Autumn Flower Disease Prevention
This article introduces some knowledge about the flower clinic, emphasizing the importance of preventing diseases in autumn flowers. Next, the site editor will introduce to the netizens.
After the beginning of autumn, moderate temperature and humidity, good lighting, create favorable conditions for the breeding and infection of some pathogens, often causing serious harm to certain flowers. Here are the symptoms and control methods of several common diseases:
Powdery mildew is most severe in flowers such as cucumis, roses, dahlias, wolfberries, Chinese rose, zinnias, large leaves, and yellow boxwood. The affected parts first show scattered white spots, then gradually expand and spread, and the development speed is very fast. Under suitable conditions, the lesion can cover the entire leaf within 7-10 days, with a white powdery substance on the leaf surface, as if it were frosted. In severe cases, the leaves wither and fall early. The plant loses its photosynthesis, resulting in fewer, smaller, and lighter-colored flowers, and some may not even bloom.
Prevention methods:
1. Enhance ventilation and lighting conditions; increase phosphorus and potassium fertilizers, avoid excessive nitrogen fertilization, avoid excessive watering, and do not let the potting soil accumulate water. It is also important to remove diseased leaves and buds and uproot diseased plants for incineration.
2. Chemical control. When the disease first appears, some flowers can be sprayed with a 1:1:140 Bordeaux mixture, or 25% triadimefon 1500 times liquid, 70% thiophanate-methyl 1200 times liquid, 50% validamycin 1500 times liquid. Alternating the use of these fungicides can enhance the control effect. When the disease is severe, spray again after 7 days, for a total of 2-3 times.
Brown spot disease mainly affects leaves. Initially, brown spots appear on the leaf surface, which gradually expand and merge into large spots. The lesions are usually irregular due to the restriction of leaf veins. There is a bleached halo around the spots, with red-brown edges and gray-white centers. Later, black spots (conidiomata) appear in the lesions. The affected leaves are prone to fall, and in severe cases, no leaves remain, leading to the gradual withering of the entire plant from the bottom up. Flowers such as azaleas, narcissus, jasmines, syringas, osmanthus, crabapple, photinia, and lotus are most affected.
Prevention methods:
1. Promptly prune diseased branches and leaves, and incinerate them to reduce the source of reinfection.
2. Chemical control. After the disease occurs, spray 80% captan 500 times liquid, 65% zineb 800 times liquid, 12.5% validamycin wettable powder 1000 times liquid, or 70% thiophanate-methyl 1200 times liquid every 7-10 days, for a total of 2-3 times.
Flower rot disease mainly affects flowers, flower buds, and fruits, and can also affect leaves. After the leaves are affected, brown spots appear, which gradually expand, causing a large amount of grayish-white moldy substance to form on the affected area. When flower buds first appear, they can rot and become brownish-yellow and withered. This disease occurs easily in conditions of abundant rainfall, high humidity, and frequent fog. It poses a significant threat to flowers such as dahlias, celosia, roses, crape myrtles, zinnias, Chinese roses, and fruit-bearing flowers like pomegranates.
Prevention methods:
1. During continuous rainy weather, take measures to prevent rain, especially to protect flower buds and flowers from rain. Strengthen cultivation management, apply phosphorus and potassium fertilizers, and prune reasonably to enhance ventilation and lighting.
2. Chemical control. Before the disease occurs, spray lime sulfur solution at a concentration of 3-5 degrees Baume, which can protect and prevent the disease. When the disease first appears, spray 5% tanaline solution 500 times, 50% validamycin wettable powder 1500 times, or 75% chlorothalonil 1000 times. When the disease is severe, spray every 7-10 days, for a total of 2-3 times.
The above provides a comprehensive introduction to autumn flower disease prevention, hoping to bring some knowledge about green plants to plant enthusiasts.