Herbicide Tolerance Options for Weed Control in Lanza® Tedera

Abstract

Tedera is a drought-tolerant perennial forage legume introduced in Australia in 2006. In October 2018, T15-1218 Lanza®, the world’s first tedera variety, was released by the Department of Primary Industries and Regional Development and Meat & Livestock Australia for commercial use. A key agronomic practise for the successful establishment and adoption of tedera is to have a robust herbicide package to control a range of grass and broadleaf weeds well tolerated by tedera. A total of 9 pre-emergent and 44 post-emergent herbicide treatments were evaluated in eight experiments from 2017 to 2021. To control grasses such as annual ryegrass (Lolium rigidum Gaud.), propyzamide and carbetamide can be recommended for pre- or post-emergent applications and butroxydim, clethodim, and haloxyfop for post-emergent applications. The broadleaf pre-emergent herbicides recommended are clopyralid to control emerged capeweed (Arctotheca calendula (L.) Levyns), fomesafen to control pre-emergent wild radish (Raphanus raphanistrum L.), and the double mix of fomesafen + diuron, flumetsulam + diuron, and the triple mix of fomesafen + diuron + flumetsulam to control pre-emergent capeweed, pre- and post-emergent wild radish, and other broadleaf weeds. The most consistently well tolerated post-emergent herbicides by tedera seedlings and adult plants were diflufenican, diuron, flumetsulam, fomesafen, and their two- or three-way mixes that will provide good control of capeweed and wild radish. Desiccants such as paraquat or diquat were also well tolerated by 1-year-old tedera plants that recovered after being desiccated.