The effect of spore suspensions and culture filtrates of five Trichoderma spp. on
controlling reniform nematode, RotyJenchuJus reniformis and wilt fungus, Fusarium
oxysporum, disease complex, and also on growth of sunflower plants was studied in
vitro and under greenhouse conditions. Two weeks old sunflower seedlings 01. Giza 1
treated with each of spore suspension or culture filtrate of Trichoderma harzianum, T.
vi ride , T. koningii, T. reese! or T. hamatum had highly significant effect on controlling
nematodes infection and disease incidence on sunflower roots. T. hamatum, T.
harzianum and T. koningii culture filtrates gave a highly significant reduction (P in vitro and decreased the population of female nematodes on sunflower roots. The
same results were observed when pots were treated with spore suspension of
Trichoderma species alone, or in combination with F. oxysporum. Sunflower plants grown in infested soil with F. oxysporum and R. reniformis mix inoculum showed severe wilt disease than in soil infested with F. oxysporum alone . Treatment of Trichoderma spp. led to inhibit Fusarium growth in vitro and also in infested soil with R. renlformis and improved significantly the plant growth parameters. Use of T. hamatum, T. harzianum and T. koningii gave the greatest reduction of disease incidence caused by Fusarium and/or R. reniformis infestation. Generally, there were highly significant reduction (PTrichoderma species. It can be summarized that the role of Trichoderma spp. in controlling of R. reniformis and F. oxysporum as direct effect by toxic metableolites