What types of common pests and diseases affect Danshen (Salvia miltiorrhiza)?

The diseases of Danshen mainly includeleaf blight,root rot,southern blight,root-knot nematode disease,and dodder; the main pest isthe white-winged leafhopper.

Danshen diseases

1. Danshen leaf blight: It mainly damages the leaves. The lower leaves of the plant are affected first, then it gradually spreads upward. In the early stage, brown, round small spots appear on the leaf surface; later the lesions keep expanding, with the center turning grayish-brown. Finally the leaves wither and scorch, and the plant dies.

Danshen leaf blight

Control methods: (1) Select healthy planting material, and soak the seeds in 1:1:100 Bordeaux mixture for 10 minutes before planting. (2) Apply more phosphorus and potassium fertilizer to strengthen the disease resistance of the plants; after rain, open drainage ditches in time to lower the field humidity. (3) In the early stage of the disease, spray with 50% carbendazim 600-fold solution, 65% zineb 600-fold solution, or 50% mancozeb 500-fold solution, at intervals of 10-15 days, for 2-3 consecutive times.

2.Danshen root rot: It damages the roots of the plant. In affected plants, the fine roots first develop brown dry rot, which gradually spreads to the thick roots; a cross-section of the root vascular bundles shows obvious brown lesions. In the later stage, the roots rot, and the aboveground parts wilt and die.

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Danshen root rot

Control methods: (1) Choose high, dry terrain with good drainage for planting; where conditions permit, implement paddy-upland rotation. (2) Strengthen field management, apply more phosphorus and potassium fertilizer to improve the disease resistance of the plants; before the rows close, cultivate and weed in time, and when loosening the soil, scatter Trichoderma preparation at 10-15 grams per sq m.

3.Danshen southern blight: It damages the roots. In the early stage, white silky sclerotia appear from the stem base to the main root near the surface soil layer, and the roots become wet and rotted and are easily pulled out of the soil; in the later stage, the branches and leaves of the aboveground parts wilt and die. When the weather is humid, white mycelium and sclerotia resembling mouse droppings often appear at the stem base of diseased plants.

Danshen southern blight

Control methods: (1) Select healthy, disease-free planting material; implement paddy-upland rotation or rotate with gramineous crops. (2) In the early stage of the disease, dig out diseased plants in time, remove them together with the soil for centralized composting; pour 50% carbendazim 600-fold solution or 50% procymidone 1500-fold solution into the diseased holes; or scatter Trichoderma preparation at 10-15 per sq m and then loosen the soil.

4.Danshen root-knot nematode disease: It damages the roots. After nematodes invade, irregular root galls of varying sizes form on all parts of the fine and thick roots; they are initially yellowish-white with a smooth surface, then turn brown and break apart and rot. After nematode parasitism, the root function is destroyed, causing the aboveground parts of the plant to grow weakly and turn yellow, affecting yield.

Danshen root-knot nematode

Control methods: (1) Implement paddy-upland rotation to reduce damage; choose fertile soil and avoid planting in plots with overly sandy soil. (2) When preparing the land, apply 5% fosthiazate 150 kg per hectare in furrows and then plow it into the soil, or apply it in holes at planting; it can also be applied 1-2 times with irrigation during the growing season, 30 kg per hectare each time.

5.Danshen dodder disease: Dodder has strong vitality and spreads rapidly; it is a rootless vine that twines around Danshen plants with haustoria and survives by absorbing nutrients from within the Danshen plant.

Danshen dodder

Control methods: (1) In combination with deep plowing, bury dodder seeds deep, or implement paddy-upland rotation; when dodder damage is found, remove it early to prevent its spread and seed production. (2) Scatter the biological herbicide "Lubao No. 1" powder at 30-40 kg per hectare or spray 3-5 kg of bacterial liquid.

Danshen pests

White-winged leafhopper: Adults and nymphs suck tissue fluid on Danshen leaves; pale yellowish-white small spots appear on the damaged leaves, and when the damage is severe, the chlorotic areas become dense, causing the leaves to turn pale white.

White-winged leafhopper

Control methods: (1) Clear weeds in Danshen fields and on nearby field edges and ditch edges. (2) Apply pesticide control; imidacloprid, dimethoate, deltamethrin and other agents can be used.