Detailed Explanation of Key Points for High-Yield Cultivation Techniques of Madagascar Periwinkle

Madagascar Periwinkle, also known as Ri Ri Cao, Shan Fan Hua, Yan Lai Hong, etc. The whole plant is used medicinally, with anti-cancer and blood pressure-lowering effects. It is mainly used to treat acute lymphoblastic leukemia, lymphosarcoma, giant follicular lymphoma, hypertension, and other conditions. It is mainly produced in Guangdong, Guangxi, Hainan, Yunnan, and other provinces. It is now widely cultivated in areas south of the Yangtze River.

Morphological Characteristics: It is an evergreen perennial herbaceous plant of the Apocynaceae family. It is mostly cultivated as an annual. It grows up to 60 cm tall. The young branches are green or reddish-brown, and it, along with the leaf undersides, calyx, corolla tube, and fruit, are all covered with white soft hairs. The leaves are simple and opposite, oblong or obovate, 4-7 cm long and 2-3 cm wide, with the apex of the midrib extending into a short point. Flowers are 1-2, mostly axillary; the calyx is green, 5-lobed; the corolla is salverform, pink or purplish-red, 2.5-3 cm long, with 5 lobes, 5 stamens, included; 2 carpels, separate, styles connate. There are 2 follicles, cylindrical, 2-3 cm long, containing several seeds.

I. Growth Habits

Madagascar Periwinkle prefers a cool, humid, and sunny environment, is drought-tolerant, and is not cold-tolerant. When planted in areas north of the Yangtze River, the aboveground plants mostly die in winter. It has no strict requirements for soil, and cultivation is best in loose, fertile sandy loam rich in organic matter.

II. Land Preparation and Fertilization

Select a loose, fertile field with good drainage and cultivate it intensively. Apply sufficient base fertilizer in combination with land preparation: apply 3000 kg of farmyard manure, 20 kg of urea, and 50 kg of phosphate and potassium fertilizer per mu. Make raised beds 1.3 m wide, dig drainage ditches well, and wait for sowing.

III. Sowing

Madagascar Periwinkle is propagated by seeds. It is carried out in two steps: raising seedlings and transplanting. Direct sowing is also possible. The sowing period is mostly in spring. Seedling raising: Mix Madagascar Periwinkle seeds with fine sand or plant ash and evenly scatter them on the prepared bed surface, gently loosen the surface soil so that the soil covers the seeds, and water to preserve moisture to promote emergence. After emergence, strengthen field management and cultivate until early to mid-June, when the seedlings have grown 3-4 pairs of true leaves and can be transplanted. The sowing rate is 1 kg per mu. Transplanting: Choose cloudy and rainy weather, and plant Madagascar Periwinkle seedlings on the prepared bed surface at a row spacing of 30×10 cm. Water to preserve moisture to promote survival. Direct sowing: Sow Madagascar Periwinkle seeds directly on the bed surface at a row spacing of 25×20 cm. Place 5-10 seeds in each hole. Water to preserve moisture, and full emergence will occur in about 10 days. When the seedlings are 10 cm tall, thin them, leaving 1-2 seedlings per hole.

IV. Field Management

After Madagascar Periwinkle seedlings emerge fully, pay attention to intertillage and weeding. Water frequently in dry weather and drain promptly in rainy weather. Apply topdressing once before the rows close: apply 10 kg of urea and 10 kg of monopotassium phosphate per mu. When the seedlings are 20 cm tall, begin pinching the tops to promote lateral branch development and increase yield. After that, pinch the tops once a month.

V. Pest and Disease Control

The main disease of Madagascar Periwinkle is damping-off. For control, before the disease occurs, use 1:1:100 Bordeaux mixture or mancozeb for prevention. In the early stage of the disease, use carbendazim for control. For underground pests, use phoxim mixed with poison bait for trapping and killing.

VI. Harvesting and Processing

In the first year, Madagascar Periwinkle is harvested in autumn after the lower leaves of the plants begin to turn yellow. Cut at the stem base 15 cm above the ground with a sickle, dry in the sun, and then it can be sold as medicine. In the second year, it can be harvested 2-3 times. Each harvest can yield 150 kg per mu.