Relationship among Aspergillus flavus Infection, Maize Weevil Damage, and Ear Moisture Loss in Exotic × Adapted Maize

Abstract

Maize (Zea mays L.) kernel infection by Aspergillus flavus and infestation by maize weevil (Sitophilus zeamais Motschulsky) remain problems in maize production and storage. This study was undertaken to evaluate 61 exotic × adapted breeding crosses obtained from the Germplasm Enhancement of Maize (GEM) project for A. flavus kernel infection rates (KIR), resistance to maize weevil damage (MWR), and ear moisture loss rate (EMLR) in 1995 and 1996, and to investigate interrelationship among them via correlation and path analyses. Highly significant correlations among the three traits were detected. A direct path effect of MWR on KIR was −0.261 (P=phenotypic) and -0.42 (G=genotypic). The direct effect of KIR on MWR was −0.276 (P) and −0.623 (G). This suggested KIR would decrease when selection is practiced for higher levels of resistance to maize weevil feeding, and vice versa. Direct path coefficient for the EMLR effect on KIR was positive at both P (0.233) and G (0.50) levels. The direct effects of KIR on EMLR were 0.25 (P) and 0.67 (G). The positive association between KIR and EMLR would be unfavorable for simultaneous selection of both traits in the desired direction. The correlation and path analyses for KIR, MWR, and EMLR provided useful information about the traits, which could be used in simultaneous selection to maximize selection gains. The KIR and MWR appeared to be the traits that could be handled in a single breeding program. From an efficiency standpoint, improvement of EMLR should be handled in a separate breeding program.