Growth Habit of Rhizoma Peanut Cultivars Affects Establishment and Spread When Strip-Planted in Bahiagrass Sods.

Planting of rhizoma peanut (RP; Arachis glabrata) into clean-tilled strips within bahiagrass (Paspalum notatum Flügge) pastures may provide an economical way to increase sward nutritive value, decrease dependence on N fertilizer for grass-based pasture systems, and promote the formation of sustainable, mixed-species swards in Florida. 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 response to grazing management strategies. In 2011, an experiment was conducted at the UF/IFAS Beef Research Unit in Gainesville, FL to quantify rate of establishment, spread, and grazing tolerance of RP cultivars within the context of strip planting. The experiment was a randomized, complete block design with a split-plot arrangement of treatments. Treatments included two defoliation regimes, haying or grazing every 28 d, and four RP entries. Entries were Arblick, Ecoturf, Florigraze, and UF-Peace (UFP). Total sprout emergence (# sprouts m^-2) was measured weekly beginning 3 wk after planting until defoliation was initiated on 15 June. Percentage of RP cover and frequency of occurrence were quantified prior to each defoliation event. Spread was measured at the end of the season in October. Total sprout emergence was greatest for Florigraze compared with all other entries.  Across the season, percentage cover and frequency of Florigraze were greater (40% cover and 80% frequency) than UFP (17% cover and 43% frequency) and Arblick (21% cover and 47% frequency), but were not different from Ecoturf (28% cover and 62% frequency).  Rate of spread was greatest for Florigraze and Ecoturf (0.31 and 0.34 m, respectively) compared with Arblick (0.15 m) and UFP (0.04 m). Management of RP did not affect cover and frequency as much as did RP genotype. However, spread potential was reduced by grazing (0.11 m) compared with haying (0.31 m) treatments. Results of this experiment suggest that strip-planting may be a viable option for establishing RP–grass associations in the southeastern USA.