Use of Fusarium oxysporum for the control of Striga hermonthica in maize (Zea mays L.)

Objective: To evaluate the efficacy of a granular mycoherbicide formulation of Fusarium sp. for the control of Striga hermonthica in maize under a field condition. Methodology and results: Two maize varieties (Across 97 TZL and a farmer’s local) and four treatments (Fusarium oxysporum followed by 2,4 – D, F. oxysporum fb supplementary hoe weeding (SHW), F. oxysporum fb Triclopyr and a control (hoe weeded at 3 and 6 weeks after sowing) were laid out in a split – plot design with three (3) replications; assigning varieties to the main – plots and weed control treatments to the sub – plots. This trial was carried out in two locations (Makurdi and Lafia). Generally, number of plants infected with Striga and shoot count was highest in Makurdi than Lafia. Variety Across 97 TZL had significantly lower/fewer number of plants infected at 9 and 12 Weeks after sowing (WAS) and also delayed the emergence of Striga to 49 days after sowing (DAS), while the farmers’ local initiated early emergence at 36 DAS. Among the Striga control treatments, F. oxysporum either fb post emergence (POE) 2, 4 – D or Triclopyr at the rate of 0.36kg a.i/ha each resulted in significantly fewer plants infested by the parasitic plant and consequently higher grain yields than those fb by SHW or hoe weeded check. Conclusions and application of findings: The study results demonstrate the high potentiality of using F. oxysporum (mycoherbicide) for the control of S. hermonthica by spot application at sowing and thereafter followed by either 2, 4 –D or Triclopyr POE at 6 WAS. The use of maize grits which is readily available to propagate F. oxysporum makes it quite cheap for local farmers instead of the use of potato dextrose agar.