Common Above-ground and Below-ground Pests of Peony and Their Control Measures
The peony root is plump and sweet, and combined with the influence of the growing environment, it is very susceptible to damage from above-ground and below-ground pests. So, what common pests affect peonies? How should they be controlled?
1. Above-ground pests
(1) Scale insects
The body is orange-red or reddish-orange, with two generations per year. The females often gather in clusters on leaf stalks or stems and branches to suck sap, causing the leaves to turn yellow and the branch tips to wither, which weakens the plant's growth vigor. When pests are found, the affected branches and leaves can be pruned off and burned; during the larval hatching period, 1000-1500 times diluted dichlorvos or omethoate can be sprayed. To ensure the quality of the medicinal material, pesticides should be used with caution; during the dormant period or before budding in early spring, spraying the branches and trunk with 3-5.5Be° lime sulfur mixture has a good control effect.
(2) Longhorn beetles
This is the "Chinese peony saw longhorn beetle," commonly known as the "woodpecker worm." The adult is cylindrical, and the larva is milky white with a small head and plump body, with one generation every 3 years. From May to June, they hatch into larvae that enter the pith of the rhizome, harming the plant. This is not easy to detect and causes the plant to weaken or die. After years of testing, drilling 3-4 holes in the peony rhizosphere, about 20 cm deep, and placing one tablet of aluminum phosphide in each hole, or placing pest-infested seedlings in a sealed room and fumigating with aluminum phosphide, achieves a kill success rate as high as 100%. Therefore, fumigation with aluminum phosphide is a relatively good method for controlling longhorn beetles. Before the larvae bore in, 20% chlorantraniliprole 3000 times solution can be sprayed for control.
(3) Yellow stinging caterpillar
From mid-July to the end of August, the yellow stinging caterpillar molts from larva to adult, and the whole body is yellow-orange. It feeds on the lower epidermis and mesophyll of leaves, making the leaves become riddled with holes. In severe cases, it eats the entire leaf. After maturing, it enters the soil to spin a cocoon and pupate, and the larva spins silk around the branches and trunk. In autumn and winter, remove the cocoons or smash the cocoons on the tree trunk to reduce the source of insects. In summer, remove and destroy the leaves and stems damaged by the insects, and spray 1000-1500 times diluted dichlorvos on the underside of peony leaves, greatly reducing the larval survival rate.
2. Below-ground pests
(1) White grubs
They cause damage throughout the year, with the most serious damage from May to September. They mainly harm the peony roots, biting them into uneven notches or holes. In severe cases, they can cause the peony roots to die, leading to weakened growth or death of the above-ground parts. Drench the roots with 50% phoxim 2000 times solution or 90% trichlorfon 1000 times solution; per mu (667 sq m), scatter 250 g of 5% phoxim granules on the soil surface, then plow deep into the soil.
(2) Cutworms
Damage is most severe in spring and autumn. They often bite off seedlings at the ground surface or feed on sprouts that have not yet emerged, causing missing plants. They occur more severely in weed-infested plots, with several generations per year, varying with the climate in different places. Generally, the first-generation adults appear in late May. For control, the weeds on which cutworms depend for survival can be cleared. For young larvae, spray 98% trichlorfon crystal 1000 times solution or 50% phoxim emulsifiable concentrate 1200 times solution. For older larvae, mix 30 parts of chopped fresh grass they like to eat with 1 part trichlorfon powder and scatter it in the field in the evening to trap and kill them.
(3) Mole crickets
They mainly gnaw on root bark and bite tender buds and seedlings. Poison bait can be made with soybean cake or wheat bran and scattered in the field in the evening to trap and kill them; they can also be trapped at night with light.
(4) Root-knot nematode disease
Generally, the most root knots form from May to June, and the disease occurs most in the 5-10 cm deep soil layer. It mainly harms peony roots. The disease occurs on the roots, appearing as tumor-like bodies of varying sizes, yellow-white and hard in texture. After cutting open, white glossy nematode bodies can be found. At the same time, it causes the leaves to turn yellow, and in severe cases causes early leaf drop. Apply 80% dichloroisopropyl ether emulsifiable concentrate granules 5-10 cm deep into the holes, 5-10 g per plant, once a year. Root drenching with 1.8% avermectin 1000 times solution can also be used.
The above is the common peony pests and control measures compiled by the Huinong.com editor. Have you all learned them? The above pesticides are for reference only, and I hope they are helpful to you.
Controlling peony pests and diseases
Peony is a flower that many people like very much. The peony, with its national beauty and heavenly fragrance, has long been regarded by Chinese people as a symbol of wealth, good fortune, happiness, and prosperity. Today the editor will share with you peony diseases and their control methods.
The main diseases of peony are:
1. Red spot disease: Small purplish-brown nearly round spots appear on the leaves, then gradually expand into irregular large spots, often with concentric ring patterns, and later mold-like substances grow.
2. Gray mold: This disease occurs on leaves, stems, and flowers. Brown round spots appear on the leaf surface, with irregular ring patterns, and in humid weather gray mold-like substances grow on the diseased spots. Brown patterns form on the flowers, and after the buds are damaged they cannot open or become rotten and brown.
3. Brown spot disease: In the early stage, small purplish-brown spots appear on the leaf surface, then expand to form light brown to dark brown concentric rings.
4. Rust disease: When peonies bloom, small light yellow-brown spots appear on the leaf surface, and soon orange-yellow small pustules appear within the spots. After rupturing, orange-yellow powder is released. In the later growth stage of the peony, fine hair-like structures grow in clusters on the underside of the leaves.
5. Anthracnose: Round or irregular yellow-brown sunken diseased spots appear on the leaf surface, with dark brown edges and small black dots in the middle.
6. Southern blight: This disease occurs at the root crown of the peony. In the early stage, white mycelium forms on the surface of the root crown, and water-soaked brown diseased spots appear. In the later stage, brown sclerotia grow on the diseased spots, and at this time the above-ground part of the plant gradually weakens and dies.
The control methods for the above diseases are: before planting, soak the roots in 500 times 70% thiophanate solution for 10 minutes. After disease occurs, drench the roots with 400 times 50% amobam solution, or spray with 50% carbendazim 800 times solution. For rust disease, spray 300 times sodium rust.
Peonies do not have many pests, mainly scale insects, white grubs, leaf rollers, and so on. White grubs bite the root crown of peonies, and their occurrence is relatively common and serious. When underground pests such as white grubs occur, 5% phoxim granules (2 kg per mu) can be evenly scattered on the soil surface, then turned into the soil (about 20 cm), with good control effect.
The above are the pests and diseases of peony and their control methods.
Comprehensive Control Techniques for Peony Cultivation and Pests and Diseases
Luoyang City is famous throughout the world for peonies. In recent years, in order to expand the scale of peony planting and improve the ornamental value of peonies, Luoyang City has vigorously called for peony planting and provided various services for peony growers. The techniques that should be mastered when planting peonies are introduced as follows:1 Cultivation measures
1.1 Selection and treatment of the planting site
According to the growth habits and ecological habits of peonies, for peony planting it is advisable to choose dry, sunny, non-water-accumulating sandy loam, with a pH value not exceeding 8.2, fertile soil, and no continuous cropping. Before planting, per 667 sq m evenly scatter 150-200 kg of fully decomposed cake fertilizer, 100-150 kg of superphosphate, 10-15 kg of carbofuran or phoxim, and 3-5 kg of thiram or etridiazole, then plow deep 40-60 mm, and level the ground 7-10 days before planting and wait to plant. Before planting, the soil moisture should be moderate, with a water content of 20%-30%. Before planting, carefully check the peony root system, cut off diseased, damaged, and broken roots, then soak the whole plant in a mixed solution of 1000 times methyl isothiophos and 3000 times Luheng No. 1 (or 800 times thiram, 800 times Terilike, 1000 times methyl tolclofos, etc.) for 5-15 minutes, then plant.
1.2 Planting time
Peony planting is best from early September to late September, when the ground temperature is 18-23°C. Too early, with high temperature and high soil moisture, easily causes root rot or autumn sprouting; too late, there are few new roots, and the next year's growth vigor is weak and the plant is easily attacked by pests and diseases. If peonies must be planted from late October to early November when the ground temperature is below 15°C, the root system can be dipped before planting in 100-200 mg/kg indolebutyric acid, ABT No. 1, or other rooting agents, and after planting cover with plastic film, or set up a plastic arched shed 30-50 mm high for covering, and remove it in mid-February of the next spring when the weather turns warm. After early November, peonies should no longer be planted.
1.3 Fertilization and watering
Fertilization in peony fields is mainly based on organic fertilizers such as soybeans, soybean cake, sesame oil residue, rapeseed cake, cottonseed cake, farmyard manure, livestock manure, and human feces, which should be fully fermented and decomposed before application. Chemical fertilizers are generally mixed with organic fertilizers, mainly superphosphate, ferrous sulfate, potassium sulfate compound fertilizer, diammonium phosphate, and so on. Fertilizers with high nitrogen content such as urea and ammonium bicarbonate should not be applied in large amounts. Apply 150-200 kg of cake fertilizer per 667 sq m, 1000-2000 kg of farmyard manure, livestock manure, human feces, etc. per 667 sq m, and 25-50 kg of chemical fertilizer per 667 sq m. When applying fertilizers such as urea and diammonium phosphate, per 667 sq m it should not exceed 8-12 kg. Organic fertilizer is applied after the Beginning of Winter in November and before freezing. Chemical fertilizer can be mixed and applied together with organic fertilizer, or applied separately in mid-to-late March. The peony root system is large and goes deep into the soil, and its drought resistance is relatively strong, so watering is generally not needed. In particularly dry years when watering, the salt content of the water should not exceed 0.4%, and the pH value should not exceed 8.2. It is best to irrigate by furrow infiltration, and flood irrigation should not be used.
1.4 Intertillage and weeding, clearing the garden after autumn
Peony fields should always be kept loose and free of weeds. After rain, loosen the soil and weed in time, and hoe the ground more than 5 times each year. From late October to early November, promptly remove dead leaves and diseased branches and thoroughly clear the garden. After clearing the garden, the dead leaves and diseased branches should be burned or deeply buried.
1.5 Proper shading
In peony plots, some tree species with small crowns, small root systems, few pests and diseases, slow growth, and high economic value can be appropriately intercropped, such as low-growing apricot, persimmon, and so on, which can provide good shading during the intense summer heat and can significantly promote peony growth. For densely planted 1-2 year old peony grafted seedlings, setting up shade nets from mid-to-late May to mid-to-early September for shading can significantly reduce the mortality rate. This habit of peonies is the result of their long-term adaptation to the natural environment in their place of origin.
2 Comprehensive control of pests and diseases
From late January to early February, spray 3°Be lime sulfur mixture or carbendazim 500 times solution. When spraying, cover the entire ground and plants. In early March, scatter 10-15 kg per 667 sq m of insecticides such as methyl isothiophos, phoxim, or carbofuran to kill underground pests such as white grubs and mole crickets; alternatively, drill 2-3 holes around each peony, 15-20 cm deep, and apply 1-2 aluminum phosphide tablets per hole, which also has a good effect on controlling underground pests. In mid-to-early April, before the flowering period, spray carbendazim 1000 times solution to control leaf diseases such as red spot disease. In mid-to-late May, spray carbendazim and pyrethroid insecticides or also use black light lamps to control leaf diseases and adult scarab beetles. After that, spray once every 15-20 days with carbendazim or thiophanate-methyl, equal-strength Bordeaux mixture, chlorothalonil, and other fungicides, used alternately. When spraying, potassium dihydrogen phosphate and other foliar fertilizers can be mixed in, with excellent effect. In mid-to-late August, insecticides such as cypermethrin, phoxim, and isocarbophos should be mixed into the fungicides to eliminate pests and avoid damage by boring into flower buds and branches. Chemical control should continue until mid-to-late September. The number of sprayings can be adjusted according to the occurrence of pests and diseases, but there should be no fewer than 3 sprayings during the entire growing season.
Throughout the control process, prevention should be the main approach, with mass prevention and mass control. In addition, attention should be paid to the application of traditional fungicides such as lime sulfur mixture and Bordeaux mixture. These fungicides have low cost, convenient materials, and good effect. At the same time, attention should also be paid to the application of new fungicides, such as Luheng No. 1 and No. 2, Terilike methyl tolclofos, and so on. Although these fungicides cost a bit more, their control effect is excellent. In addition, appropriately intercropping some tree species such as Chinese scholartree and apricot in peony plots can effectively reduce the occurrence of leaf diseases and promote growth vigor. This may be the result of peonies' long-term adaptation to the natural environment in their place of origin.