Rhizoma peanut yield and nutritive value are influenced by harvest technique and timing
Rhizoma peanut (Arachis glabrata Benth.) is a warm-season perennial forage legume adapted to the southern USA. The objectives of this study were to evaluate harvest technique and timing on dry matter (DM) yield, crude protein (CP), acid detergent fiber (ADF), and acid detergent lignin (ADL) concentrations of rhizoma peanut. Two experiments (one without irrigation and one with irrigation) each with four replications were conducted during the 2004–2006 growing seasons (April–October) in north-central Texas on a Windthorst fine sandy loam. Treatments consisted of manually clipping all plant material three times throughout the growing season at 5-cm height with a July rest (5-JR) or a September rest (5-SR), four times throughout the season (June, July, September, October) at 10-cm height, or manual harvesting (hand-plucking) all leaves and growing tips to ground level four times throughout the season. Annual rhizoma peanut DM yield for the irrigated experiment (4710 to 10870 kg DM ha–1) was greater than the nonirrigated experiment (2750 to 9300 kg ha–1). In both experiments, the 5-JR treatment reduced rhizoma peanut DM yield in the third year by 29 to 37% compared with the hand-plucked and the 5-SR treatments. Harvest timing or technique did affect nutritive value although these differences were small, ranging from 186 to 204 g CP kg–1, 280 to 313 g ADF kg–1, and 57 to 65 g ADL kg–1. These data indicate that rhizoma peanut had high nutritive value regardless of treatment and maintained greater DM yield if harvested by hand-plucking or at a 5-cm height with a September rest.