Differences Between Orchid Soft Rot and Stem Rot and Their Prevention and Treatment

Orchid'ssoft rotdisease and stem rot differences and prevention and treatment

In recent years, due to climate change and the rapid cultivation of orchid seedlings with hormones under high temperature and high humidity, the difficulty ofgrowing orchidshas increased. Orchid enthusiasts without certain facility conditions have in the past two yearshad manyorchids die from soft rot and stem rot, with great losses. In order to let everyone understand these two biggest killers of orchids, I have summarized the experience of various orchid friends on the Chinese Orchid Network and some of my own understanding as follows:

Soft rot: The symptoms start from the new shoots first. The characteristic is that the plant's base turns black and soft from the inside out, with a foul odor and soft rot of the pseudobulbs. It is an acute disease.
Stem rot: The symptoms start from the parent generation or the generation before that first. The characteristic is that the plant's base gradually turns yellow and withers from the outside in, and the pseudobulbs turn yellow and hard, like a chronic disease.

Soft rot is a bacterial soft rot disease

Protective fungicides: These fungicides can protect the treated areas not yet infected by pathogens from infection. They need to be sprayed before the crop comes into contact with the disease or before the disease occurs to be effective, such as copper formulations (Bordeaux mixture), sulfur formulations (lime sulfur), mancozeb, etc.

Eradicant fungicides: These agents can directly kill pathogens before invasion and treat already infected treated areas, and often have a disinfecting effect. For example, using formalin to disinfect infected seeds.

Therapeutic fungicides: Also called systemic fungicides. After being absorbed and translocated by the plant, these fungicides can stop the development of pathogens in various parts of the plant. Such as carbendazim, thiophanate, kasugamycin, etc.

Different types of fungicides have different methods of use; follow the instructions.

Stem rot belongs to a type of disease caused by fungal damage. Therefore, using some antifungal medications gives better results! Such as Amistar, metalaxyl-mancozeb, and some of the combined medications mentioned by the original poster.
Stem rot is caused by fungi; try Amistar, the results are quite good.
Whether it is soft rot or stem rot, there is no specific cure. The important thing is still prevention first. You can try 58% metalaxyl-mancozeb. Dilute 1 to 600 times to drench the roots and spray the leaves. Because metalaxyl-mancozeb both kills fungi and protects.

Once discovered, immediately separate the plants and be willing to discard them. Wrap the orchid seedlings that can already be seen to be infected in plastic bags and throw them into the trash bin. Then, according to the above methods, treat the dying as if they were alive!!