Prospects to select tall fescue with a low silica concentration

Abstract

Although not essential to most plant species, silica plays an important role in the protection of plants against different types of stress. In monocots, the main role of silica is protection against herbivores. Although the mechanisms are not fully understood yet, it is clear that silica discourages the grazing of herbivores. Hence, high silica concentrations are unwanted in forage crops and grasses that are grown as a feed for ruminants. In this paper, we explored the possibilities to select forage grasses with a low silica concentration. In a yield trial comparing five forage grass species under cutting management, we found the highest and lowest silica concentrations respectively in tall fescue (Festuca arundinacea Schreb.) (0.7 % averaged over all cuts) and perennial ryegrass (Lolium perenne L.) (0.35 % averaged over all cuts). We found a negative effect of the silica concentration on digestibility of the organic mass (DOM). This effect was particularly strong in the first cut: -4.9 % points DOM per 0.1 % points in silica concentration. In a screening of tall fescue nurseries for silica concentration, a range between 0.05% and 1.57% was found and there was a weak negative correlation between DOM and silica concentration. Based on a progeny test, a narrow sense heritability for silica concentration of 0.78 was calculated. Given the presence of both variation and a high heritability, selection for lower silica concentrations in tall fescue is promising. The simultaneous selection for DOM and low silica content offers good perspectives to improve the feeding quality of tall fescue.

Designing agricultural grasses to help mitigate proteolysis during ensiling to optimize protein feed provisions for livestock

“…It may consequently also have high silica content. In contrast, amongst the grasses studied, Cougnon et al ( 2020 ) found perennial ryegrass to contain the lowest concentrations of silica. Although at this stage speculative, possible respiration rate and silica content differences between the grasses could influence DM losses during wilting of Festulolium spp.…”

“…Although previously considered a negative trait for intake of grass forage by grazing animals, silica content is now receiving new attention as a means of diversifying grasslands to combat the impact of climate change (Volaire et al, 2014). In a study by Cougnon et al (2020) comparing silica concentrations in different forage grass species, the highest silica concentrations were found in fescue, albeit in tall fescue (Festuca arundinacea Schreb.). Although its silica content has not yet been reported, F. arundinacea var glaucescens is a progenitor of tall fescue and has contributed two of its three ancestral genomes (Humphreys et al, 1995).…”

Measuring Fluorescence as a Means to Evaluate the Physiological Reaction to Growth Retardant Applied to Manage Turf

“…Its significant advantage is forming rhizomes, which are more resistant to tearing, facilitating easier recovery (if tears happen) compared to the bunch-type perennial ryegrass or tall fescue [2]. Tall fescue creates a deep root system, making this species the most tolerant to drought among the three investigated species [3,4].…”