Detailed Guide to Wax Apple Planting Techniques and Management Methods

Wax apple (scientific name: Syzygium samarangense), also known as Java apple, purple rose apple, water rose apple, water pomegranate, heaven peach, nian wu, Java rose apple, and lian wu, belongs to the Myrtaceae family. It is native to India and Malaysia, and the varieties cultivated in Java are especially famous, hence it is also called "Java rose apple." In Hainan, wax apple is called "tian bu," and also "pu tong," because it often falls from the tree with a plop.

Site Conditions for Wax Apple Cultivation

Wax apple is fond of warmth and afraid of cold. Its most suitable growth temperature is 25-30°C, and it will suffer cold damage at 8°C. It has low requirements for soil, but slightly alkaline, moist and fertile clay soil is most suitable (such as paddy fields). Planting in dry land results in low yield and poor quality.

Wax Apple Planting Conditions and Planting Techniques

Wax Apple Field Planting

Wax apple field planting is best done in spring, with a plant-to-row spacing of 4m×5m. Dig large holes, apply large amounts of fertilizer, and plant large seedlings. The holes should be dug 1 meter square, and each hole should receive 50 kilograms of garbage soil and mixed manure. Seedlings should be first-grade seedlings, planted at about 500 plants per hectare, and gradually thinned thereafter.

Wax Apple Shaping and Pruning

After field planting, keep one main trunk, cut off the upper end at 60cm above the ground, and on the trunk above 25 cm from the ground, select and keep 3-4 new shoots with strong growth vigor, even distribution, and about 10 cm apart as the main framework, removing all others except a few as auxiliary branches. At the same time, set up poles to tie the main branches, and shape them at a 45° angle in a natural open-center form. Before bud break at the Spring Festival of the second year, appropriately shorten and cut the weak and slender parts of the newly retained main branches, and after spring shoots emerge, select a strong crown at the tip for expansion. The purpose of shaping and pruning is not only to select a good tree form, but also to ensure ventilation and air permeability, which is especially important after entering the production period. If winter-spring fruit is to be produced, then in February of each year, heading-back pruning must be carried out, cutting off all leaves on the plant, as well as diseased branches, dead branches, overly dense branches, and water sprouts, leaving only two-year-old branches. If half-pruning is used, shading treatment must be adopted.

Wax Apple Fertilizer and Water Management

Wax apple has a high fertilizer demand. In the early stage, apply more phosphorus and potassium fertilizer; during flower bud differentiation, do not apply too much nitrogen fertilizer; after small fruit set, apply heavy phosphorus and potassium fertilizer. Manage water scientifically. Except for keeping the orchard dry in September-October to facilitate flower bud differentiation, keep it moist at other times and irrigate in time to prevent flower and fruit drop. As for annual management, for 1-2 year old trees, generally apply 400-600 grams of nitrogen fertilizer per plant, and for 7-8 year old trees, 1299-1800 grams. Usually before flowering in September-October, apply 50% of the total amount each of nitrogen, phosphorus, and potassium fertilizer, plus 10 kg of compost per plant; during the March-April flowering and fruiting period, apply the total amount of nitrogen fertilizer in divided applications at 50%, and phosphorus and potassium fertilizer at 25% of the total amount; at the end of harvest in June-July, apply another 25% of the total amount of phosphorus and potassium fertilizer. When there is a heavy fruit load, nitrogen, phosphorus, and trace elements can be sprayed on the leaves during the fruiting period. In addition, in some coastal areas where the soil salt content is too high, introducing fresh water to wash the salt and reduce soil salt content can significantly improve soil properties and promote normal plant growth and fruiting.

Wax Apple Flower and Fruit Thinning

Wax apple has a large flower and fruit load. A normal 5-year-old tree generally has more than 2000 flower panicles, and each panicle generally has 11-21 stamens, while commercial economic cultivation only requires about 200 panicles of fruit, and only 6-8 stamens need to be retained per panicle. To accelerate fruit development, enlarge fruit, and improve quality, it is advisable to select and retain flower panicles in good fruiting positions, to avoid abrasions and sunburn, and to remove diseased and inferior fruits. When selecting and retaining, first remove flower panicles growing upward, remove flower panicles at the tips of long branches, and retain as much as possible flower panicles on large horizontal branches, to avoid breaking the fruit stalk or short shoots due to excessive load when the fruit grows larger later. After selecting and retaining flower panicles, remove unnecessary stamens or fruits from these retained panicles. At the same time, use thin string to hang and pull the fruit clusters onto the trellis. In the young fruit stage (bell stage) about 20 days after flowering, bagging should be carried out. Before bagging, the whole orchard must undergo one thorough pest and disease control treatment. If fruit fly density is too high, bagging can be advanced, that is, carried out after flower drop.

Wax Apple Production Period Regulation

To meet market demand, treatments such as flower forcing can be carried out. This shifts wax apple from vegetative growth to reproductive growth. Adjust the production period to between December and April of the following year. Common methods include the irrigation method, root cutting method, girdling method, and branch bending method.

Wax Apple Pest and Disease Control

The main diseases of wax apple are anthracnose and fruit rot, and the main pests are fruit flies, scarab beetles, and scale insects. Wax apple fruit is relatively sensitive to pesticides. Therefore, during production, low-toxicity and high-efficiency pesticides such as zineb, carbendazim, thiophanate-methyl, and fenvalerate can be used for control.

Wax Apple Harvest

Wax apple fruit does not develop purple-red color. It can be harvested when the fruit navel opens. The fruit generally can only be stored for 1 week at room temperature. After sorting and packaging, sell immediately.