Seed Dressing Maize with Imazapyr to Control Striga Hermonthica in Farmers' Fields in the Savannas of Nigeria.

Seed Dressing Maize with Imazapyr to Control Striga hermonthica in Farmers' Fields in the Savannas of Nigeria

ABSTRACT

Use small dose of imazapyr and pyrithiobac for seed coatings offers an effective means to control Striga. Field trials were conducted in Bauchi and Kano States of Nigeria in 2014 and 2015 under heavy Striga infestation to evaluate the potential effectiveness of herbicide coated hybrids maize on Striga control in farmers' field.  Results showed that herbicide coated seeds reduced number of emerged Striga per m² and Striga damage symptoms in farmers' fields in all the locations. Herbicide seed coating did not significantly increase grain yields of each hybrid. Also, the OPV checks produced grain yields that were not significantly different from those of the untreated hybrids.   The result revealed that coating of IR hybrid maize seeds with imazapyr was effective in reducing Striga infestation in farmers' fields. There was however, no yield advantage of herbicide-coated seeds over the untreated seeds of the hybrid that were bred for tolerance to Striga infestation. Although herbicide seed coating did not give yield advantages of the hybrids over the untreated checks, a combination of herbicide seed treatment and genetic resistance to Striga would serve as an effective integrated approach that could significantly reduce the parasite seed bank from the soil and prevent production of new seeds. The IR-hybrids and the OPV checks contained Striga resistance/tolerant genes that protected them against drastic yield loss in the Striga infested fields in both Bauchi and Kano.

Key Words: Maize, Striga hermonthica, Imazapyr seed coating