Z Sadowsky, I Chet

When hyphae of the antagonist Trichoderma harzianum approach those of the pathogenic fungus Rhizoctonia solani, they form branches which grow directly towards the host. Fibrillar material is deposited between the hyphae during the first two days of interaction. Vapour fixation and air drying of specimens enabled visualization of the delicate structures, without washing soluble material from the system. T. harzianum also produces hyphal coils over the interaction zone.