A new technology for planting Dawo Louye cherries in the high temperature and high humidity mountainous areas of southwest China!

A new technology for planting Dawo Louye cherries in the high temperature and high humidity mountainous areas of southwest China!

Fan Jing and others

Funds: Zaozhuang Financial Aid Fund Project of Luyu East-West Poverty Alleviation Cooperation in Fengdu County "Creation and Demonstration of Small Container Cultivation Techniques of Chinese Cherries" (Feng Wei Nong Group [2021] No. 28), Shandong Provincial Key R&D Program "R&D and Demonstration of Supporting Technologies for Small Container Cultivation of Fruit Trees" (Project No.: 2019GNC20407).

'Dawo Louye' cherry is one of the larger and high-quality varieties of cherries in China, mainly distributed in Shizhong District, Yicheng District and Shanting District of Zaozhuang City, Shandong Province, and was listed as the first cherry resource in Shandong Province in the cherry resource survey organized by Shandong Fruit Research Institute from 1980 to 1982. After 1990, with the widespread cultivation of European sweet cherries in China, the cultivation scale of Chinese cherries gradually shrank due to the shortcomings of small fruits, soft flesh, and intolerance to storage and transportation. However, at the same time, it also has the advantages of early maturity period, strong early fruit yield and simple cultivation technology, especially in facility cultivation and container cultivation, which has the incomparable advantages of sweet cherry. Chinese cherry grafting seedlings mostly use xylem bud grafting or T-shaped bud grafting, because the cherry branch is easy to flow gum after injury, and the survival rate is greatly affected by temperature and humidity, using the method of summer bud grafting, it is the rainy season, the wound is easy to flow gum, the survival rate is not high; autumn (early to mid-August) grafting, although the rainfall is reduced, the temperature is reduced, but the interannual variation of temperature and humidity during this period is larger, it is difficult to determine the specific grafting time, when the rainfall is large, the grafting survival rate is not high; late autumn (late August to September In the first half of the month), due to the large temperature difference between day and night, the wound heals slowly, which is not conducive to survival.

Since November 2019, the author has carried out the 'Dawo Louye' cherry potted experiment in the Lu-Chongqing collaborative poverty alleviation work, and in 2020, the wax-sealed scion seppuku grafting 'Dawo Louye' container seedlings in the facility was successful, overcoming the problem of cherry grafting and seedling raising in Fengdu high temperature and high humidity areas.

1. Basic information of the test site

The experimental site is located in Zhuzi Community, Fairy Lake Town, Fengdu County, Chongqing, at an altitude of 1 050 m. Fengdu County is located in the hinterland of the Three Gorges Reservoir area in the upper reaches of the Yangtze River, which belongs to the subtropical humid monsoon climate zone, with unique climatic characteristics of cold and warm in early spring and cool and rainy in autumn. The annual average temperature is 18.2 °C, the extreme maximum temperature is 42.8 °C, the extreme minimum temperature is -1.3 °C, the annual average rainfall is 1 031.9 mm, the maximum annual rainfall is 1316.6 mm, the minimum annual rainfall is 720.5 mm, the annual average relative humidity is 80%, the maximum relative humidity is 83%, the minimum relative humidity is 73%, the annual average sunshine hours are 1 258.8 h, the maximum sunshine hours are 1 545.3 h, the minimum sunshine hours are 1 045.2 h, and the annual average evaporation is 1 163.6 mm, the maximum evaporation capacity is 1 555.1 mm, and the minimum evaporation is 972.2 mm.

The soil type belongs to purple soil paddy soil, the soil is relatively clayey and heavy, the water permeability and air permeability are poor, the soil fertility is average, and the organic matter content is 2%.

The test site is an east-west double-membrane large arch shed, with a height of 3.1 m, a width of 8 m, a length of 44 m, an area of 352 m2, a transparent plastic film on the ground, a minimum temperature of 5.6 °C in winter, and a relative humidity of 60%~70%.

2 Materials and Methods

2.1 Ingredients

2.1.1 Double-membrane large arch shed

The existing plastic greenhouses in Fengdu County are generally single-film galvanized pipe structure, and the insulation effect is poor at night in winter. The test site is located in a high-altitude mountainous area, and the minimum temperature in winter is about -2 °C, and it is difficult for a single membrane plastic greenhouse to maintain a temperature of more than 5 °C in the severe cold of winter. Therefore, when carrying out this test, a layer of non-drip plastic film was hung in the shed, which effectively improved the thermal insulation performance at night.

Before the seedlings, the ground in the shed was leveled, and the seedling furrow with a width of 100 cm was trimmed according to the length of the greenhouse, with a width of 40 cm and a height of 20 cm. After doing a good job of raising seedlings, use a fine rake to flatten the furrow surface, cover all the seedling furrows with the old shed film that has been withdrawn, and seal the greenhouse film with tape if there are loopholes to prevent leakage into the furrow field when watering. A seven-hole water spray belt is placed at intervals of 3~4 m to facilitate timely sprinkler irrigation when the seedlings are dry in the future.

2.1.2 Rootstock seedlings

The large green leaf cherry has strong adaptability and certain anti-root cancer properties, and can be used as an excellent rootstock for Chinese cherry. From late November to mid-December, dig out the annual large green leaf cherry seedlings, select the robust seedlings with a ground diameter of 0.6~1.0 cm, and cut off the seedling stem and the redundant and overly long root system more than 20 cm away from the root neck, so that they can be successfully planted in a nutrient bowl with a diameter of 16 cm.

2.1.3 Nutrient bowls

Choose a black plastic bowl with a diameter of 16 cm and a height of 18 cm, and leave two drainage holes at the bottom to allow water to flow in and out of the bowl freely.

2.1.4 Nutrient soil

The nutrient soil is prepared with garden soil + decomposed organic fertilizer (rabbit manure is the best), and the ordinary sieve sand net is used to sieve it before preparation, and the soil clods and debris are removed, so that the particles of the two are uniform and fine. Mix the garden soil and rabbit manure according to the volume ratio of 1:1 or 2:1, stir evenly and stack them in the greenhouse for later use. When preparing nutrient soil, chemical fertilizers should not be mixed into it, so as not to damage the root system of seedlings and not conducive to the occurrence of new roots.

2.1.5 K84(根癌灵)

Root cancer is a common disease of cherry seedlings, and it is also an important disease that affects the survival and growth of cherry seedlings.

2.2 Method

2.2.1 Rootstock seedling planting

The roots of the cut rootstock seedlings were immersed in clean water for about 2 h, and then the roots were dipped in 4 times of K84 (root carcinoma) solution, 1/5 of the nutrient soil was loaded at the bottom of the nutrient bowl before planting, and then the rootstock seedlings dipped in K84 were put into the nutrient bowl, and the nutrient soil was filled to 4/5 of the nutrient bowl body, leaving space for later watering.

The planted nutrient bowl seedlings were arranged in the seedling furrow, each row of 6 rows, and the outermost row was about 10 cm away from the ridge.

Water in time after each furrow is full, and use a small submersible pump to spray the nutrient bowl with a nozzle to fill the blank space on the mouth of the nutrient bowl. Then fill the seedling furrow with small water to keep the water depth on the film about 2 cm, so that it can slowly penetrate into the nutrient soil through the water inlet hole at the bottom of the nutrient bowl to ensure that the nutrient bowl seedlings fully absorb water.

2.2.2 Environmental regulation in the shed

Greenhouse cultivation of cherry potted seedlings, the temperature and humidity requirements are not high, the specific management measures are similar to ordinary vegetable sheds, pay attention to the maximum temperature in the shed does not exceed 30 °C, a certain high humidity is conducive to the growth and development of cherry potted seedlings.

2.2.3 Preparation of scion

Collect the sturdy 1-year-old branches on the periphery of the cherry canopy in the peak fruiting period, cut the scion with a length of 8 cm and 2~3 leaf buds for wax sealing, and pay attention to distinguishing flower buds and leaf buds when cutting the scion, so as to avoid all the buds being flower buds, otherwise it will affect the survival. The wax sealing time of scion should not be too early, and it is better to do it within 20 days before grafting. The temperature of the wax solution is controlled at 105~110 °C during wax sealing, and the wax temperature is too high to burn the cortex and budding. After wax sealing, the scion should be spread out in an open space for more than 4 hours, and after it is fully dissipated, it should be packed into a plastic bag for moisturizing and preserving to prevent scion burns during the storage period.

2.2.4 Grafting

The best time for grafting cherry container seedlings in greenhouses is early January, and the seppuku grafting method is adopted. First, cut the rootstock obliquely 10 cm above the basin surface, and then obliquely cut it under the cutting edge, about 2 cm long, and the cutting surface should be as long as possible. Hold the lower end of the scion against the tip of the lower cut, cut it obliquely, and then cut it into a wedge shape with a thick side and a thin wedge on the back of the cut, align the cambium layer on the thick side with the cambium on the side of the rootstock incision, insert it tightly, wrap the incision with a plastic strip with a thickness of 20 μm, a width of 3.5 cm, and a length of 20 cm.

2.2.5 Follow-up management

After grafting, pay attention to keep the potting soil moist, and erase the tiller buds below the grafting interface and the rhizome in time to promote the survival of the scion. Pay attention to keep the temperature of the shed above 5 °C, the relative humidity in the shed is above 30%, once the seedlings are in drought, they should be watered in time to prevent the seedlings from wilting due to water loss.

For seedlings with all buds of flower buds, the flower buds should be erased in time, and the first robust tillers under the interface should be retained at the same time to prevent the whole plant from dying;

When the new shoots grow to more than 10 cm, water-soluble fertilizer should be watered, and the fertilizer type was mainly high-quality water-soluble fertilizer with balanced content of nitrogen, phosphorus and potassium active ingredients, with a concentration of 0.3%, watered once every 15 days, watered once after 3 consecutive times, and then watered with water once and then watered with fertilizer.

Pay attention to the prevention and control of pests and diseases such as green blind bugs, red spiders, and perforation diseases.

3 Effects

The survival rate of the grafted 'Dawo Louye' cherry container seedlings grafted in early January 2021 was 97.3% in early March 2021, and the average height of the seedlings surveyed in mid-May 2021 was 65.2 cm and the ground thickness was 0.6 cm. After the seedlings are grafted, they can be brought out of the nursery with the nutrient bowl in May of the same year, which greatly shortens the seedling cycle, improves the planting survival rate and economic benefits, and provides a short-term and fast project with rapid production results for the idle greenhouses or new greenhouses in winter.