Screening for sources of resistance to the maize weevil on stored maize varieties obtained in the Gambia

Abstract

The maize weevil, Sitophilus zeamais, is a serious stored product pest of maize in the tropical and subtropical countries. This study evaluated commonly used maize varieties collected from the National Agricultural Research Institute against the maize weevil. Using the Dobie index of susceptibility, eleven maize varieties were screened for resistance to the maize weevil. The Varieties of TZEE-Y and JEKA were resistant to S. zeamais, while TZE-W was susceptible, and the mechanism of resistance was antibiosis. The resistant varieties had a relatively longer median development time (MDT) and fewer F1 progeny emergence. Protein (r = -0.60*) content correlated negatively and significantly with susceptibility index. The susceptibility index showed a negative and significant relationship to MDT (R2 = 0.89*) and a positive relationship to F1 progeny (R2 = 0.90*). An increase in F1 progeny indicates an increase in grain damage (R2 = 0.95) and weight loss (R2 = 0.72). The maize varieties TZEE-Y and JEKA were the most resistant to the maize weevil, making them  romising for control.