Morphological factors conferring resistance in spring maize to shoot fly, Atherigona soccata (Rondani)

Various plant mechanisms and physico-morphological factors contribute to resistance against herbivores. To identify the morphological characters responsible for resistance in spring maize to shoot fly, Atherigona soccata (Rondani), four maize genotypes including, two hybrids; 193-2x161 (resistant), 1128x163 (susceptible) and two inbred; C-78 (resistant) 1348-6-2 (susceptible) were examined. It is concluded that seedling height, number of leaves per plant and leaf length was more in hybrid genotypes as compared to inbred lines and also in resistant genotypes. While, leaf width was observed significantly less in hybrid lines as compared to inbred genotypes and also in resistant genotypes. Mean seedling height, number of leaves per plant and leaf length was observed maximum (28.82 cm, 9.22 and 21.85 cm, respectively) on resistant hybrid 193-2x161, whereas maximum mean leaf width (1.64 cm) was observed in susceptible hybrid 1128×163. Similarly, mean seedling height, number of leaves per plant and leaf length was observed maximum (19.77 cm, 5.78 and 17.72 cm, respectively) in resistant inbred C-78 whereas, mean leaf width was observed maximum (2.35 cm) in susceptible inbred 1348-6-2. Regardless of genotypes, the seedling height, number of leaves per plant, leaf length and leaf width did not differ significantly between different dates of sowing. During different date of sowing i.e. 1^st (20^th February), 2^nd (7^th March) and 3^rd sowing (22^nd March) more seedling height, leaf length, number of leaves per plant and less leaf width was recorded in resistant genotypes.