Potencial forrajero de poblaciones de maíz y relación entre atributos agronómicos con la calidad

Abstract

The purposes of this study were to identify maize populations with high forage quality and to determine associations between agronomic and forage quality variables. Five genetic groups made up by 19 populations and six commercial hybrids were evaluated at Pabellon, Ags., and Torreon, Coah., Mexico, in split plot tests with three replications each and densities of 80,000 and 75,000 plants ha-1 respectively. Dry matter production (TDM), forage nutritive quality and estimated milk production per hectare were assessed. A significant interaction (P<0.01), was detected for populations within groups x locations only for ear dry matter percentage (EDMP), neutral detergent fiber (NDF), and in vitro digestibility (IVD); whereas all variables, except acid detergent fiber (ADF) were significant for groups. Hybrids had the highest TDM and estimated milk production with 20.3 and 12.5 t ha-1 respectively; while the earliest populations derived from highland germplasm showed the highest nutritive value with 49.7, 26.4 and 72.4 % of NDF, ADF and IVD respectively. The top populations for forage production and quality within groups were Pop 800, Lucio Blanco, Pop42 ETO IL, CPAB3, P3066WF2, A7597F2 and the hybrids Pantera and AS900. Days to harvest, NDF and ADF content, were the variables which showed stronger correlation (P<0.01) to IVD with coefficients of -0.74, -0.74 and -0.81 respectively; while TDM, EDMP and NDF showed more correlation to estimated milk production, with coefficients of 0.78, 0.84 and 0.55, respectively.