Productive performance and multivariate interrelations of open-pollinated and hybrid maize in Brazil
Corn is considered one of the most important crops in the world agricultural scenario. In order to improve production, it is crucial to understand and quantify the genetic variation involved in the phenotypic manifestation of this species. We evaluated the agronomic performance of open pollinated genotypes, used by small scale family farmers, compared to commercial hybrid genotypes in various growing environments. The experimental design was a randomized block and the treatments were arranged in four replicates. Eight maize genotypes were used: three open-pollinated varieties and five simple hybrids. The following characters were measured plant height, ear insertion height, stem diameter, ear length, number of seed rows of the ear, number of seeds per row of ear, thousand seed weight and seed yield. The best yields of seeds were obtained in Entre-Ijuís, RS. Seed yield varied according to the genotype and growing environment; in Pelotas, RS the highest yields were obtained with the HC2 and HC1 genotypes (9090 and 9002 kg.ha-1, respectively). Genotypes with a narrow genetic base express less variation in their responses to the environments, in contrasting environments. Under limiting conditions the open pollinated varieties responded favorably. The use of biometric approaches allows us to reveal patterns in the grouping of genotypes.