Formulation and field experiment of Fusarium oxysporum isolates for biocontrol of Orobanche aegypyiaca

To investigate the application of an isolate of Fusarium oxysporum for biocontrol of Egyptian broomrape (Orobanche aegyptiaca), the biological agent was formulated with Aluminum Silicate and white flour as wettable powder. Then, the efficacy of this biological product was investigated in 2008 at two Agricultural Research Stations in Varamin and Zanjan, and in 2009 only in Zangan. In experiments of first year, the methods of application of this product at 1x106 or 1x107 spores L-1 in water were studied. But, in the experiment of the second year, the efficacy of this product was compared with chemical herbicide sulfosulfuron. In Varamin experiment, the biological product used at 1x107 spores L-1 was significantly more effective in reducing number of stems, number of plants and dry weight of broomrape and enhancing of tomato fruit yield than that used at 1x106 spores L-1. In Zanjan experiment in 2008, submerging the roots of tomato in solution of biological product in water at 1x107 spores L-1, was more effective in reducing the number of broomrape plants than the other application methods. But, non of application methods, compared with control, had significant effect on dry weight of broomrape. In this experiment, just the putting the biological product at 1x107 spores L-1 in the soil around the tomato plants immediately after transplanting resulted to significant increase of crop yield. In Zanjan experiment in 2009, application of sulfosulfuron, compared with control, in most causes, significantly reduced number and dry weight of broomrape, but this chemical herbicide had no significant different with the biological control. In this experiment, only twice application of sulfosulfuron, each time 50 g ha-1, compared with control, significantly increased the crop yield. In all experiments, no wilting or phytotoxicity due to application of the biological product or the chemical herbicide was observed.