should be coring in time to promote lateral branches. In the future, with the growth of branches, there are no branches and leaves in the aboveground 50cm, and the new shoots above 50cm should be pruned in time to promote the germination of new branches. After pruning, the branches of Euonymus tomentosa are very easy to grow, so the cuttings need to be pruned many times after survival, and the germinating branches should be reasonably chosen to maintain a certain tree shape. In the middle of November, it is necessary to cover the plastic film to resist the cold wind, and before it is trimmed again in the early spring of the next year, the whole plant is modeled through pruning and shaping many times, which can be cultivated into a unique ball-shaped big-leaf Populus tomentosa.