Different Kernel Colour Maize Vulnerability to Sitophilus zeamays Storage Insect Pest

Maize kernels with various colours possess nutritional and sometimes pest resistance benefits. A study was conducted in Morogoro, Tanzania, to investigate farmer's claim that he was planting some red kernelled maize, which is very rare in Tanzania because red kernels were resistant to storage insect pests. Dark red and typical red cobs were purchased from the farmer and planted and subsequently a storage experiment was conducted to test the farmer's hypothesis. The red, dark red, deep yellow, yellow, light yellow, orange and white kernels were put in polyethylene bags and infested with Sitophilus zeamais then stored under normal room conditions alongside an insecticide treated control sample. Vulnerability to the storage insect pest varied among the different colours. Orange kernels were least vulnerable; light yellow and red kernels also possessed some level of resistance while dark red kernels were most vulnerable. Colour based resistance observed, however, did not show expected linearity according to the concentration of kernel colour determining biochemicals: carotenoids and anthocyanins. It was therefore concluded that attributes other than colour were also responsible for the observed variability in resistance, either concurrently independently or interacting with the kernel colours. More study of the association of maize kernel characteristics and kernel colour with storage insect pest vulnerability in relation to genotypes of the crop seems to be worthwhile