Agronomic evaluation of silage sorghum genotypes in a Hidromorfic Planosol at the Southern Coast of the Rio Grande do Sul State, Brazil, in 2010 / 2011

Abstract

This work was conducted to quantify the forage production and the partitioning of the dry matter of 21 ge- notypes and four cultivate of sorghum for silage, cultivated in a Hidromorfic Planosol in the South of Rio Grande do Sul State, Brazil. The experimental design was a randomized block design with three replications and the 25 genotypes were evaluated for 12 agronomic traits. The variance analysis showed significant difference among the treatments for all the evaluated traits, except the dry matter production. The results showed an average green matter production of 38.710 kg ha–1, average dry matter production of 13.286 kg ha–1 and average leaf dry matter production of 2.530 kg ha–1. The mean percentage of leaves, stems and panicles was: 20, 38 and 42 %, respectively. The mean dry matter content was of 34 %, varying from 26 to 41 %. The distance analysis divided the genotypes in two groups. Genotypes of longer cycle produced more percentage of panicles in dry matter, except the check Volumax, and higher dry matter content, while the genotypes with shorter cycle presented larger percentages of leaves and stems, green matter production and production of leaf dry matter production.