Corn genotypic variation effects on seedling emergence and leaf appearancefor short-season areas

Identifying corn (Zea mays L.) genotypes with faster rates of seedling emer gence and leaf appearance is important in developing a corn crop with earli er canopy closure and better seasonal light interception. A greenhouse expe riment was conducted twice to investigate whether corn genotypes known to v ary in canopy architecture and yield potential differed in rates of seedlin g emergence and leaf appearance. The experiment was arranged in a randomize d complete block design utilizing seven genotypes: five of the newly develo ped Leafy reduced-stature (LRS) types (LRS1, LRS2, LRS3, LRS4 and LRS5), on e conventional type [Pioneer 3979 (P3979)], and one late-maturing big-leaf (LMBL) type. Five seeds were planted in each pot and seedling emergence was recorded every day until all seeds emerged. Leaf appearance was recorded f rom seedling emergence until the plants reached anthesis. There was variabi lity among the genotypes for both seedling emergence and leaf appearance ra te. Mean seedling emergence values of greater than 90 % were achieved by fo ur of the five LRS genotypes, and the LRS types generally emerged more rapi dly than the others. Leaf appearance rate showed linear increases over time ; however, LRS genotypes (in particular LRS3, LRS4 and LRS5) had more rapid leaf appearance rates than the others. The LMBL hybrid ranked last for bot h seedling emergence (<80 %) and leaf appearance rate. Rapid seedling emerg ence and leaf appearance by early-maturing genotypes (LRS and P3979, especi ally LRS) may help these types of genotypes achieve earlier canopy closure and better use of the light available during the growing season, which is c ritical in a short growing season environment.