Star anise pest and disease control methods, key points of Chinese medicinal herb cultivation techniques

Diseases

1. Anthracnose. It damages leaves, fruits and seedling twigs. One-year-old seedlings below 0.5m are susceptible. In severe cases, it causes leaf fall, flower drop and fruit drop. Control: select disease-resistant varieties. Clear overly dense stands, promptly remove diseased and pest-infested branches and diseased fruits, and improve the permeability of the stand. At the early stage of the disease, spray with a 0.167% solution of 70% mancozeb wettable powder or a 0.125% solution of 50% carbendazim wettable powder, or a 0.125%-0.167% solution of 80% carbendazim-thiram, spraying once every 7-14 days for a total of 2-3 sprays.

2. Sooty mold. Also known as sooty blotch. It damages branches, young shoots, flowers and fruits, and affects leaf photosynthesis. Control: at the early stage of the disease, spray with a 0.125% solution of 70% thiophanate-methyl wettable powder or a 0.125% solution of 58% metalaxyl-mancozeb wettable powder, spraying once every 7-14 days for a total of 2-3 sprays. Alternatively, mix 40% dimethoate emulsifiable concentrate stock solution with water at 1:1 and spray, preparing it just before use.

3. Ring rot. It damages seedlings. Control: spray 0.5:1:100 Bordeaux mixture (that is, copper sulfate 250g, lime 500g, water 500g) or 1000-fold dilution of 50% carbendazim wettable powder, or 600-800-fold dilution of 50% thiram wettable powder, spraying 2-3 times in succession.

4. Brown spot. Also known as yellowing disease. In severe cases it causes leaf fall or dead branches. Control: at the early stage of the disease, spray with 1:1:100 Bordeaux mixture or a 0.1% solution of 75% chlorothalonil, or a 0.1% solution of 75% thiophanate-methyl, spraying once every 10-15 days for a total of 2-3 sprays.

Pests

1. Star anise looper. The larvae damage leaves.

Control: capture the larvae, dig out the pupae, and use black light traps to kill the adults; use Trichogramma and Telenomus to parasitize and destroy the eggs; use ichneumon wasps, parasitic flies and Bacillus thuringiensis to parasitize and destroy the larvae and pupae. Spray with a 0.1%-0.125% solution of 80% dichlorvos emulsion or a 0.1% solution of 20% fenpropathrin.

2. Leaf beetle. Also known as star anise leaf beetle. Both larvae and adults damage leaves, buds and young shoots.

Control: after rain when humidity is high, spray Beauveria bassiana powder to kill the larvae and adults. Use the leaf beetle's death-feigning behavior, phototaxis, and egg-laying and pupation habits for manual capture and killing. Before the larvae reach the 3rd instar, spray a 0.2% solution of 4.5% bifenthrin or a 0.1% solution of 80% dichlorvos emulsifiable concentrate.

3. Red wax scale. The adults damage the trunk, leaves and branches, and at the same time their secretions and excretions induce sooty mold.

Control: in combination with pruning, cut off infested branches and leaves, burn them in a concentrated manner, and spray with a 0.083%-0.125% solution of 40% profenofos emulsifiable concentrate.

4. Weevil. The larvae bore downward and feed inside the branches, causing the branches to die.

Control: during the disease period, spray with a 0.05%-0.067% solution of 4.5% bifenthrin or a 0.125% solution of 80% dichlorvos emulsifiable concentrate. In May, on humid days without rain, spray weevil Beauveria bassiana once, and use it for 2-3 consecutive years to control weevil damage.