What are the main pest control methods for Codonopsis pilosula?

The main pests that occur in Codonopsis pilosula cultivation are: aphids, cutworms, white grubs, mole crickets, and red spider mites. So how should these pests be controlled?

Codonopsis pilosula, also known as Shangdang, Xidang, Dongdang, Ludang, etc., is a perennial herbaceous climbing plant in the Campanulaceae family. Its root is used as medicine. It has functions such as replenishing qi and nourishing blood, harmonizing the spleen and stomach, promoting body fluid and quenching thirst, and clearing the lungs. It originated in Shanxi “Shangdang Commandery” (present-day Changzhi City, Shanxi). It is now cultivated in many places.

Plant characteristics and variety introduction

1. Plant characteristics. The root is conical, fleshy, enlarged at the top, with many stem scars, commonly known as “lion's head”. The twining trailing stem is much branched and can reach about 2 m in height. The young tender parts have fine white hairs; the leaves are alternate, opposite, or falsely whorled, with ovate or broadly ovate leaf blades and a nearly heart-shaped base; the whole cross-section has milky juice and a peculiar odor. The flowers are light green and stalked. The capsule is conical, and the seeds are numerous, small, brown, and glossy; the flowering period is August--September, and the fruiting period is September--October.

2. Variety introduction. At present, there are many Codonopsis pilosula production areas, and the varieties and names are complex. According to regional proximity and quality, the products are divided into five types: Xidang, Dongdang, Ludang, Tiaodang, and Baidang. Among them, Xidang and Dongdang are wild products, and the rest are home-grown varieties.

II. Biological characteristics

1. Growth and development. Codonopsis pilosula prefers a cool climate, and high mountain areas at an altitude of 1800--3000 m are more suitable for its growth.

2. Requirements for environmental conditions. High temperatures are unfavorable for its growth. It has strict requirements for light: seedlings prefer shade, and mature plants prefer sunlight. Codonopsis pilosula avoids continuous cropping, and continuous cropping is prone to pests and diseases. Potato is the best previous crop for Codonopsis pilosula.

III. The control methods for its pests are introduced as follows:

Aphids mostly occur in summer and are severe when the weather is dry. They mainly suck the sap of tender buds and tender leaves, causing them to dry up and die. Control method: spray-kill with 40% dimethoate emulsifiable concentrate at 1500-2000 times dilution. Cutworms, white grubs, and mole crickets often occur at the seedling stage and damage seedling stems and roots, causing missing plants and even reduced yield. Control methods: ① Mix 25 g of chlordane emulsifiable concentrate with 5 kg of stir-fried fragrant wheat bran, add an appropriate amount of water to make a poisonous bait, and scatter it in the field to kill them. ② Irrigate around the root zone with 50% phoxim emulsifiable concentrate at 700-1000 times dilution or 50% 1605 emulsion at 1000 times dilution to kill insects and protect roots. ③ When damage occurs at the seedling stage, use 100 g of 90% crystalline trichlorfon and 5 kg of stir-fried fragrant rapeseed cake to make a poisonous bait for trap-killing. Red spider mites damage seedling and mature plant leaves, sucking sap and causing the plants to become yellow, wilted, and even dry up. Control method: spray-kill with 50% fenitrothion at 1500 times dilution.