due to high antagonistic activity of trichoderma harizanum, 5 isolates t.h.k, t.h.bi, t.h.mo, var33 and torbat vi were selected and their efficacy was studied for controlling sugar beet damping-off caused by rhizoctonia solani, under in vitro and in vivo conditions. antagonistic ability of t. harzianum isolates was investigated as dual culture on pda in concomitant and sequential cultures, 48 ...