Ear-fill effects on yield and quality of silage corn

Abstract

The relationship between yield and forage quality of corn (Zea mays L.) is influenced by maturity and strength of reproductive sink. Our objective was to isolate the effect of ear fill alone on stover and whole-plant quality. Three hybrids (Pioneer Brand 3394, 3417, and 3504) were evaluated in Wisconsin during 1992 and 1993. Developing ear shoots were covered, partially covered, or left uncovered before pollen shed to create three levels of ear fill: 0, 50, and 100%. Whole-plant and stover samples were collected from plants harvested at approximately 300 g kg-1 dry matter concentration and evaluated for dry matter yield, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), and in vitro true digestibility (IVTD). As ear fill increased from 0 to 100%, whole-plant CP decreased by 10 g kg-1, NDF decreased by 86 g kg-1, ADF decreased by 42 g kg-1, ADL decreased by 1 g kg-1, and IVTD increased by 37 g kg-1. For stover, CP decreased by 18 g kg-1, NDF increased by 136 g kg-1, ADF increased by 94 g kg-1, ADL increased by 6 g kg-1, and IVTD decreased by 55 g kg-1. Digestibility of stover NDF increased by 15 g kg-1. An effective ear was clearly necessary to realize maximum total dry matter yield and quality.