cactus disease dry root rot and rust plant caused by fungi, half cut fungi infected melocactus

anthracnose argriculture background botanic botanical botany cactaceae cacti cactus canker collection color corky cultivation cutting decease decoration decorative desert disease dry environment flora fungi garden globular grafting green grow growth gymno gymnocalycium hobby house isolated natural nature plant pot propagation root rot rust scab scion sharp small spike stem thorn tree white