Cultivation techniques of grafted Container seedlings of Camellia

Cultivation techniques of grafted Container seedlings of Camellia

Fund projects: central Finance Forestry Science and Technology Popularization demonstration Grant Project "Application demonstration of excellent varieties of Camellia in Hubei Province"; School level of Hubei Ecological Engineering Vocational and Technical College in 2017

The scientific research project "breeding and breeding techniques of New varieties of Camellia" (numbered as 2017KY07). Camellia japonica is a general term for many kinds of camellias with ornamental value in Theaceae and Camellia. Camellia is one of the top ten traditional flowers in China, and it is also a valuable flower in the world. Many cities regard camellia as a city flower [Jishan Hua Yao]. With the rapid development of social economy and the prosperity of material life, people's appreciation taste is constantly improving, and families' demand for flowers is also increasing, especially the woody flowers-valuable camellias, which have long-term appreciation value. At present, camellia seedlings are mainly propagated by grafting, but the survival rate of cutting is not high, at the same time, the resistance of cutting seedlings is not strong, and the life span is not long. Camellia grafting is now mainly divided into two kinds, one is to use the high head of Camellia oleifera rootstock to replace camellias to cultivate large seedlings quickly, but because of Camellia grafted seedlings of Camellia oleifera, it is difficult to transplant and survive. Now it is mainly used to transform Camellia camellia low-yield forest into camellia landscape forest and develop tourism, such as Camellia sightseeing tourism in Macheng Wunao Mountain. The other is to use Camellia oleifera bud seedlings as rootstocks, grafting camellias, and then cultivate container seedlings, which is convenient for large-scale cultivation of camellia seedlings and tree-shaped cultivation from an early age.

1 breeding rootstock

"Frosts Descent" after picking old tea fruit, put in the ventilated room after ripening, and so on most of the fruit cracked, manually plucked; screening less than 560 / kg, mildew-free, damaged seeds; water selection to eliminate non-plump seeds, put outside, after the seed surface floating water to dry, moved to a ventilated and cool room for storage, the thickness is not more than 20cm; turn every 2 to 3 days, to the Beginning of Spring.

Preparation of sprouting nursery bed: select the land with leeward to the sun, high terrain, convenient transportation, sufficient water, close to the grafting operation room and nursery to build a budding pond, the pool width is 2m, the length is determined according to the shape of the plot and the number of rootstocks, and the budding pond is made of bricks, about 5 bricks high.

Sowing and sprouting: before and after the Beginning of Spring, the pond was first covered with coarse sand to the third brick (using coarse sand is more permeable and breathable, fine sand is easy to cause rotten roots. Coarse sand can only be used once, because there are seed shells and germs left after one germination, which needs to be screened and disinfected, and the cost is higher than that of using new coarse sand.) the seeds are evenly scattered on the sand surface, the seeds do not overlap, cover the coarse sand to the upper edge of the germination pool, and the germination pool is slightly higher in the center, showing a roof ridge shape along the center of the germination pool. Because the thickness of sand cover is enough, it can not be covered or watered, and in the later stage, if there are true leaves on the seedling rootstock, it can continue to cover the coarse sand, restrain its Lignification, and ensure that the seedling rootstock is semi-lignified, which is consistent with the semi-Lignification of the scion, which is beneficial to the healing of the rootstock, as shown in figure 1.

2 nursery bed preparation

Nursery site selection: choose the plot with sunny, convenient drainage and irrigation, loose fertility, pH 5.5-6.5, yellow soil or red brown soil, convenient transportation and sufficient labor.

Soil preparation and bed preparation: in winter, soil preparation, deep ploughing, freezing to death of insect eggs and weathering; rake flat bed from February to March, bed width 1m, bed height 30~40cm, trail 50cm, bed length 15m-20m, make the bed surface fine and flat.

Container placement: the use of Camellia oleifera special non-textile light matrix container, generally wide 4.5~5.0cm, requires that when cutting the container, make sure that the length of the container is not less than 10cm, the container is too short, the root system is easy to go deep into the seedling bed, resulting in incomplete root mass in the container. There are two ways to put the containers, one is directly placed on the seedling bed, 150-1.8 million per hectare, and the other is placed on a 25cm × 50cm standard disk, with 5 rows of 10 in each row, with a total of 50. The use of acupoint plates is convenient for transfer and seedling emergence, but moisture is partially inhibited, resulting in a higher survival rate than that directly placed on the seedling bed. After the container was placed, it was disinfected with fungicides such as 700-fold methyl topiramate, carbendazim or Dysen zinc and manganese. After disinfection, the container was covered with film for moisturizing and placed for 10 to 15 days.

Setting up a shade shed: after the container is placed, set up a shade shed with a height of 2m and use a shading net of 80%; when covering the sunshade net, pay attention to reduce overlap, because the shade after overlap is too high, resulting in a serious lack of sunlight in the shed, affecting the survival rate and growth of seedlings under the overlapping part of the sunshade net.

3 grafting

Grafting time: from early May to early June. Selection and collection of scions: the semi-lignified spring shoots with full development, strong and full axillary buds were selected, the branch length was 5~10cm, the base thickness was above 0.25cm, and there were at least 1-3 full buds on the branches. The mother tree of ear picking grows healthily and is free from diseases and insect pests, and the scion can also be collected by pruning in the seedlings of 2-5-year-old camellias. Pick up as you pick, and the scions collected should be marked so as to be clonal. If long-distance transportation is needed, it must be collected in the morning and evening or in cool weather, and attention should be paid to temperature control and moisture preservation in the process of transportation.

Anvil and washing anvil: gently dig the rootstock out of the sand bed by hand, install it in a bamboo basket or bamboo blue, rinse the surface sand with clean water, soak and disinfect it with medicine (0.1% methyl topiramate), rinse it with clean water, and finally cover it with a wet towel and store it in a wet place. When raising the rootstock, be careful not to touch the embryo and break the root of the rootstock. Embryo seed is the main source of nutrients before seedling survival.

Ear cutting: full-developed axillary buds or terminal buds were selected from the harvested one-year-old fresh scions, and the lower 0.5cm on both sides of the leaf buds was cut into a thin shape, the length of the cutting surface was about 1cm, and the two sides were required to be uniform and smooth, and then cut off at the upper 0.5cm of the bud tip to form a scion. When cutting ears, the knife is required to be smooth and sharp, and do not return the knife on the cutting surface. All the leaves on the scion can be retained, one bud and one leaf. Put the cut scion in a basin filled with water.

Cutting anvil: put the washed bud anvil flat on the operating table, cut at the cotyledon node at about 2~3cm epicotyl, and then cut longitudinally at the central axis, which is about 1.0~1.2cm deep. The root of the rootstock leaves about 5cm, and the excess part is removed.

Embedding and bandaging: insert the scion into the incision of the rootstock, then wrap the prepared aluminum foil at the interface and gently squeeze it so that the scion is closely combined with the rootstock; then put the grafted seedling into a container basin, cover it with a wet towel and place it in the shade for planting in time, as shown in figure 2.

4 planting of grafted seedlings

The shoots were planted immediately after grafting, and 1 plant was planted in each container. First, the 1cm thick bamboo stick was used to insert a small hole in the center of the non-woven container, and the hole depth was about 5cm. The grafted seedlings were vertically placed into the small holes to expose the aluminum strips and embryo seeds at the interface, and then the grafted seedlings were compacted with bamboo sticks and closely combined with the substrate. After planting, spray the pot with root water, build an arch shed with 2.0m long bamboo slices 1.5m apart, with a height of 0.5m; cover the arch shed with plastic film (note that the film can only be used for one year, the transmittance of the old film is low, affecting the survival and growth of seedlings), and sealed tightly with soil around, as shown in figure 3.

(5) Management at seedling stage in the current year

Moisturizing treatment. From 12:00 to 14:00 every day about 12 days after grafting, tap the upper part of the film with wood strips to make the internal air and water drop into the seedling leaves, maintain the humidity of the leaves, check the bottom film, and repair the damaged ones.

To sprout, weed and remove flower buds at the right time. About 20 days after grafting, the sprouting was removed for the first time and weeds were removed until September. At the same time, the flower buds were removed in time, then watered thoroughly, and after the film was covered for 50 days, combined with weeding and sprouting, 0.2% urea or Ye Miaobao was sprayed on the leaves of the seedlings.

Adjust the temperature and humidity. After grafting for 40 to 50 days, the two films were opened sooner or later in cloudy days for ventilation, ventilation and seedling refining. The two ends of the nursery bed will be uncovered around August 10, and all the plastic film covers will be removed sooner or later in a week or cloudy days. Remove the shade net in early October.

Disease control. It is mainly anthracnose and root rot, combined with removing germination of the film; in the area where the focus occurs, you can also cut a hole in the film, spray the nozzle deep into the shed, and then stick the film with transparent glue after the spray is completed. The drug concentrations used are 1 000 times 70% thiophanate methyl or 1 000 times 50% wettable carbendazim solution, etc., used alternately. After finding the focus, remove the diseased plant container in time, eliminate the bacteria-carrying soil, and then pour 50% wettable carbendazim 800 times solution or 10% copper sulfate solution into the surrounding container and seedbed, as shown in figure 4. 5.

62-year-old seedling management

Graded bed sharing: grafting can be carried out from October of that year to February of the following spring. Grafted seedlings in that year can be divided into four categories: obvious new seedlings (about 65%), one-bud and one-leaf seedlings (that is, scion leaves and buds still exist, 20%), one-leaf non-bud seedlings (that is, scion leaves exist, but no obvious buds, 10%), rootstock dead seedlings (5%). Get rid of the container bag of one-leaf non-bud seedling and dead seedling, the new seedlings and one-bud-leaf seedlings were cultivated separately, and the corresponding management measures were taken respectively. With the implementation of grading bed, more than 95% of the seedlings with one bud and one leaf can develop well and become strong seedlings.

If not strictly graded, the seedlings with one bud and one leaf are basically suppressed and cannot become strong seedlings. The implementation of graded bed sharing can increase the seedling rate by about 20%, while saving land by 15% to 20%, as shown in figure 6. Shading: change the shading net to 50%, and the use time is from June to mid-September.

Weeding: timely artificial weeding container bags and seedbeds of weeds, trail weeds can use herbicides, but should pay attention to medicament damage seedlings. Watering and fertilization: watering according to precipitation, 0.5% compound fertilizer can be applied for 3 times.

7-3-year-old 5-year-old seedling management

Change the basin. After October of the second year to the spring of the third year, change the basin, using diameter 15cm, high 18cm non-textile container, substrate of peat soil 40%, pastoral soil 60%, can be cultivated continuously for 3 to 5 years without replacement, as shown in figure 7.

Shade. The container seedlings can be placed under the forest with a canopy density of 0.4 to 0.5, or 50% sunshade net can be used for July to September.

Trim. The full semi-lignified branches of the same year can be used as scions after pruning in May every year, and the steep long branches can be cut off in September to shape a good crown.