Abstract:
Varying damage levels occur in maize during threshing. An experiment was conducted to
establish maize threshing-caused damage to kernels and subsequent seeds’ susceptibility to
storage insects. Kernels threshed by: machine, beating with stick, or pressing with fingers were
assessed for broken kernels, physiological performance with storage time, and hosting of
Sitophilus zeamais storage pest. Mechanical threshing or beating with stick both caused kernel
breakage. Beating with stick caused less damage than mechanized threshing in number of broken
kernel pieces and broken whole kernels (P<0.01). Seeds stored for two months and beyonds’
germination capacities were lower (P<0.05) in machine-threshed than in seeds threshed by
fingers. The physiological influence during storage was partly due to storage insect pests rather
than threshing caused damage alone. After 2 and 3 months, number of S. zeamais in mechanized
threshing was statistically larger than in fingers threshed grains. Percent normal seedlings was
low in all threshing methods insecticide-untreated samples at two months of storage;
significantly lower than percentages for treated samples. Mean germination time was
significantly positively correlated with number of broken kernel pieces and the number of
storage insect counted in the samples; which means the two kernel damage attributes suppressed
seed vigour. |
