The plant growth regulator, trinexapac‐ethyl, increases seed yield in annual ryegrass ( <i>Lolium multiflorum</i> Lam.)

Abstract

ABSTRACT The plant growth regulator trinexapac‐ethyl (TE) is widely used to increase seed yield by reducing lodging in many grass species, including perennial ryegrass ( Lolium perenne L.) and tall fescue ( Festuca arundinacea Schreb.). However, the seed yield responses of annual ryegrass ( Lolium multiflorum Lam.) to TE has not been widely investigated. In four field experiments, different rates of TE (between 0 and 800 g ha −1 ) were applied and the plant response measured. Seed yield was significantly ( P &lt; 0.05) increased above the control by all TE treatments with an average response of 51% and 65% for the 200 g and 400 g TE ha −1 treatments, respectively. The seed yield response was associated with reduced lodging and shorter stems contributing to 1.1 more seeds per spikelet attaining saleable weight resulting in 72% more seeds m −2 . The plant growth regulator TE can improve seed yield in well‐managed stands of annual ryegrass.