Peony cultivation management in northern China (2)

Peony is a temperate plant, native to northwest China, with a certain hardiness habit. However, although peonies are more hardy, if you want to make peonies bloom in the coming year to winter, management cannot be ignored. So, how should the peonies planted in the northern region be managed in winter? How to control pests and diseases? Gu Ruifang, an expert of Shanxi Agricultural Science 110 and a senior garden engineer of Jinci Park in Taiyuan City, introduced this and asked farmers and friends to continue to pay attention.

Gu Ruifang

Senior landscape engineer of Jinci Park in Taiyuan City, 110 expert of Shanxi Agricultural Science

First, wintering management

In order to ensure that the peony overwinters safely, it is poured with frozen water before and after the frost, and organic fertilizer is applied in combination with the frozen water, which can improve the cold resistance of the peony. Old branches die during wintering and can be updated with new branches. The frozen water must be watered thoroughly and fully, and it is best to plough the ground once after watering.

2. Pest control

1, brown spot disease: peony flowering, especially into the rainy season, peony leaves often appear nearly round brown spots, the edge is not obvious, gradually expanded into nearly round or irregular shape of the large spots, the front and back of the spots are all brown, May to September can be infected, and July, August as the onset period. The disease is mainly based on prevention. Spray 200 times equal Bordeaux liquid once every 2 weeks after flowering, or 50% carbendazim 100 times liquid once every 7 to 10 days. Strengthen daily management, planting density should be moderate, pay attention to timely cultivation in the rainy season, and keep the soil dry.

2, powdery mildew: the incidence is basically the same as brown spot disease, but also into the rainy season disease is obvious (peony is more serious than peony), from the stem gradually to the leaf development, so that the diseased leaves become gray-yellow, stem or leaf surface full of a layer of white powder, leaves curled or fall off. The disease is also mainly based on prevention, spraying 200 times Bordeaux liquid or 0.3 degree stone sulfur compound, 100 Tolbozin or powder rust ning every 2 weeks before the onset of the disease.

3, root-knot nematode disease: root-knot nematode disease is the most important disease that harms the root system of peony, when the disease occurs, the plant growth is dwarfed, the leaves are small, the flowers are small or do not flower, causing early leaf fall, when the disease is severe, the leaves of the peony are all shed in August to September.

Prevention and control methods: (1) 15% of the nasal discharge Weiying granules acupuncture, 5 to 10 grams per building, the depth of the hole is about 10 cm, and the water in the hole is filled after application. It is used in early May, once a year. (2) Sick soil treatment, can be sterilized with noridomin, gram line phosphorus or high temperature. In dry soils, nematodes do not survive easily. (3) In autumn transplantation, remove the insectoma, and soak the root with 0.1% methyl isosalphosphorus for 30 minutes, (4) rotate crops when the harm is serious, and turn it deeply once in 3 to 4 weeks, so that the nematodes are drought and exposed to death.

4, mesozoic insects: appear in July to September, the old peony growth is weak, the leaves are dense, poor ventilation and light transmission is easy to infect insects. Two generations occur every year, the female overwinters, and the eggs are often on the back of the leaves or young shoots, and the leaves and branches are withered in severe cases.

Prevention and control methods: you can use a soft brush to brush lightly, or cut off the affected branches and leaves to burn. Spray 40% Oxidized Leguo 1200 times liquid, 15% Slub particles deep buried and irrigated.

5, red spider: appeared in July and August, strong fecundity, 1 year can breed more than a dozen generations, especially in the high temperature and drought season, breeding more rapidly. Female adults or eggs are used to overwinter in branches, trunks, bark or crevices in the soil. When the damaged leaves are seriously damaged, they appear dense and fine gray-yellow spots or patches, causing the leaves to wither and fall off.

Prevention and control method: 40% trichlorocarbicide 1000 to 1500 times liquid, or 40% oxidized Leguo 1200 to 1500 times liquid.

6. Underground pest: Grubs (larvae of scarab beetles) endanger the root neck position, and can cause the death of the whole plant when severe.

Control method: artificial capture of larvae or adults. When the remaining stems and leaves of the victim are found, the soil is dug up and captured and killed. Roots can be watered with 50% octyl thiophos 1000 times solution when watering.

Third, the maintenance of old peonies

Elderly peonies grow slowly, their respiration and photosynthesis are weakened, their ability to absorb water and nutrients is poorer than before, the buds germinate late, the ability to flower is weakened, the flower diameter is reduced, the cold resistance and disease resistance are poor, and the phenomenon of dead strips is easy to occur in winter and spring. The slowness of the middle age of the old peony is also manifested in that from the bud germination to the spread of leaves, buds and flowers, the old peony is about 1 week later than the mature peony. It can be seen that the whole process of differentiation, development and growth of flower buds in the elderly peony is much slower than that of the mature peony. Old peonies can not leave too many buds and too dense in pruning, too much density will affect the flowering effect, but also affect ventilation and light transmission, increase consumption. At this time, the pruning of elderly peonies is a key technical operation in conservation management. In general, old peonies are the same as prime peonies and undergo the first pruning in mid-to-late March. First, the flower buds on the old branches are selected. The growth potential is weak and affects the ornamental pruning. Because the absorption capacity of the old strip is weak, in general, only 1 branch and 1 bud are left on the old strip, try not to leave branches, and secondly, the soil buds sprouting in the root neck are cut off. The second pruning is very important for the elderly peony, and this pruning should not be too long after the first pruning is over. Generally, fertilization and watering are applied immediately after the first pruning, and the second pruning can be carried out after the middle ploughing. If no buds are determined for the first pruning, the weak strips and weak buds are pruned according to the growth of the plant. In general, the top bud is full, but for the elderly peony, the top bud at this time is not fully developed in the spring environment, so the secondary bud is selected for best retention. The third pruning is generally carried out at the end of May and the beginning of June, when the temperature and ground temperature make the soil bud germinate rapidly, so at the end of May and the beginning of June, the pruning can remove all the excess soil buds to achieve the purpose of saving nutrients, reducing consumption, and facilitating ventilation. For plants that are too senescent, keep some appropriately for renewal.

Although peony has the habit of being dry and afraid of wetness, it still consumes a certain amount of water and nutrients during growth and development. Due to the large gap between the absorption capacity and growth potential of the elderly peony and the mature peony, in order to achieve good cultivation results, the elderly peony should not be too much when fertilizing, and the principle of less application should be adhered to. Generally, more dried manure and fermented hemp residue, high-temperature processed chicken manure, a variety of compound fertilizers are mainly applied, combined with each pruning in the spring, and the water and fertilizer are watered thoroughly in time until about 10 days before flowering. In order to replenish the nutrients consumed due to flowering after flowering, and at the same time, due to the flower bud differentiation stage of peony after flowering, a fertilization and watering is also carried out to restore the growth potential of the plant and promote the flower bud differentiation to be fully and smoothly carried out. In September and October, the plant stopped growing, due to the weakening of the cold resistance of the elderly peony, combined with watering frozen water can be fertilized once, and fertilization before wintering has a certain cold protection effect.

Elderly peonies have the habit of liking cool and heat, should be dry and afraid of wet, in order to make the elderly peonies safely over the summer, often ploughing and hoeing grass is an important measure for conservation and management. Cultivated grass can improve soil ventilation and regulate soil moisture to meet the soil air demand of the elderly peony root system. Due to the reduced disease resistance of elderly peonies, it is necessary to carefully manage them in daily maintenance, regularly spray drugs, and strengthen the prevention and control of diseases and insect pests.

Editor: Shi Huifang Wang Dawei Review: Shen Hongtao

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