Orchid tip burn and tip shrinkage can be roughly divided into four types

1. The inside of the pot is too dry, or the air humidity is too low and the pot surface is too dry. In this case, orchid leaf tip shrinkage generally cannot be shown immediately. The first reflection is that the orchid leaves appear dehydrated. After watering restores them, the decline easily starts from the old seedlings, and the orchid leaves turn yellow from the top downward. If there is water damage inside the pot, the orchid leaves turn yellow from the bottom upward, and the decline is slower;
2. Fungal damage to orchid roots or waterlogging of the root crystal tips should be the same in principle. Waterlogging is the process, crystal tip rot is the result, and tip burn is the surface phenomenon. For this kind of tip burn, as Feixiang said, the leaf tips turn black. After the pot is treated, the tip burn generally no longer extends downward;
3. Tip burn caused by fertilizer damage: the burned tip is brown or black, with a very obvious boundary between it and the parts of the orchid leaf not affected by fertilizer damage, and spots from fertilizer damage also easily appear on the normal tissues of orchid leaves. Such irregular round spots have a brown center, and where they contact normal tissue there is a ring of black spots of uneven thickness, with a very obvious boundary as well;
4. When orchid plants develop fungal damage, much of it is shown through the phenomenon of tip burn. For example, with tip blight, the burned tip is white-brown, and the junction with normal orchid leaf tissue is black-brown. The white-brown is the dead, withered area, and the black-brown is the area where the fungal damage is active. With leaf blight, the pale brown at the leaf tip is the dead, withered area, and the black-brown is the area where the fungal damage is active. Where it contacts normal orchid leaf tissue, it mostly appears yellow-green, and this yellow-green area is the infected area of normal orchid leaf tissue, which is different from tip blight. Anthracnose also easily shows tip burn: the leaf tip appears in one section black-brown and one section pale brown, alternately developing toward the lower part of the orchid leaf, and independent or connected black-brown patches also appear in the leaf blade, with the outer edges of the patches appearing pale yellow.