Morphological plant factors affecting resistance to Atherigona spp. in maize

Abstract

Seven maize genotypes were evaluated against shoot fly species (Ather/gona soccata Rondani and A. naqvii Steyskal) under heavy natural infestation during spring, 1995 and 1996 seasons. The shoot fly species did not discriminate amongst the plants of different varieties while laying eggs in the field. All the varieties differed significantly from each other in relation to dead-heart formation due to shoot flies, the lowest being in Antigua Gr. I and highest in eM - 300. Significantly more number of dead-hearts were formed in 1996 than 1995. Morphological plant characters were either positively or negatively correlated with the number of eggs laid by shoot fly species showing insignificant differences indicating that these did not influence the egg laying by shoot flies in the field. The leaf width and stem thickness, number of leaves/plant and leaf length were positively and negatively, respectively significantly correlated with dead-heart percentages. It showed that resistant varieties had less stem thickness and leaf width, more leaf length and number of leaves/plant as compared to susceptible ones. However, other plant characteristics were either negatively or positively correlated showing non-significant difference.