Harvest techniques change annual warm-season legume forage yield and nutritive value
Comparison among warm-season legume forage trials may not be valid if harvest techniques vary. To address this question, herbage dry matter (DM) yields, branching, crude protein (CP), and fiber concentrations for nine warm-season annual herbaceous legumes were measured by hand-plucking all leaves and pliable tips or clipping at 7.5- or 15-cm height. The experiment was conducted in Texas on a Windthorst fine sandy loam over 2 yr. Harvest technique did not affect DM yield in 2004, but the hand-plucked harvest technique produced 34 to 39% less forage in 2005 (low rainfall year) compared with the clipped plots. Most entries had greater branching on hand-plucked than on clipped plants (entry by harvest P < 0.05). Crude protein concentration was greater (P < 0.05) and fiber concentrations lower in the hand-plucked compared with the clipped plants. These results suggest that neither yields nor nutritive values of hand-plucked forage trials examining annual warm-season herbaceous legumes should be compared with clipped forage trials, whereas clipping heights may be less problematic. Results support a careful choice of experiment harvest technique based on the future field-scale harvest method or degree of target herbivore selectivity.