Various propagation and care process for Haworthias can leave wounds on the plant bodies. A proper management not only protects a plant from rotting caused by pathogen infection but also promotes faster growth of plant tissues like roots.
Thiophanate-methyl is an effective fungicide and has systemic effects. For treatment, use a cotton swab and mix a small amount of fungicide powder in ~70% isopropyl alcohol solution (rubbing alcohol). Alcohol can kill certain pathogens and assists fungicide to permeate plant tissues. Dip the wound into the solution, or use the cotton swab to spread the solution on the wound. After dry, the fungicide will form a very thin layer of coating on the wound. Keep the plant in a shaded and cool (ideally ∼20°C) place for 2~3 weeks, till callus has developed on the wound.