**2. Materials and methods**

Thirty-six genetic materials were used for the study and this included 19 exotic inbred lines developed for aflatoxin accumulation resistance by the corn host resistance plant unit (CHPPRU) in Mississippi, USA and seventeen locally adapted genotypes. Pedigree information on germplasm is presented in **Table 1**.

#### **2.1 Field experimental sites and layout**

Three locations were used for the experiments, namely Fumesua, Akomadan, and Wenchi. Fumesua is in the semi- deciduous forest zone with an altitude of 286 m above sea level and it lies within 6.712 N and 1.523 W. The mean annual rainfall is 1500 mm coupled with mean minimum and maximum temperatures of


**Table 1.** *List of germplasm and pedigree.* 21°C and 31°C, respectively. Soils around Fumesua are classified as Asuansi series, a ferric acrisol. Akomadan is situated within the forest savanna transition zone and it lies within 7.396 N and 1.973 W. It has a bimodal rainfall distribution pattern same as Fumesua. Wenchi on the other hand lies within 7.733 N and 2.100 W, a transitional savanna zone with bimodal rainfall pattern similar to the other two locations.

For the three locations, major season begins in March and usually ends in July whilst the minor season begins from September and ends in November. The experiments were conducted during the major season of 2017 and minor season of 2017/2018 in all three locations for genotype evaluation. Plantings were staggered at weekly interval between sites. Experimental design used was a 6 x 6, square - lattice with three replications. Single row plots, each 5 m long, spaced 0.70 m apart with 0.4 m spacing between plants in each row were used in all the environments. Three seeds of the lines were planted in each hole and thinned to two plants per hill at two weeks after emergence to give a population density of 66,667 plants per hectare. Weeds were controlled through the use of Atrazine and Gramozone as pre- and post- emergence herbicides at 5 liters/ha each of Primextra and praraquat and subsequently supported by manual weeding.
