Regrowth Interval and Cultivar Effects on Herbage Accumulation and in Situ Disappearance of Perennial Peanut.

Perennial peanut (Arachis glabrata Benth.) is a widely used warm-season legume in Florida. Recent researches have shown the potential forage accumulation and nutritive value of the genotype ‘Ecoturf’; however, there is limited information about the regrowth interval effects on herbage accumulation (HA) and nutritive value. The experiment was conducted in Ona, FL, from July to October of 2014 and 2015. Treatments were the factorial arrangement of two perennial peanut genotypes, ‘Florigraze’ and ‘Ecotuf’, and three regrowth intervals, 4, 8, and 12 wk, distributed in a randomized complete block design with four replicates. Herbage accumulation was estimated from a 0.75 m^-2 sample harvested at a 4 cm stubble height. The in situ technique was used to estimate the DM disappearance. Samples of were incubated in two steers (Bos sp.) for 0, 3, 6, 9, 12, 24, 36, and 72 h and the data was fitted in the non-linear model of Ørskov and McDonald (1979). The DM fractions were: A, rapidly degradable; B, potentially degradable; and C, undegradable. There was a cultivar × regrowth interaction for HA. Ecoturf increased HA from 4 to 12 wk (from 1.6 to 3.4 Mg ha^-1), while Florigraze increased HA from 4 to 8 wk (from 1.2 to 1.9 Mg ha^-1) and was similar between 8 and 12 wk. Ecoturf HA was greater than Florigraze at 8 and 12 wk regrowth. Fraction A was greater for 8 than 4 and 12 wk, and there was no difference between 4 and 12 wk (358 vs. 308 g kg^-1). Ecoturf had greater fraction B (451 vs. 412 g kg^-1) and lesser fraction C (226 vs. 261 g kg^-1) than Florigraze. Ecoturf can be managed at greater regrowth intervals with greater HA and nutritive value than Florigraze.