Adaptability and Stability Analysis for Selection of Elephantgrass Clones under Grazing

Abstract

Adaptability is the capacity of a genotype to respond favorably to changes in the environment, while stability is the capacity to have highly predictable performance in different environmental conditions. In this study, the stability and adaptability of eight Pennisetum spp. clones were assessed. Genotypes analyzed in this research included five dwarf elephantgrass (Pennisetum purpureum Schumach.) cultivars (Taiwan 2.27, Taiwan 2.37, Taiwan 2.114, Merker México 6.31, and Mott), two tall elephantgrass cultivars (IRI 381 and Elephant B), and one interspecific hybrid (HV 241) of elephantgrass and pearl millet [P. purpureum × P. glaucum (L.) R. Brown]. Adaptability and stability parameters were estimated for the following variables: herbage mass (HM), herbage accumulation rate (HAR), number of green leaves per tiller (NL/T), number of tillers (NT), and leaf/stem ratio. Interaction between clones and grazing periods occurred (P ≤ 0.05) for all variables. Herbage mass ranged from 2180 kg dry matter (DM) ha−1 (Taiwan 2.37) to 3383 kg DM ha−1 (Mott), averaging 2796 kg DM ha−1. Except for HV 241, which displayed specific adaptability to a favorable environment in HM and NT, the clones displayed wide adaptability. Dwarf genotypes (Taiwan 2.27, Taiwan 2.114, and Mott) displayed greater (P ≤ 0.05) capacity of leaf production per tiller than the other entries. Mott and Taiwan 2.114 were selected for the next phase of the breeding program on the basis of stability, HAR, and NL/T.

Canopy structure and forage nutritive value of elephantgrass subjected to different stocking rate and N fertilization in the “Mata Seca” ecoregion of Pernambuco

“…There were no required intervals for the development of new leaves, reflecting in a decrease in leaf:stem ratio. The values found for leaf:stem ratio in this study were lower than those found by Viana et al (2015), who evaluated the stability and adaptability of eight Pennisetum spp. entries, and among them, the IRI-381 presented an average value for 16 grazing cycles of 0.86.…”

“…The intense stem elongation might have been triggered by greater pre-grazing stubble height. Rapid elongation of stem and internodes is a process that leads to the reduction of leaf:stem ratio, and this relationship is key in forage nutritional value evaluation (Viana et al, 2015).…”

“…This grazing cycle was based on previous research at the same location using elephantgrass under grazing. In the previous research, the grazing period was 32 days (Viana et al, 2015). In the current trial, we used 34 days to have a grazing cycle lasting five weeks and optimize sampling efforts.…”

Correlations Between Stability Statistics of Forage Production in Elephant Grass

“…Enhanced cultivars are a common need to dairy farmers across the country, and the demand for new forage cultivars adapted to different ecosystems is intense. Stability is the response predictability in different environmental conditions (Viana et al, 2014). Studies of stability parameters are important because they allow us to identify genotypes with predictable behavior and responding to environmental variations (Cruz et al, 2012).…”

Morphological characteristics and proportion of leaf blade tissues of elephant grass clones under sheep grazing

“…The increasing interest in the use of short clones in pasture systems is mainly attributed to their better prehension by animals and to the location of their apical meristems close to the ground, which reduces meristem decapitation and confers high persistence under grazing conditions (Resende et al, 2002;Silva et al, 2009;Viana et al, 2009;Araújo et al, 2011). However, there are few known reports on dwarf clones subjected to grazing by small ruminants (Viana et al, 2015).…”