Feathertop Rhodes grass is quickly becoming one of the biggest weed threats in Australian farming systems, demanding swift and decisive action, according to weed researcher Bhagirath Chauhan.
Dr Chauhan, who is from the Queensland Alliance for Agriculture and Food Innovation, said the vast number of seeds produced per plant and the species’ ability to germinate and establish on very small rainfall events, gives this weed a real competitive advantage, particularly in a fallow situation.
“Night temperature does affect seed production of feathertop Rhodes grass so it is important to concentrate efforts on preventing germination or controlling these weed populations in spring and early summer,” he said.
“These early germinated populations are also more able to compete with summer crops and then set seed in-crop.”
Being able to tolerate both knockdown and residual (pre-emergent) herbicides, feathertop Rhodes grass can quickly gain a foothold in no-till farming systems.
“We also found that FTR grass seed on the soil surface is not viable after 12 months,” Dr Chauhan said.
“Burying the seed lengthens the period that the seed remains viable, so unless the seed bank is completely buried to a depth of 5 cm or more and left undisturbed for more than 18 months, cultivation on its own might not be a good control tactic.”
Feathertop Rhodes grass is already widespread across Australia and it is easily transported to new areas on machinery and in hay.
Roadsides, water channels, head ditches and on-farm tracks are all sources of weed seed, which can then easily enter cropping areas.
“If hay is brought in, it is wise to feed-out in defined areas so any FTR grass plants can be more readily seen and removed before they set seed,” Dr Chauhan said.
For more information about feathertop Rhodes grass control, visit: www.weedsmart.org.au