A Detailed Guide to Peony Flower Pest and Disease Control Methods

The peony has long been known as the "king of flowers." Among cultivated types, it can be divided into over a hundred varieties based mainly on flower color, but peonies are also affected by many pests and diseases. Below, let us look at the methods for controlling peony flower pests and diseases.

Peony Flower Pest and Disease Control Methods

I. Diseases

1. Brown spot disease: Strengthen cultivation management, prune in a timely manner, and ensure the plants have good ventilation and light penetration to avoid excessive moisture that breeds fungal pathogens; promptly prune diseased leaves when found and burn them immediately to reduce sources of infection; during the disease period, spray 50% carbendazim wettable powder at 1000 times dilution, or 80% zineb wettable powder at 500 to 700 times dilution, or 80% mancozeb wettable powder at 400 to 600 times dilution, spraying once every 10 to 15 days. The solution should be sprayed evenly on both the front and back of the leaves, with remarkable results; at the end of autumn, diseased leaves and diseased plants should be collected and destroyed, and in winter the nursery should be cleaned, then 7 to 10 times lime-sulfur mixture should be sprayed on the plant stems to kill the pathogens.

2. Rust disease: When planting peonies, choose a site with high terrain and good drainage; before the disease occurs, spray an equal-amount Bordeaux mixture at 160 times dilution, or scatter 400 times zineb around the plants; when the disease occurs, use lime-sulfur mixture, triadimefon, and other treatments for control; promptly remove and burn diseased plants.

3. Gray mold: Remove and burn diseased plants to reduce sources of infection; in severely affected areas, practice crop rotation or deep plow the nursery land; during the growing season, pay attention to ventilation and light penetration to enhance plant resistance; in the early stage of the disease, spray 0.1% equal-amount Bordeaux mixture once every 10 to 14 days, generally for 3 to 4 consecutive sprays.

4. Violet root rot: Choose dry, well-drained, and loose soil for planting, and apply decomposed organic fertilizer; when diseased plants are found, remove and burn them immediately, or scrape off the decayed parts, then disinfect with 4 to 5 degrees lime-sulfur mixture or mercuric chloride, and replant. Disinfect the area around affected diseased plants with lime or sulfur; in the early stage of the disease, drench the roots of diseased plants with 5% amobam at 1000 times dilution, 500 to 1000 milliliters per plant, and cover with soil immediately after drenching; when dividing and replanting in autumn, soak the roots in 0.1% copper sulfate solution for 3 hours, then rinse clean with water before planting.

II. Pests

1. Cottony cushion scale: Strengthen plant quarantine, and eliminate pest infestations immediately when found. They can be gently brushed off with a soft brush, or the infested branches and leaves can be pruned and burned; during the larval hatching period, spray fluoroacetamide, and during the dormant period spray 3 to 5 degrees Baume lime-sulfur mixture; protect and release natural enemies, such as the Australian ladybird and the large red ladybird.

2. Red spider mite: Weed and compost to eliminate overwintering eggs and reduce the initial pest population; when red spider mites are abundant, spray 20% tetradifon wettable powder at 1000 times dilution (can be mixed with other acaricides) or 40% dicofol emulsion at 2000 times dilution, or 40% omethoate at 1200 to 1500 times dilution. To kill eggs, use 0.3 degrees Baume lime-sulfur mixture; protect and use natural enemies such as ladybirds, green lacewings, and thrips.

3. Scarab beetles: Take advantage of their death-feigning behavior and manually capture adult beetles; use sex attractants to trap and kill them; when the infestation is severe, spray omethoate at 1000 times dilution.

4. Root-knot nematode: This pest is a soil-dwelling pest. When the damage is severe, practice crop rotation, clear weeds in the nursery, and deep plow once every half month to let the nematodes dry out and die; spray 80% dibromopropane at 1.5 kilograms per mu.

5. Mole crickets, cutworms, and white grubs: Deep plow the nursery land at the appropriate time, cultivate carefully, and promptly clear weeds; apply decomposed organic fertilizer; drench the roots with omethoate at 500 to 800 times dilution; when damaged stems and leaves are found, dig open the soil and manually capture the larvae or adults.