What are the control methods for pests and diseases of Trichosanthis Radix?
Trichosanthis Radixpests and diseasesmainly includeTrichosanthes leaf spot disease、root rot、root-knot nematode disease，pestsincludewhite grubs. The following introduces the specific symptoms and control methods of Trichosanthis Radix pests and diseases.
I. Diseases
1. Trichosanthes leaf spot disease: Caused by Cercospora fungi spread through conidia, resulting in repeated reinfection and the death of entire leaves. It begins in June, with the peak period from July to September.
Trichosanthes leaf spot disease
control methods: (1) From autumn when Trichosanthes enters overwintering dormancy until before sprouting in spring, gather and burn fallen leaves and debris; plow early in early spring and bury diseased debris under the soil to reduce the source of primary infection. (2) Select disease-free plants for seed saving and plant away from plots that were affected the previous year; maintain reasonable planting density; strengthen field management to enhance plant disease resistance. (3) Remove diseased leaves in the early stage of the disease; spray once with 1:1:200 Bordeaux mixture in early June; one month later, on a sunny day, spray 58% metalaxyl-mancozeb 500 times dilution, 50% mancozeb 600 times dilution, or similar agents 2 to 3 times, once every 10 days.
2. Root rot: Root rot caused by Fusarium. It occurs in early May and is severe during the rainy season.
Root rot
control methods: Remove diseased plants promptly and disinfect the planting holes with lime; select disease-free plants for seed saving; clean the garden after harvest and burn diseased and residual plants.
3. Root-knot nematode disease: Damages the roots, causing root rot. In severe cases, the plants die.
Control methods: Deep plow the soil; after harvest, turn and sun-dry the soil several times to kill the pests; for soil treatment, combined with soil solarization, apply 10 kg of 5% ethoprophos granules per mu, or 5 kg of 10% isazofos, or 1 kg of 4% isofenphos-methyl emulsifiable concentrate; for treating seed roots, soak the roots in 25% ethoprophos emulsifiable concentrate 500 times dilution or 4% isofenphos-methyl emulsifiable concentrate 800 times dilution for 15 minutes, then dry them before planting; strengthen field management, pay attention to weeding during the growing period, and apply organic fertilizer only after it is fully decomposed.
II. Pests
White grubs: They are the larvae of scarab beetles, mainly active in the soil, damaging the roots of Trichosanthes. They occur severely in soil during rainy summers, with high soil moisture, and where more barnyard manure has been applied.
White grubs
Scarab beetles
Control methods: Apply fully decomposed organic fertilizer to prevent attracting adults to lay eggs; handpick and kill them; when white grub damage appears in the field, dig out the larvae near the root zone of affected plants; drench the plant roots with 1500 times dilution phoxim solution.
(For more knowledge about pests and diseases of Chinese medicinal herbs, please follow the medicinal material cultivation section in the knowledge column of Kangmei Chinese Medicine Network http://www.kmzyw.com.cn/pages/channel_746/.)