Detailed Explanation of the Key Points of Scientific Cultivation Techniques for Balloon Flower

Balloon flower (Platycodon grandiflorus) is widely cultivated in the river valley areas of Shangri-La County, and especially as prices have risen over the past two years, the planting area has increased year by year. Now I will provide a detailed introduction to the cultivation techniques for balloon flower, for the reference of the many farming households.

1. Site selection and land preparation: after choosing a sandy loam plot with sufficient sunlight, deep soil and good drainage, apply 3000 kg of farmyard manure per mu, plus 20 kg of superphosphate or 15 kg of diammonium phosphate, spread evenly over the land, plow deeply 25-30 cm, level and harrow finely, and make beds 1.2 m—1.5 m wide and 15 cm high, with length determined by the terrain.

2. Use good seed: balloon flower seeds should be selected from seeds over 2 years old and not stale (if seeds are kept stale for one year, the germination rate will drop by more than 70%). The seeding rate per mu is 1.5—2 kg.

3. Soaking seeds to promote germination: soak the balloon flower seeds in warm water at about 40°C, stirring constantly so the seeds are evenly heated, then after the temperature drops to about 20°C, rinse with clean water to remove impurities. Then soak for another 12 hours, or soak the seeds in a 0.3% potassium permanganate solution for 12 hours, then mix evenly with an appropriate amount of moist sand, pile for a few days, and then sow; this can significantly increase the germination rate.

4. Sow at the right time (1) Direct field sowing: plants grown from direct seed sowing have fewer branches, straighter roots and higher quality, and the method is simple, saving time and labor. It is widely used, and direct sowing is mostly carried out in spring. For direct field sowing, drilling is mostly used; make horizontal furrows on the prepared bed surface, 2—3 cm deep, with row spacing of 20—25 cm, mix the treated seeds with 10 times their volume of fine sandy soil, spread evenly into the furrows, cover with soil and press lightly, water after sowing, keep the soil moist before emergence, cover with rice straw or pine needles to increase humidity and keep warm, and seedlings emerge in May of the following year; (2) Seedling transplanting: using the seedling transplanting method allows the selection of good, strong seedlings and adjustment of planting width, which helps increase yield per unit area. Select seeds that are large, plump and free from pests and diseases for raising seedlings; the seed treatment for seedlings is the same as that for direct field sowing. The seedling bed is 1.2-1.5 m wide and 25 cm high; before making the bed, apply base fertilizer and mix it evenly with the bed soil, level and harrow finely, open furrows on the prepared bed surface at 10 cm row spacing, 1.0—1.5 cm deep, sow the seeds, cover with 1 cm of soil and press lightly, cover the top with grass or leaves, water to keep the soil moist; generally seedlings emerge in about 15 days, and after the seedlings emerge, remove the covering. Transplant at the end of autumn after the aboveground part withers or before emergence the following spring; dig up the roots, open horizontal furrows on the transplanting bed at 20-25 cm row spacing and 10—15 cm furrow depth, place the plants obliquely in the furrows at 6 cm plant spacing, cover with fine soil after planting, press lightly and water.

5. Field management: when the seedlings are about 5-7 cm tall, thin and finalize the seedlings in time, thinning out overly dense and weak seedlings, and finalize seedlings at 6-10 cm spacing; combine cultivating, weeding and topdressing. Because balloon flower grows slowly in the early stage, weeds should be removed in time. Generally carry this out 3 times: the first when the seedlings are 7—10 cm tall, the second one month later, and the third one month after that, striving to remove weeds as soon as they appear. During the seedling stage, apply diluted human urine 1-2 times to promote seedling growth. In the mid stage, increase fertilizer at the flowering stage, mainly phosphorus and potassium fertilizer, to prevent excessive nutrient consumption from flowering and fruiting from affecting growth. After winter begins, apply a heavy overwintering fertilizer, and earth up in combination with fertilization; drain in time. Balloon flower fears waterlogging, and soil waterlogging easily causes root rot. During summer high temperatures and heavy rain, drainage ditches should be opened in time to prevent root rot from waterlogging and reduce yield; thin flowers and fruits. The flowering period of balloon flower is relatively long and consumes a large amount of nutrients, affecting root growth. Except for seed fields, thinning flowers and fruits can improve root yield and quality. In production, flower buds can be removed manually, such as cutting off flower buds with a sickle, or spraying paclobutrazol at full bloom to prevent flowering. The plant hormone ethephon can also be used at a concentration of 1000 ppm, sprayed at the flower buds at full bloom, until the flowers are covered with the solution; 1125-1500 kg of solution per hectare can achieve the flower-removal effect. This method is efficient, low-cost and safe to use.

6. Pest and disease control: the main pests and diseases of balloon flower are ring spot disease and sheath blight, which mainly damage leaves. In the early stage of the disease, spray 1:1:100 Bordeaux mixture or 50% carbendazim 1000-fold solution for control. Ulcer disease is prone to occur under humid temperatures, long dew duration and abundant rain; leaves turn brown and the stem turns brown from top to bottom. For control, use 72% agricultural streptomycin sulfate wettable powder 4000-fold solution, applying continuously 3-4 times. For underground pests such as mole crickets, cutworms and white grubs, use trichlorfon poison bait to trap and kill them.

7. Harvesting and processing: Seed harvesting: from August to October, when the capsule shell is light yellow and the top begins to split, and the seeds inside are plump and black after opening, pick in batches. The harvested seeds should not be directly exposed to sunlight; they can be piled in a ventilated indoor place for 3 to 4 days so the seed embryos mature naturally, then sun-dried, removed from the fruit shells, and stored in cloth bags or paper bags in a dry, ventilated place. Seed life is one year, and low-temperature storage is preferable; Root harvesting: harvest by digging in the year of transplanting or the second year of direct sowing. Harvest in late autumn from October to November; first cut off the stems and leaves, dig out the roots, wash the soil off with clean water, drain the water, and while fresh scrape off the cork layer with a bamboo strip, glass piece, porcelain piece or the like, wash clean, then sun-dry or oven-dry. It can also be scraped as soon as it is dug to prevent the outer skin from drying and shrinking, which makes peeling easier.