Increased carrier volume and reduced crop residue for improved trifluralin efficiency
Document Type
Conference Proceeding
Publication Date
9-2014
Conference Title
19th Australasian Weeds Conference
Place of Publication
Hobart, Tasmania
ISBN
978-0-646-92454-0
Keywords
Conservation farming, crop residue, no tillage seeding system, water rate, water sensitive paper.
Disciplines
Agricultural Science | Agronomy and Crop Sciences | Weed Science
Abstract
Pre-emergent herbicides are generally less effective in no tillage farming systems due to high levels of crop residue. However, performance can be improved if the herbicides are applied with a high carrier volume. This research investigated the interaction of carrier volume and height or spacing of crop residue on the control of annual ryegrass with trifluralin. To create plots with varying crop residue characteristics in 2011, wheat was sown in 2010 using a narrow row spacing, wide spacing or left bare (i.e. not sown to wheat), at Wongan Hills and Cunderdin, Western Australia (WA). The wheat was harvested to produce tall, medium or short crop residue. Annual ryegrass seeds were broadcast onto each site in 2011 and trifluralin was sprayed using 50, 75 or 100 L ha−1 carrier volume (directly prior to sowing). Increased carrier volume increased spray coverage at both sites (average cover of 9.0%, 15.0% and 25.5%), leading to improved control of annual ryegrass (average density of 24, 19 and 11 plants m−2). However, altered row spacing or harvest height in 2010 (i.e. altered crop residue characteristics) did not consistently affect spray coverage. Reduced crop residue height or increased row spacing improved annual ryegrass control at Cunderdin but had no impact at Wongan Hills. It is clear that carrier volume has a more consistent impact on the performance of trifluralin than crop residue (in WA where the biomass of crop residues is relatively low). These results are encouraging as it is usually easier for growers to increase carrier volume than to adjust crop residues, for improved annual ryegrass control in no tillage systems.
Recommended Citation
Borger, C,
Riethmuller, G,
Ashworth, M,
Minkey, D,
and
Hashem, A.
(2014), Increased carrier volume and reduced crop residue for improved trifluralin efficiency, 19th Australasian Weeds Conference, Hobart, Tasmania, pp.83-86.
https://library.dpird.wa.gov.au/conf_papers/309
