The plum rain season is a high-incidence period for Southern blight in orchids; prevention comes first

A fellow orchid grower asked Haoshe Nongfu, what should be done when an orchid gets Southern blight? To be honest, Haoshe Nongfu has never encountered this orchid disease, so I asked a few of my senior orchid-growing friends to discuss this topic, and some of their experience may help you understand this disease.

Southern blight is a symptom caused by a fungal infection. It invades through the roots, stems, leaves and young shoots. Its appearance is white, silky-thread-like material, along with particles the size of rapeseeds. An infected orchid first develops soft rot at the roots that turns into yellow pus, and ultimately causes the roots, stems and leaves to rot together.

Southern blight is most easily contracted during the plum rain season, because its infection requires two conditions: high temperature and high humidity, and the plum rain season undoubtedly meets both conditions best. At present there is still no most effective method for dealing with Southern blight; prevention is the main approach. During the plum rain season, pay attention to ventilation, draining excess moisture, avoiding direct sun exposure after rain, and frequently spraying fungicidal agents. Do not use a single type of agent; generally use a mixture of thiophanate-methyl and carbendazim.

Isolate orchid plants already infected with Southern blight as soon as possible, keeping them far from existing orchid plants to avoid spreading the fungus. For deeply infected orchid plants, you must bear the pain and discard them, disposing of the pot and soil together, and the place where the orchid pots were placed must also be disinfected.

Wild orchids are inherently not prone to disease, but once cultivated artificially, various human factors accelerate the generation and invasion of fungi. Therefore, you should still manage them carefully in normal times and prevent trouble before it occurs. When you find the situation can no longer be controlled, you must learn to make the painful choice and handle it promptly, so as to eliminate future trouble.