Forage Quality Response of Four Lovegrasses to Stage, Interval, and Season of Harvest1
- P. W. Voigt,
- F. P. Horn and
- C. L. Dewald2
Despite the importance of weeping lovegrass, Eragrostis curvula (Schrad.) Nees, in Argentina, South Africa, and to a lesser extent in the United States, much remains to be learned about its forage quality. The objectives of this research were to evaluate: a) forage quality of four weep ing lovegrass entries, b) seasonal patterns of forage quality, and c) effect of stage of first growth and age of regrowth on forage quality.
Field experiments were conducted on an Enterprise loam (Thermic Typic Ustochrepts) soil at Woodward, Oklahoma. ‘Morpa’, ‘Ermelo’, common, and 673 were harvested under three managements: a) jointing stage and four subsequent 28-day intervals, b) heading stage and three subsequent 34day intervals, and c) anthesis stage and two subsequent 45-day intervals. In vitro dry matter disappearance (IVDMD), crude protein, cell contents (CC), hemicellulose, cellulose, and permanganate lignin (PL) were determined. Results were analyzed by ANOVA and regression procedures.
Morpa and Ermelo were similar and higher in IVDMD than common and 673. This higher IVDMD was correlated with lower PL and dry matter contents. Maturity differences among entries did not account for all entry variability in forage quality. Nongenetic correlation coefficients showed that high IVDMD was associated with high crude protein and CC and low cellulose, PL, and dry matter. Seasonal trends in forage quality showed that from jointing to anthesis IVDMD declined 0.46 percentage units per day. Following the initial harvests, IVDMD continued to decline at 0.02 percentage units per day during the remainder of the summer, despite equal interval regrowth harvests. Similar patterns were found for crude protein and CC. Hemicellulose also decreased from jointing to anthesis but then increased during regrowth harvests. Cellulose and PL increased from jointing to anthesis, but showed only small seasonal changes during regrowth harvests. Increasing age of regrowth resulted in lower IVDMD (—0.28 percentage units per day), crude protein, and CC, and higher cellulose and PL. However, changes were more gradual than from joint to anthesis.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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