Detailed explanation of Chinese honeylocust seedling cultivation techniques, master the key propagation points

Chinese honeylocust (Gleditsia sinensis), also called "zaojiao", is a deciduous tree of the Fabaceae family, reaching up to 30 m tall. Its wood is solid and is used for making furniture, vehicles, farm tools, etc.; the pods are rich in saponin, and using them to wash silk and valuable furniture does not damage the luster; in traditional Chinese medicine, the pods, thorns, seeds and deformed pods are used as medicine. The pods are warm in nature, pungent in taste, and slightly toxic; their functions are to dispel phlegm and open the orifices, and they are mainly used to treat profuse phlegm with cough and asthma, lockjaw from stroke, epilepsy and other conditions; the thorns of Chinese honeylocust are called "zaojiao thorns", with the function of expelling toxin and draining pus, mainly used to treat carbuncles, swellings and sores, and for conditions where pus has already formed but has not yet ruptured; the seeds inside the pods are called "zaojiao seeds", with the function of moistening the intestines and relieving constipation, mainly used to treat dry-intestine constipation; the deformed pods are called "pig-tooth zaojiao pods", with the same functions as the pods. It can be seen that Chinese honeylocust is a treasure from top to bottom and is a tree species with relatively high economic value, and farmers and places with suitable conditions can all plant it. However, in Chinese honeylocust seedling cultivation, because the seed coat is hard, it is very difficult for the seeds to germinate without treatment. Several technical steps of zaojiao seedling cultivation are introduced here:

I. Seed treatment Select 2-3 year old robust, plump, mature Chinese honeylocust pods, extract the seeds, and remove impurities. Generally, sulfuric acid treatment (soaking in solution) is used on the seeds to remove alkalinity and soften the seed coat. Because the concentration of sulfuric acid differs, the soaking time also differs. With 98% sulfuric acid, soaking for 2.5 hours is enough; with 65% sulfuric acid, soaking for 3.5 hours is needed; with 30% sulfuric acid, soaking for 16-17 hours is required. The amount of sulfuric acid solution used should preferably cover the seeds. During seed treatment, stir once every 15 minutes with a small glass rod. If it is found that about 30% of the Chinese honeylocust seeds have fine cracks in the seed coat, soaking should be stopped immediately, the sulfuric acid solution poured off, and the seeds quickly rinsed with clean water until the pH of the residual water on the seed surface is 7. Next, in a glass container, continue soaking the seeds in warm water at 40°C at 5-6 times the seed volume (they can be placed in a constant-temperature incubator at 35-40°C) for 2-3 days, changing the same volume of warm water twice a day, so that the seeds fully absorb water and swell. It is worth noting that during seed treatment, never touch the seeds directly with your hands.

II. Sand bed pregermination Before sowing Chinese honeylocust seeds, a sand bed is generally used for pregermination. The method is: choose a large germination container, use uniformly sized (0.05-0.8 mm in diameter), cleaned and high-temperature sterilized sand grains (with 65% moisture content) as the sand bed material; the sand bed thickness is 2 cm, with a level surface, but do not press it firm. After the sand bed is prepared, first use tweezers to arrange the Chinese honeylocust seeds neatly on the bed surface, then evenly scatter and cover a layer of loose sand 2 cm thick on top, finally cover with the box lid, and place it in a 5°C illuminated germination box for pregermination. After 3-4 days, when the radicle emerges 1-2 cm, sowing can begin.

III. Bed preparation and sowing For those using solar greenhouses for seedling cultivation, sowing is generally done about 60 days before planting. Prepare the seedling bed 4-5 days before sowing; the bed soil should preferably be neutral loam. After watering thoroughly, disinfect the soil with 10 g of 50% carbendazim per sq m. Then open furrows (5-6 cm deep) for sowing, place the seeds in the furrows with the radicle facing down, with a row spacing of 20 cm and a plant spacing of 10-15 cm, then fill level with soil, press firm from both sides, cover with 2 cm of fine soil on top, and lay plastic film flat over the bed surface. When it is found that 60% of the seeds have broken through the soil, remove the plastic film in the morning.

IV. Seedbed management Before emergence, the daytime temperature should be kept at 25-30°C, and not lower than 15-18°C at night. After emergence, pay attention to ventilation during the day and strengthen heat preservation at night. When the seedlings are 10-15 cm tall and the outside temperature reaches 15-20°C, planting can be carried out. From 5-7 days before planting, ventilate to harden the seedlings, keeping 18-20°C during the day and about 15°C at night. Two days before planting, water thoroughly once to keep the soil ball intact, so as to facilitate lifting the seedlings. After planting, pay attention to heat preservation and cold protection.