HARVEST STAGES, FORAGE YIELD AND QUALITY OF CORN HYBRIDS WITH DIFFERENT BIOLOGICAL CYCLE

Abstract

In México, the time for harvest of corn forage is traditionally made at the milking-dough or dough grain stages, and grain represents a low proportion of the forage; as a result, corn forage production and quality are generally low. The objective of the this study was to evaluate seversal milking line advances in order to define optimal the time for harvest, regarding the forage production and quality of two corn hybrids differing in biological cycle, with hybrids ‘Halcón’ (early) y ‘302PW’ (intermediate). The experiment was conducted, in Aguascalientes, México. Harvest stages were: dough, 1/3, 1/2 and 2/3 of the milk line advance. The experiment was a randomized complete block design with four replications in a split-plot arrangement in which plots corresponded to hybrids and harvest stages to split plots. The hybrid x harvest stage interaction was significant (P ≤ 0.05) only for dry matter percentage at harvest. The intermediate hybrid produced 6.6 t ha^-1 more dry matter and 2940 kg ha^-1 of milk than the early hybrid (P ≤ 0.05). As maturity advanced from dough to 2/3 milk line, dry matter increased in 4.7 t ha^-1, ear proportion in 17.5 %, milk production in 168 kg t^-1 and milk production per hectare in 6030 kg. The neutral detergent fiber diminished in 6.9 units and the acid detergent fiber in 3.6 units. Dry matter digestibility did not change and the average was 66.6 %. The results indicate that harvesting between 1/2 and 2/3 milk line is better than to harvest at dough stage, because yield and nutritional value increase significantly.