How to Prevent and Treat Southern Blight in Orchids? A Full Analysis of Practical Methods

Orchid southern blight is caused by fungi of the subphylum Deuteromycotina. Infection begins in April to May, with the peak incidence period from June to August. The disease develops rapidly, causing the affected orchid plants to rot, wither and die. The control measures are as follows:

　　

1. Planting: New soil free of pathogens should be selected for planting orchids. When using old soil, it must be disinfected with formaldehyde solution; mix 1\10 wood ash plus New High Lipid Film into the soil to prevent the soil from becoming acidic. Select high-quality varieties. After planting, spray the soil surface with New High Lipid Film, which can preserve moisture, prevent water evaporation, protect against sun and drought, prevent soil compaction, suffocate and isolate sources of disease and pests, and protect seedlings so they grow vigorously.

　　

2. Management: Maintain a growing environment with good ventilation and light, and provide shading in summer and autumn. Pay attention to reasonable watering and fertilizing, and spray New High Lipid Film to preserve moisture and fertilizer. Prune dry and dead branches, diseased and weak branches, crossing branches and overly dense branches at the right time, and thin out excess flower buds. Apply Callus Antiseptic Film to pruning wounds to protect the growth of wound healing tissue and prevent infection by rot pathogens. Spray Flower Strengthening Pedicel Agent on flower buds, which can make the buds strong, the petals large, the flower color vivid, the fragrance rich and the flowering period longer.

　　

3. Chemical control: In seasons with frequent disease, an appropriate amount of 70% thiophanate-methyl wettable powder (or 75% chlorothalonil wettable powder) plus New High Lipid Film can be sprayed on the pot surface or leaf bases, once every 1 week, for 2-3 consecutive times for better results.