EFFORTS to control one of the world's worst agricultural weeds in the Mackay district are showing promising results.
Red witchweed was first discovered in Mackay in 2013 with eight properties found to have infestations.
Witchweed species are small, parasitic herbs and are a major pests of grain crops in Africa, where they cause an estimated $7 billion damage each year. Witchweed species rank as some of the world's worst agricultural weeds.
Red Witchweed National Eradication Program project manager Peter Austin said the treatments his team are carrying out on the infected properties are proving to be effective in controlling the pest weed.
“The eradication program consists of a range of treatment methods, including planting ‘false crops’ and soil fumigation, as well as comprehensive surveillance,” Mr Austin said.
“The false crop we are using is soybean as it acts as a host and triggers germination of red witchweed seeds but doesn’t let the seeds attach to the roots. This reduces the number of seeds in the soil as they die and can’t germinate.”
Mr Austin said corn crop were also being planted intermittently throughout the area to find out if red witchweed was present, as corn is a true host of the weed.
“In autumn we fumigate the soil by injecting ethylene gas into the soil to destroy red witchweed seed,” Mr Austin said. “The gas also initiates germination of any seeds that are in a pre-conditioned state. A second soil fumigation is then applied to smaller areas using Dazomet in winter.
“The preliminary report which looks at the first year and a half of treatment verifies that these treatments are working to effectively control red witchweed in the Mackay area which means we are on our way towards eradication.”