Methods for the prevention and control of Angelica sinensis pests and diseases and key technical points

(1) For stem nematode disease (má kǒu bìng), the peak periods of occurrence are in mid-April, mid-June, early September and early November after transplanting; it damages the roots, and an abundance of soil-dwelling pests favours its occurrence. Control methods:

① Per mu, use 3 kg of 3911 granules mixed evenly with 15 kg of fine soil, or 0.5 kg of 20% methyl isofenphos emulsifiable concentrate mixed with 2.5 kg of water and sprayed onto 15 kg of soil and mixed evenly, then broadcast and turn into the soil;

② Regularly drench the roots with a broad-spectrum, long-lasting insecticide; per mu use 250 g of 40% carbendazim suspension concentrate or 600 g of thiophanate-methyl plus 150 kg of water, applying 50 g of the diluted solution per plant, once in early May and once in mid-June.

(2) Sclerotinia rot damages the leaves and occurs readily under low-temperature, high-humidity conditions, with more severe damage in July-August. Control methods: do not practise continuous cropping; starting half a month before the disease appears, spray 50% thiophanate-methyl at 1000 times dilution about every 10 days, for 3-4 consecutive applications.

(3) Insect pests are mainly adults of the wireworm and small cutworms. Control methods: clear away green grass inside and around the field, pile it into small heaps, replace with fresh grass every 7-10 days, and use poisoned bait to trap and kill them.