What are some effective tips for preventing powdery mildew in flowers and nursery stock?

What are some effective tips for preventing powdery mildew in flowers and nursery stock.

To prevent disease in flowers and trees inside greenhouses, before raising seedlings and planting in the greenhouse, thoroughly remove all plants inside the greenhouse, clean the greenhouse chamber, and strictly disinfect by means such as fumigation with chemicals. Strictly prevent diseased seedlings from entering the chamber; as far as possible, plant a single variety of flowers and trees in the greenhouse and avoid mixed planting to prevent cross-infection. Before open-field flowers and trees sprout in early spring, the greenhouse can only be opened after thoroughly destroying the diseased plants inside, so as to prevent fungal spores from spreading outside the greenhouse.

Chemical control: during the overwintering period, spray trunks and branches with a diluted lime sulfur mixture at 3-5 degrees Baume. Flowers prone to chemical injury, such as cineraria, must not be treated with it; scatter sulfur powder on the ground, generally using 25-30 grams per 70 sq m, to eliminate overwintering sources of the fungus.

During the growing season, protective fungicides can be sprayed before disease onset, and systemic fungicides should preferably be sprayed after disease onset. According to the disease symptoms, the growth of flowers and trees, the climate conditions and the characteristics of the pesticide, apply the chemical once every 5-20 days, for 2-5 consecutive applications. For flowers and trees in one season, a single systemic fungicide may be applied only 1-2 times; the types of pesticide should be changed frequently to avoid the pathogen developing resistance.

Commonly used protective fungicides include: 50% sulfur suspension concentrate at 500-800 times dilution, 45% lime sulfur mixture crystals at 300 times dilution, 50% thiram wettable powder at 800 times dilution, 75% chlorothalonil at 500 times dilution, and 70% mancozeb at 400 times dilution.

Systemic fungicides include: 50% carbendazim at 500 times dilution and 75% thiophanate-methyl at 1000 times dilution. When the disease is rampant, 15% triadimefon at 1000 times dilution can be sprayed.

Antibiotic types include: 2% antimycin aqueous solution at 200 times dilution and 10% polyoxin (Baolian) at 1000-1500 times dilution.

Other agents also include baking soda at 500 times dilution, which can be sprayed once every 3 days in the early stage of disease onset, for 3-6 consecutive sprays. In addition, baijiu (35% alcohol content) at 1000 times dilution can be used, sprayed once every 3-6 days, for 3-6 consecutive sprays, washing the leaves until there is no white powder left.

For flowers and trees planted in protected areas such as greenhouses and conservatories, in addition to spraying the various chemicals above, fumigants and dust formulations can also be applied. Before planting or after finishing, empty-greenhouse disinfection should be carried out: for every 100 sq m, use 250 grams of sulfur powder and 500 grams of wood shavings, mix evenly, divide into 10 piles, and ignite with red-hot coal balls or charcoal; do not use an open flame, and keep the greenhouse closed for one day and night. During fumigation, strictly guard against fire. Fumigation during the growing period of flowers and trees easily causes chemical injury and should be used with caution. During the plant growing period, before disease onset, use 45% chlorothalonil smoke formulation at 25 grams per 67 sq m, or spray 5%

chlorothalonil dust formulation at 100 grams per 67 sq m

In production practice, the main methods for controlling powdery mildew are as follows:

Choose varieties with mild disease incidence or disease resistance. Different varieties of flowers and trees show significant differences in resistance to powdery mildew. Choosing varieties with mild disease incidence or strong disease resistance for planting is the most economical and effective method of controlling powdery mildew.

When purchasing seedlings, choose disease-free plants. When buying nursery stock, strictly remove infected plants to eliminate sources of disease. When carrying out propagation, cut disease- and pest-free cuttings or root suckers as asexual propagation material. When nursery stock leaves the nursery, chemical control should be applied to strictly prevent diseased nursery stock from being introduced into new areas.

Crop rotation: rotate with non-host flowers and trees for 2-3 years to reduce sources of disease.

Strengthen cultivation management. From late autumn to the overwintering period in early spring of the following year, thoroughly clean the nursery, prune diseased and pest-infested branches and destroy them in a centralized manner; during the growing period, promptly remove diseased branches and leaves, thoroughly clear fallen leaves, prune diseased and pest-infested branches and overly dense branches in the middle and lower parts, and destroy them in a centralized manner; planting should not be too dense, and greenhouses should be ventilated and aired to reduce humidity; promptly drain standing water in fields and flower pots, do not water too much, water from the edge of the pot, and do not splash water on stems and leaves, so as to reduce the spread of the pathogen and the chance of disease onset; apply more phosphorus and potassium fertilizer and less nitrogen fertilizer to make the plants grow robustly, and apply more fully decomposed organic fertilizer to enhance the disease resistance of the plants.

To prevent disease in flowers and trees inside greenhouses, before raising seedlings and planting in the greenhouse, thoroughly remove all plants inside the greenhouse, clean the greenhouse chamber, and strictly disinfect by means such as fumigation with chemicals. Strictly prevent diseased seedlings from entering the chamber; as far as possible, plant a single variety of flowers and trees in the greenhouse and avoid mixed planting to prevent cross-infection. Before open-field flowers and trees sprout in early spring, the greenhouse can only be opened after thoroughly destroying the diseased plants inside, so as to prevent fungal spores from spreading outside the greenhouse.

Chemical control: during the overwintering period, spray trunks and branches with a diluted lime sulfur mixture at 3-5 degrees Baume. Flowers prone to chemical injury, such as cineraria, must not be treated with it; scatter sulfur powder on the ground, generally using 25-30 grams per 70 sq m, to eliminate overwintering sources of the fungus.

During the growing season, protective fungicides can be sprayed before disease onset, and systemic fungicides should preferably be sprayed after disease onset. According to the disease symptoms, the growth of flowers and trees, the climate conditions and the characteristics of the pesticide, apply the chemical once every 5-20 days, for 2-5 consecutive applications. For flowers and trees in one season, a single systemic fungicide may be applied only 1-2 times; the types of pesticide should be changed frequently to avoid the pathogen developing resistance.

Commonly used protective fungicides include: 50% sulfur suspension concentrate at 500-800 times dilution, 45% lime sulfur mixture crystals at 300 times dilution, 50% thiram wettable powder at 800 times dilution, 75% chlorothalonil at 500 times dilution, and 70% mancozeb at 400 times dilution.

Systemic fungicides include: 50% carbendazim at 500 times dilution and 75% thiophanate-methyl at 1000 times dilution. When the disease is rampant, 15% triadimefon at 1000 times dilution can be sprayed.

Antibiotic types include: 2% antimycin aqueous solution at 200 times dilution and 10% polyoxin (Baolian) at 1000-1500 times dilution.

Other agents also include baking soda at 500 times dilution, which can be sprayed once every 3 days in the early stage of disease onset, for 3-6 consecutive sprays. In addition, baijiu (35% alcohol content) at 1000 times dilution can be used, sprayed once every 3-6 days, for 3-6 consecutive sprays, washing the leaves until there is no white powder left.

For flowers and trees planted in protected areas such as greenhouses and conservatories, in addition to spraying the various chemicals above, fumigants and dust formulations can also be applied. Before planting or after finishing, empty-greenhouse disinfection should be carried out: for every 100 sq m, use 250 grams of sulfur powder and 500 grams of wood shavings, mix evenly, divide into 10 piles, and ignite with red-hot coal balls or charcoal; do not use an open flame, and keep the greenhouse closed for one day and night. During fumigation, strictly guard against fire. Fumigation during the growing period of flowers and trees easily causes chemical injury and should be used with caution. During the plant growing period, before disease onset, use 45% chlorothalonil smoke formulation at 25 grams per 67 sq m, or spray 5% chlorothalonil dust formulation at 100 grams per 67 sq m