Flamboyant Tree Seed Propagation Methods and Key Technical Points Explained
Flamboyant tree, also known as flamboyant flower and fire tree, belongs to the Fabaceae family, genus Delonix. As an excellent garden ornamental tree and street tree species, the flamboyant tree is widely planted in southern regions. Its branches are elegant and leaves beautiful, with clusters of red flowers that are brilliant and eye-catching, making it beloved by landscaping departments everywhere. For this reason, we conducted observations on the growth patterns of the flamboyant tree and summarized its seed propagation techniques as follows.
The flamboyant tree is generally propagated by seed. After the fruits mature and are collected, they are sun-dried under the sun until the pods naturally split open, or they are beaten with a wooden stick to release the seeds. The thousand-seed weight is 480-520g. The seeds are stored in gunny bags in a dry, cool, and well-ventilated place, and their viability can be maintained for over 1 year. The seed coat is dense and hard.
Before sowing, soak the seeds in hot water at 80°C with twice the seed volume for 24h (allowing to cool naturally), then wash with clean water, then soak again in hot water at 50°C for 24h, wash clean, and broadcast sow on the seedbed, covering with 0.5-1cm of soil. Pay attention to keeping warm, water once in the morning and evening, and germination begins in about 7-10d. When the seedlings reach 8-10cm in height, transplant them to separate beds, pruning some branches and leaves during transplanting. Seedlings are relatively sensitive to frost; compound fertilizer can be applied early, with less nitrogen fertilizer, and fertilization should stop after autumn. In winter, if the leaves have not yet fallen, they can be removed manually, and plastic film covering or individual plant wrapping can be used to prevent frost.
2. Preparation and Methods Before Sowing
1. Seedbed Preparation
The seedbed should be selected in a flat terrain, with convenient transportation, sufficient sunlight, good ventilation, favorable drainage and irrigation, and loose, fertile sandy loam soil. When making the bed, spread 100kg of superphosphate and 0.5kg of 70% thiophanate-methyl powder per 667 sq m. After plowing and harrowing to form fine soil, mix the superphosphate fertilizer and thiophanate-methyl pesticide evenly with the soil, then make the beds, level the bed surface, and make the bed surface particles fine, uniform, and loose.
2. Seed Collection
Mother trees for seed collection should be selected from robust plants 10~20a old, and seed collection is carried out from late October to mid-December each year. Choose windless, clear weather, climb the tree to collect seeds or knock with a bamboo pole. Because the pods are lignified, they can be placed under the hot sun and broken with a stick to remove the seeds, then placed in a ventilated, dry, and cool place to dry in the shade. The thousand-seed weight of flamboyant tree seeds is about 450~550g.
3. Seed Treatment
The seed shell of the flamboyant tree is hard and not easy to absorb water. During treatment, the seeds are first rinsed clean with clean water, then soaked in warm water at 60~70°C for 12~24h, so that the seeds fully absorb water and swell, and then they can be sown.
4. Sowing Methods
Sowing methods generally use drill sowing or bag propagation. The best sowing time is late March to mid-April. For drill sowing, the plant and row spacing is preferably 10cm x 10cm. After sowing, cover with soil 1~1.5cm thick, cover with rice straw, keep the seedbed moist and prevent weed growth, and water thoroughly. Generally, about 20,000 seedlings can be sown per 667 sq m; for bag sowing, arrange the bags neatly on a prepared seedbed or nursery field with nutrient soil, use a wooden stick 1cm in diameter to insert a hole 1~2cm deep vertically in the center of the bag, then place the seed and cover with soil and press firm, water thoroughly, and provide appropriate shading. Germination begins 4~6d after sowing, with a germination rate above 90%.