How to prevent and control gray mold in flowers? Detailed explanation of prevention and control methods for greenhouses
Do not assume that flowers grown in greenhouses are safer and rarely suffer from diseases. In fact, gray mold is one of the important diseases of greenhouse flowers, and it is very harmful to the flowers, fruits and leaves of ornamental plants. The editor will introduce to you the prevention and control methods for gray mold in greenhouse flowers.
Greenhouse flowers
1. Seed disinfection: To kill the fungi attached to the surface of flower seeds, the seeds can be soaked in a 10% trisodium phosphate solution for 20 minutes, rinsed under running water for 40 minutes, and then used. They can also be soaked in warm water at 52°C for 30 minutes, then dried and set aside for later use.
2. Soil replacement planting: The pathogen mainly overwinters in the soil. Therefore, whether for garden planting or pot planting, the soil must be disease-free new soil, and the potting soil, flower pots and bulbs must be disinfected.
3. Reasonable fertilization: Apply fully decomposed organic fertilizer as much as possible, increase the application of phosphorus and potassium fertilizers to improve the disease resistance of the plants, and at the same time pay attention to controlling the amount of nitrogen fertilizer to prevent excessive vegetative growth and worsen the disease.
4. Greenhouse management: Remove diseased leaves, diseased flowers and fruits, and yellow leaves in time, keep the greenhouse clean, and ensure good ventilation and light transmission. High-temperature sealed greenhouse treatment can inhibit bacteria. In the early growth stage and after the onset of disease, appropriately control watering and ventilate later at the proper time. Raise the greenhouse temperature to 33°C, as this is unfavorable for the production and differentiation of spores. Reduce humidity to decrease condensation on the greenhouse roof and leaf surfaces.
5. Chemical control: In the early stage of disease onset, 45% chlorothalonil smoke agent can be used, or 15% procymidone can be used for fumigation for 3 to 4 hours. In the early stage of disease onset, spray 50% procymidone 1000-fold solution, or 50% duomeiling 1000-fold solution, alternating use every 7 days, for 2 to 3 consecutive applications, all of which can effectively control the occurrence of gray mold.
Prevention and control methods for gray mold in greenhouse flowers
China Landscape Web, November 20 news: Gray mold is an important disease of greenhouse flowers, mainly harming the flowers, fruits and leaves of ornamental plants. It often occurs along with the flower growing season, especially during winter and spring greenhouse growth periods. If management is neglected, it is even more conducive to the occurrence and spread of the disease. In severe cases, it can cause a large number of flowers and leaves to drop, affect plant flowering, and reduce ornamental value.
Pathogen and conditions for occurrence: Gray mold is caused by Botrytis cinerea of the Deuteromycotina. The pathogen overwinters as mycelium or conidia and sclerotia attached to diseased plant residues, or left in the soil. The suitable temperature for the development of this fungus is 10°C to 32°C, with a minimum of 4°C, and the relative humidity is required to remain above 90%. Because the spring temperature is suitable and the humidity in the greenhouse is high, failure to ventilate in time is the main reason for the relatively severe occurrence of the disease.
Main symptoms of the disease: The pathogen invades through the stomata or wounds of the calyx hairs and flower stalks, spreads to the fruit stalks, and the fruit skin becomes grayish-white, water-soaked and soft-rotted. When humidity is high, a large amount of gray mold layer is produced on the fruit surface. Diseased flowers falling onto the leaf surface can easily cause leaf disease, forming large round spots bearing gray mold. Rotten flowers and rotten fruits falling onto the stems cause stem rot, and in severe cases the plants wither and die. For example, when chrysanthemum leaves are affected, the leaf edges show brown spots, the surface is slightly wavy with concentric rings, the petioles and flower stalks soften first, and then the exterior rots. When fuchsia leaves are affected, the diseased leaves show water-soaked spots that gradually turn dark brown and rot. In addition, gerbera and cyclamen are also susceptible to damage.
Prevention and control methods:
1. Seed disinfection: To kill the fungi attached to the surface of flower seeds, the seeds can be soaked in a 10% trisodium phosphate solution for 20 minutes, rinsed under running water for 40 minutes, and then used. They can also be soaked in warm water at 52°C for 30 minutes, then dried and set aside for later use.
2. Soil replacement planting: The pathogen mainly overwinters in the soil. Therefore, whether for garden planting or pot planting, the soil must be disease-free new soil, and the potting soil, flower pots and bulbs must be disinfected.
3. Reasonable fertilization: Apply fully decomposed organic fertilizer as much as possible, increase the application of phosphorus and potassium fertilizers to improve the disease resistance of the plants, and at the same time pay attention to controlling the amount of nitrogen fertilizer to prevent excessive vegetative growth and worsen the disease.
4. Greenhouse management: Remove diseased leaves, diseased flowers and fruits, and yellow leaves in time, keep the greenhouse clean, and ensure good ventilation and light transmission. High-temperature sealed greenhouse treatment can inhibit bacteria. In the early growth stage and after the onset of disease, appropriately control watering and ventilate later at the proper time. Raise the greenhouse temperature to 33°C, as this is unfavorable for the production and differentiation of spores. Reduce humidity to decrease condensation on the greenhouse roof and leaf surfaces.
5. Chemical control: In the early stage of disease onset, 45% chlorothalonil smoke agent can be used, or 15% procymidone can be used for fumigation for 3 to 4 hours. In the early stage of disease onset, spray 50% procymidone 1000 -fold solution, or 50% duomeiling 1000 -fold solution, alternating use every 7 days, for 2 to 3 consecutive applications, all of which can effectively control the occurrence of gray mold.
Key points for preventing and controlling gray mold in greenhouse flowers
Gray mold is an important disease of greenhouse flowers, mainly harming the flowers, fruits and leaves of ornamental plants. It often occurs along with the flower growing season, especially during winter and spring greenhouse growth periods. If management is neglected, it is even more conducive to the occurrence and spread of the disease. In severe cases, it can cause a large number of flowers and leaves to drop, affect plant flowering, and reduce ornamental value. Pathogen and conditions for occurrence: Gray mold is caused by Botrytis cinerea of the Deuteromycotina. The pathogen overwinters as mycelium or conidia and sclerotia attached to diseased plant residues, or left in the soil. The suitable temperature for the development of this fungus is 10°C to 32°C, with a minimum of 4°C, and the relative humidity is required to remain above 90%. Because the spring temperature is suitable and the humidity in the greenhouse is high, failure to ventilate in time is the main reason for the relatively severe occurrence of the disease. Main symptoms of the disease: The pathogen invades through the stomata or wounds of the calyx hairs and flower stalks, spreads to the fruit stalks, and the fruit skin becomes grayish-white, water-soaked and soft-rotted. When humidity is high, a large amount of gray mold layer is produced on the fruit surface. Diseased flowers falling onto the leaf surface can easily cause leaf disease, forming large round spots bearing gray mold. Rotten flowers and rotten fruits falling onto the stems cause stem rot, and in severe cases the plants wither and die. For example, when chrysanthemum leaves are affected, the leaf edges show brown spots, the surface is slightly wavy with concentric rings, the petioles and flower stalks soften first, and then the exterior rots. When fuchsia leaves are affected, the diseased leaves show water-soaked spots that gradually turn dark brown and rot. In addition, gerbera and cyclamen are also susceptible to damage.Prevention and control methods
1. Seed disinfection. To kill the fungi attached to the surface of flower seeds, the seeds can be soaked in a 10% trisodium phosphate solution for 20 minutes, rinsed under running water for 40 minutes, and then used. They can also be soaked in warm water at 52°C for 30 minutes, then dried and set aside for later use.
2. Soil replacement planting. The pathogen mainly overwinters in the soil. Therefore, whether for garden planting or pot planting, the soil must be disease-free new soil, and the potting soil, flower pots and bulbs must be disinfected.
3. Greenhouse management. Remove diseased leaves, diseased flowers and fruits, and yellow leaves in time, keep the greenhouse clean, and ensure good ventilation and light transmission. High-temperature sealed greenhouse treatment can inhibit bacteria. In the early growth stage and after the onset of disease, appropriately control watering and ventilate later at the proper time. Raise the greenhouse temperature to 33°C, as this is unfavorable for the production and differentiation of spores. Reduce humidity to decrease condensation on the greenhouse roof and leaf surfaces.
4. Chemical control. In the early stage of disease onset, 45% chlorothalonil smoke agent can be used, or 15% procymidone can be used for fumigation for 3 to 4 hours (250 grams per mu of greenhouse). A 5% chlorothalonil dust agent (1 kilogram per mu of greenhouse) can also be sprayed in the evening. For the spray method, a 65% zineb wettable powder 500-fold solution can be used, sprayed once every 10 days, for 2 to 4 consecutive sprays (interval period 7 to 10 days). In the early stage of disease onset, spray 50% procymidone 1000-fold solution, or 50% duomeiling 1000-fold solution, alternating use every 7 days, for 2 to 3 consecutive applications, all of which can effectively control the occurrence of gray mold.
5. Reasonable fertilization. Apply fully decomposed organic fertilizer as much as possible, increase the application of phosphorus and potassium fertilizers to improve the disease resistance of the plants, and at the same time pay attention to controlling the amount of nitrogen fertilizer to prevent excessive vegetative growth and worsen the disease.