Detailed Guide to the Latest Cultivation Techniques and Methods for Rose Apple
The rose apple is a fine fruit tree and garden landscaping tree in humid tropical regions, also known as water rose apple, fragrant fruit, bell fruit, etc. It is an evergreen arbor plant of the genus Syzygium in the family Myrtaceae, native to Southeast Asia. Wild rose apples grow in the Hainan region, and cultivated rose apples are grown in South China. It can be planted as a windbreak plant, and its fruit is edible. Now let us take a look at the cultivation techniques for rose apple!
Growth Habits of Rose Apple
Rose apple is distributed in Indochina, Malaysia, Indonesia and other places. It is cultivated in Taiwan, China, Fujian, Guangdong, Guangxi, Guizhou, Yunnan, Hainan and other provinces and regions of China, commonly found wild in South China, and also cultivated for food. It is a water-tolerant plant that prefers warm and hot climates and belongs to tropical tree species. It likes to grow by riversides and in river valley wetlands, prefers light, and tolerates drought, barren conditions and high-temperature drought. It has low requirements for soil, a well-developed root system, rapid growth and strong adaptability, and the best soil is fertile, deep and moist.
Cuttage Propagation of Rose Apple
1. Preparing the cutting bed: In the nursery land, make a cutting bed with a bed length of 8-10 m, bed width of 1.2 m, and bed ditch depth of 0.4 m, then spread coarse sand about 10 cm thick in the cutting bed as a drainage layer, and then evenly fill the cutting bed with 1/3 humus soil and 2/3 fine sand to a thickness of 15-20 cm. Such a cutting bed has good water permeability and aeration. In particular, humus soil has a higher water content than fine sand and also has fertility, which is beneficial to cutting rooting and growth. Before cutting, disinfect the cutting seedling bed with 1.0% potassium permanganate solution.
2. Cutting the cuttings: Cuttings should be selected from plants with strong tree vigor, excellent varieties and no pests or diseases. Generally, full-developed 1-year-old branches are selected, and 2-3-year-old old branches can also be used. However, poorly developed leggy branches and overly old branches that are difficult to root should not be used. Cuttings are cut into 15-20 cm lengths. The upper end of the cutting is cut into a flat surface, and the lower end is cut with a sharp knife into a half-moon shape; a straight cut is unfavorable for rooting. The cuttings should have half the leaves removed or all leaves removed while retaining the petioles.
3. Treating the cuttings: Immediately after the cuttings are cut, soak the lower ends of the cuttings in a 50 microliters/liter naphthaleneacetic acid solution, and they can be cut after 6-8 hours; or soak them in a rooting powder at a concentration of 50 microliters/liter for 0.5-1 hour; or soak them in 500 microliters/liter indolebutyric acid for 10 seconds. All of these can better promote rooting.
4. Management after cutting: After cutting, water should be sprayed in a timely manner according to specific conditions, so that the soil water content is maintained at 40%-50% of saturated water capacity. When the temperature is too high, the film should be uncovered and water sprayed to lower the temperature and preserve moisture. After cutting, rooting, sprouting and leaf expansion can occur in 1-2 months, and at this time attention should be paid to strengthening pest and disease control. After 2-3 months, timely foliar topdressing should be carried out with 0.3% urea plus 0.2% potassium dihydrogen phosphate, and after 2 months, apply thin manure water once as topdressing. The plants can leave the nursery only after the shoots sprouted from the cuttings are more than 30 cm long, more than 0.8 cm thick, and fully mature.
Grafting Propagation of Rose Apple
1. Collecting scions: Rose apple grafting can be carried out throughout the year, but April-November is more suitable, and the survival rate of grafting on rainy days is relatively low. From mother trees with high and stable yield, large fruit, excellent quality and pure quality, cut full-growing, already lignified 1-year-old branches as scions. After collecting the scions, remove the leaves and keep them moist for grafting.
2. Grafting method: For rose apple grafting, the cut grafting method is most commonly used. Specifically, cut the scion well, making the cut surface one long and one short, with a smooth cut surface, then cut the rootstock, that is, cut off the rootstock 20-30 cm above the ground, choose a place where the rootstock bark is thick, smooth and the grain is straight as the rootstock cut surface, and shave off a little. Then cut straight down about 2 cm in the cortex with a little xylem, so that the length and width of the cut correspond to the length and width of the scion. Then insert the cut scion into the rootstock cut, align and press the cambium of the scion and rootstock closely, and then wrap and tie it tightly from bottom to top with a tough and thin plastic strip.
3. Management after grafting: After grafting, water frequently and avoid disturbing the graft union. Those that survive after 3-4 weeks can sprout, and at this time attention should be paid to removing sprouts so that the grafted buds can emerge and grow. Remove the sprouts sent out by the rootstock at any time, apply thin manure water as topdressing and control pests and diseases. After the second flush of shoots grown from the scion matures, the plants can leave the nursery when they are 50 cm above the graft union and 1 cm thick at 2 cm above the graft union.
Seed Propagation of Rose Apple
1. Collecting seeds: Seeds should come from excellent mother rose apple plants with high yield and many seeds. After the fruit is fully mature, harvest it, break open the flesh and take out the seeds. After the seeds are taken out, wash them, float off the unfilled grains, dry them in the shade, and store them sealed in plastic bags.
2. Preparing the seedbed: In the nursery, first deep-plow and rake finely according to plan, make beds 1.2 m wide with 0.5 m wide bed ditches, apply decomposed organic fine fertilizer such as pig and cattle manure mixed with fine sand and burnt soil, and then disinfect with 1.0% potassium permanganate solution.
3. Sowing time: In areas with relatively high winter temperatures, rose apple seeds are best stored for 1-2 months before sowing. This is because the seeds have after-ripening, and fresh sowing has a low germination rate. In Hainan Island, the Leizhou Peninsula and the Pearl River Delta, sowing can generally be carried out in August-September, and further delay in sowing easily leads to cold damage and seedling death. In the northern part of South China, it is suitable to store them until mid-March to April of the following spring for sowing.
4. Sowing method: Seeds stored for 1-2 months should be soaked before sowing. Because their germination rate is relatively low, using 0.1 milliliters/liter gibberellin can promote seed germination, and the soaking time is 6-8 hours. After soaking, evenly broadcast the seeds on the bed surface, then cover with river sand or burnt soil, press slightly, cover with grass, water fully, and set up a shade net. Because the temperature in August-September is still high, the seedbed cannot use agricultural film to preserve moisture, but should use rice straw cover to preserve moisture.
5. Management after sowing: About 1 week after sowing, the seeds begin to germinate. At this time, the grass cover should begin to be removed so as not to bend and thin the seedlings. Before the cold wave arrives, film should be covered on the arch shed to prevent cold.
6. Timely transplanting: Seedlings can be transplanted when they are 5-6 cm tall, but generally they are transplanted after the beginning of spring of the second year, when the survival rate is also high. Seedlings can be graded as large, medium and small and transplanted to grafting beds or planted in nutritional bags for cultivation. The row spacing for transplanting in grafting beds is 25 cm, and the plant spacing is 20 cm. When transplanting seedlings, choose a cloudy day, water immediately after transplanting, and apply thin water fertilizer as topdressing about 1 month after survival.