Submitted to: National American Phytopathology Meetings
Publication Type: Abstract Only
Publication Acceptance Date: April 13, 1997
Publication Date: N/A
Technical Abstract: The effect of different soil types and temperature regimes on biocontrol of Fusarium wilt of tomato by selected nonpathogenic isolates of Fusarium spp. was evaluated in greenhouse and growth chamber experiments. In addition, efficacy of biocontrol was evaluated against different isolates and races of the pathogen. Isolates of F. oxysporum (CS20, CS24) and F. solani (CS1), previously shown to reduce Fusarium wilt diseases of various crops, were applied to tomato seedlings in soilless potting mix and seedlings were transplanted into pathogen-infested field soil. Isolate CS20 effectively reduced wilt (52-81% disease reduction) in all four field soils tested, including two sandy loams, a loamy sand, and a heavy clay soil, whereas isolate CS1 was effective in all but the clay soil. Isolate CS20 was also effective in reducing disease (58-75%) under a variety of different temperature regimes, ranging from cool to hot temperatures (22-16, 28-22, and 32-26 C day-night temperature cycles). All isolates tested significantly reduced disease (48-66%) against multiple isolates of all three known races of the pathogen (1,2, and 3).