A Comprehensive Analysis of the Key Cultivation Techniques for Jiangxiangru
Jiangxiangru, also known as Xiangcai, Xiangrong, etc. The dried aboveground parts with flowers are used as medicine. It is a commonly used traditional Chinese medicine, with effects of inducing sweating and relieving the exterior, dispelling summerheat and resolving dampness, promoting diuresis and reducing swelling, and warming the stomach and regulating the middle. It mainly treats summer colds from drinking cold beverages, headache and fever, aversion to cold without sweating, chest stuffiness and abdominal pain, vomiting and diarrhea, edema, beriberi, etc. The whole plant contains 0.6-1.8 volatile oil and has broad-spectrum antibacterial action. It is cultivated in Liaoning, Hebei, Shandong, Henan, Anhui, Jiangsu, Zhejiang, Jiangxi, Hubei, Sichuan, Guizhou, Yunnan, Shaanxi, Gansu and other places.
I. Growth Habits
Jiangxiangru likes to grow in a warm and humid environment with sufficient sunlight and abundant rainfall. It is not demanding in soil adaptability and can be planted in general soils, but fertile clay soil or red loam soil is preferable. When soil moisture is suitable and the temperature is around 15-18°C, Jiangxiangru seeds emerge 10-15 days after sowing, and the optimum growth temperature is 25-28°C.
After spring sowing, due to the relatively low temperature, growth and development are slow; as the temperature gradually rises, growth gradually accelerates. July-August is the vigorous growth period of Jiangxiangru and also the season for the accumulation of active ingredients. The flowering period is June-July, and the fruiting period is September-October.
II. Site Selection and Land Preparation
Jiangxiangru has strong adaptability. It is advisable to choose loose-textured, wind-sheltered, sunny, well-drained sandy loam soil for planting. Loose red soil on hilly slopes can also be used. Before planting, plow first to allow the soil to fully weather. According to the soil type and fertility status, apply 2000-2500 kg/u of decomposed barnyard manure or compost as base fertilizer. Deeply plow the land 15-20 cm, harrow finely and level it. Generally, two plowings and two harrowings are sufficient. Then make beds 120-150 cm wide and 12-15 cm high, with a bed ditch width of 25-30 cm, and shape the bed surface like a turtle back. Apply 375-450 kg of calcium-magnesium phosphate fertilizer per hectare evenly on the bed surface, then cover it with fine soil from the bed ditch.
III. Sowing
Sowing is suitable in late March to early to mid-April; summer sowing can be carried out in June.
1. Seed Selection and Seed Reservation
Select healthy, disease-free plants and keep them until late September to early October, then harvest when the seeds are fully mature. It is best to harvest on a sunny morning with dew, as the seeds are less likely to fall off. Cut off the roots of the pulled plants, transport them back, and place them on a cement drying yard or drying mat to dry until 80% dry. Then beat the ears with a small stick to make the seeds fall off, winnow out impurities, dry them in the sun, store them in an earthenware jar, and place them in a ventilated and dry place.
2. Sowing Methods
Dibbling, drilling, or broadcasting are all acceptable, but drilling is preferable because it is easier to manage.
When sowing, mix the seeds evenly with plant ash, and choose a sunny or cloudy day. For dibbling, use a plant spacing and row spacing of 3-5 cm × 3-5 cm. For drilling, use a row spacing of 20-25 cm, open shallow furrows 2 cm deep, and evenly sow the seeds in the furrows. The density should not be too high. After sowing, press lightly to make the seeds closely contact the soil to facilitate emergence. The sowing rate is 1.5-2 kg/u. After sowing, cover with about 1 cm of fine soil sifted through a soil sieve and mixed with plant ash or burnt soil ash. After 1-2 weeks, the seeds can sprout.
IV. Field Management
1. Thinning and Final Singling
After Jiangxiangru emerges, it must be thinned in time, thinning the dense and keeping the sparse, thinning the weak and keeping the strong. Generally, the first thinning is carried out when the seedlings are about 5 cm high, followed by 2-3 more thinnings according to growth conditions, and final singling is carried out when the seedlings are 10 cm high.
2. Cultivation and Weeding
During the entire growth period of Jiangxiangru, cultivate and weed 4-5 times. After emergence, pull weeds promptly. Pull them as soon as they appear, following the principle of pulling them small and pulling them out, to prevent weeds from competing with Jiangxiangru for nutrients. Be careful not to damage the root system.
3. Fertilization
The growth period of Jiangxiangru is relatively short, so topdressing should be done in time, mainly with organic fertilizer, and attention should be paid to applying organic fertilizer together with inorganic fertilizer, preferably by band application. On the basis of applying sufficient base fertilizer, carry out the first topdressing when the seedlings are 5-10 cm high, using 75 kg of urea per hectare; carry out the third topdressing before heading, using 120-150 kg of urea per hectare, broadcast on the bed surface, or dissolve urea in water and pour it on, using 11.2 kg of urea per 100 kg of water. After that, apply appropriate topdressing according to seedling growth conditions.
4. Irrigation and Drainage
Jiangxiangru likes moisture but is also afraid of water accumulation around the root system. During the seedling stage, water should not be excessive. If rainfall is too heavy, open ditches in time for drainage to avoid water accumulation in the field. Before and after flowering, Jiangxiangru has the highest water demand. In case of drought, appropriate irrigation should be carried out to ensure sufficient water supply.
V. Pest and Disease Control
Diseases The main disease of Jiangxiangru is root rot. It occurs in the roots and rhizome. In the early stage of the disease, brown patches appear on the roots and root crown, gradually expanding, and the main root and stem base turn dark brown. In the late stage of the disease, the lower leaves of the plant shrink, turn yellow, and die, gradually developing upward. The pathogen belongs to the genus Fusarium in the subphylum Deuteromycotina. It overwinters as mycelium in diseased residues or soil, begins to develop in April, peaks in May, and is reinfected through rain or irrigation water. Control methods: adopt comprehensive agricultural control measures based on "prevention first, integrated control." First, strengthen cultivation management, do a good job of clearing the garden in winter, remove diseased fallen leaves or diseased leaves in time, eradicate weeds, and burn or deeply bury them in a centralized manner to reduce sources of inoculum. During the rainy season, clear ditches and drain well to prevent water accumulation. Remove diseased plants promptly if found to prevent spread. For chemical control, spray with 50% carbendazim 500-fold solution, once every 7-10 days, continuously 2-3 times, or drench the roots with 50% Tuzet wettable powder 1000-fold.
The main insect pest of Jiangxiangru is the black cutworm. It is harmful as larvae. In the young larval stage, it feeds on the tender leaves of Jiangxiangru seedlings, biting them into concave spots, holes, and notches. After the 3rd instar, the larvae burrow into the soil surface and bite off the tender stems, causing the seedlings to wilt and die, resulting in missing plants. It can occur 6-7 generations a year. It begins to appear in mid-to-late February each year. Two reproductive peaks occur in mid-to-late March and early-to-mid April. Late April to early May is the peak damage period. After late June, adults begin to emerge, and the field population gradually decreases. Control methods: during the damage period of older larvae, inspect the field in the morning. If newly wilted or bitten-off seedlings are found, open the surface soil and manually capture and kill the larvae. In the young larval stage, spray with 50% phoxim emulsifiable concentrate 1000-fold solution or 90% trichlorfon crystal 800-fold solution, using 75 kg/u of liquid, once every 7-10 days, continuously 2-3 times. Alternatively, use 50% phoxim emulsifiable concentrate 200 mL/u, mix with 30 kg of moist fine soil to make poisonous soil, and broadcast it along the rows near the seedling root zone in the evening; or use 90% trichlorfon crystal 200 g or 50% phoxim emulsifiable concentrate 200 mL, add an appropriate amount of water, mix with 5 kg of cottonseed cake to make poisonous bait and broadcast it for control, with good results.
VI. Harvesting and Processing
Spring-sown crops are harvested in mid-to-late August, and summer-sown crops are harvested in early-to-mid September. Harvest when Jiangxiangru grows to the full flowering stage, when its volatile oil content is highest.