Estimating the economic cost of weeds in Australian annual winter crops

Abstract

An analysis of the annual costs of weeds in seven winter crops across Australia demonstrated that the most important 15 weed species cause substantial annual costs in both financial and economic terms. Using survey data captured over the 1998-1999 growing season, the financial cost of these weeds in seven crops was estimated to be AU$1,182 million. The main components of this cost were herbicides (AU$571 million), the competitive effects of residual weeds (AU$380 million), and tillage (AU$206 million) while weed contamination of grain was a minor cost (AU$25 million). Across all regions, the most economically important weeds were annual ryegrass, wild oats, and wild radish, although there were regional differences in importance. An economic surplus analysis determined the annual economic cost of weeds in annual winter crops to be AU$1,279 million. This surplus loss represented 17% of the gross value of Australian grain and oilseed production in 1998-1999. Australian grain producers incurred a major loss, with a reduction in producer surplus of AU$1,047 million. Australian grain consumers had a large consumer surplus loss (AU$229 million), while international consumers suffered a small loss and international grain producers gained a small producer surplus from the higher grain prices.JEL classification: D60, Q11, Q16

Measuring the effectiveness of management interventions at regional scales by integrating ecological monitoring and modelling

“…Arable weeds are a worldwide problem for crop production and are costly in terms of yield reductions, in addition to the financial costs of the machinery and chemicals needed to control them –. Moreover, there are indirect costs associated with weeds; for example, some rotational or management combinations are not possible when weeds are an established problem.…”

A survey of management and economic impact of weeds in dryland cotton cropping systems of subtropical Australia

“…The aggregated estimates of financial and economic costs associated with current weed infestations in dryland cotton cropping systems were also substantial, although not as large as the $151.7 million estimated for wheat in grain cropping systems in the same Survey of weeds in dryland cotton rotations region (Jones et al 2005). This is due at least partly to the much larger area of wheat sown in southern Queensland and northern NSW compared with dryland cotton.…”

“…This was based on the economic framework described by Jones et al (2005) that was adapted from McInerney (1996). Weeds have a direct financial impact by either increasing production costs or reducing income through lower yields.…”

“…Charles (1991) calculated that the annual costs of weed control in irrigated cotton was $161/ha for the crop and $7/ha for the fallow, based on cultivation, herbicides used and chipping. More recently, Jones et al ( , 2005 calculated that weeds cost $60/ha for wheat in Southern Queensland and northern NSW, based on weed control expenditure and losses due to residual weeds and contamination. This paper reports the results from a postal and a field survey of weed diversity and abundance, management practices and their effectiveness, and the estimated financial and economic costs of these weeds in crop rotations with dryland cotton.…”

Inheritance of evolved clethodim resistance in Lolium rigidum populations from Australia

“…The intensive use of herbicides for weed control has resulted in the evolution of herbicide resistance in many weed species. Lolium rigidum (rigid ryegrass) is one of the most troublesome herbicide‐resistant weeds in the cropping regions of Australia . The success of L. rigidum in Australian grain production is a result of its adaptability to diverse environments and its high fecundity .…”