Prevention and Control of Orchid Bacterial Soft Rot Disease
Sharing with you the content of orchid cultivation in the flower clinic, focusing on the prevention and control of orchid bacterial soft rot disease. Detailed information will be shared next.
The main pathogen of bacterial soft rot disease is Erwinia carotovora: the disease peaks during the rainy season when new buds emerge. Infected tender leaves show brown, water-soaked spots at the base, which quickly expand and merge into patches, affecting the leaf sheaths and the growing points of the buds. Maturing leaves are also often infected, endangering pseudobulbs. Infected leaves rot at the base, emitting a foul odor, and the upper part shows dehydration-like wrinkles.
This bacterium can harm all species of national orchids, as well as Cattleya, Oncidium, Aerides, Phalaenopsis, Vanda, etc., with severe outbreaks in southern China. It mainly affects orchid leaves and pseudobulbs. Initially, infected leaves show small, water-soaked spots that gradually turn brown or nearly black and quickly expand, eventually developing into a soft, foul-smelling rot with secretions, which can spread through rainwater or irrigation. If pseudobulbs are infected, they will also show water-soaked spots, turning brown to black, eventually becoming soft, shriveled, and dark, rotting rapidly.
Bacterial soft rot disease often occurs during the early summer rainy season, spreading through wounds, breaks, or insect bites. The disease is particularly severe in high temperatures, excessive rain, or poor ventilation, and can cause entire leaves to rot within 3-5 days, being fatal whether on old or new leaves. Preventing bacterial soft rot disease requires maintaining a well-drained and ventilated cultivation environment with plenty of sunlight. Diseased spots should be immediately removed and destroyed. If the spots reach the growing point, the entire plant should be isolated in its pot, and avoid spraying water, instead using overhead irrigation.
After removing the diseased tissue, the affected leaves should be cut promptly, the wounds treated with Bordeaux mixture, and the orchid soaked in a 0.1% potassium permanganate solution for 5 minutes. After rinsing with running water, the plant should be dried in the sun for 15 minutes before planting. Spraying with 0.5% Bordeaux mixture or 200mg/L agricultural streptomycin or methylthiophosphate can also be effective. Alternatively, regularly spraying 30.3% tetracycline at 2000 times dilution, or 10% streptomycin at 1000 times dilution, or 68.8% polyoxin at 1000 times dilution can also provide significant preventive and therapeutic effects.
At the same time, I hope that orchid friends affected by "bacterial soft rot disease" can soon be free from this "misery."
The above-mentioned information on the prevention and control of orchid bacterial soft rot disease (practice) is provided for your comprehensive understanding and reference!