Establishment and Spread of Rhizoma Peanut Genotypes Strip-Planted in Bahiagrass Swards.

The addition of legumes to warm-season grass pastures may increase sward nutritive value and decrease dependence on costly N fertilizer in pasture-based beef cattle production systems. In Florida, planting of rhizoma peanut (RP; Arachis glabrata) into clean-tilled strips within bahiagrass (Paspalum notatum Flügge) pastures may promote the formation of sustainable, mixed-species swards while reducing RP establishment costs. Recently-released cultivars and germplasms of RP range in growth habit from decumbent to upright, which will likely affect their ability to spread in grass pastures and their response to grazing management strategies. A 2-yr establishment study (2011 and 2012) was conducted in Gainesville, FL to quantify rate of establishment, spread, and grazing tolerance of RP genotypes within the context of strip planting. The experiment was a randomized complete block design with a split-plot arrangement of treatments. All plots were fertilized according to soil test recommendations with P and K. Treatments included two defoliation regimes, haying or grazing every 28 d, and four RP genotypes. Genotypes were Arblick, Ecoturf, Florigraze, and UF-Peace (UFP). Total sprout emergence was measured weekly beginning 3 wk after planting until defoliation was initiated on 15 June 2011 and 14 June 2012, respectively. Percentage of RP cover and frequency of occurrence were measured prior to each defoliation event. Spread was measured at the end of the season in October of each year. Total sprout emergence was greatest for Florigraze compared with all other entries (79 vs. 51 sprouts m^-2).  Percentage cover and frequency of Florigraze (26% and 59%, respectively) and Ecoturf (25% and 59%, respectively) were greater than UFP (11% and 34%, respectively), but were not different from Arblick (19% and 47%, respectively). Although management of RP did not affect cover and frequency as much as did RP genotype, spread potential was reduced by grazing (0 m) compared with haying (0.24 m) treatments. Results of this experiment suggest that selection of RP genotype and management during the establishment year may affect the rate and success of establishment of RP–grass associations in the southeastern USA.