Finding new and successful strategies to control the spread of the obnoxious crop-competing weed ryegrass has become the main driver for a Spalding family’s integrated weed management plan.
Ryegrass affects almost all of Ben and Damien Sommerville’s 2500 hectare cropping area, and for the past 15 years the third-generation farmers – with the help of their parents Eric and Judith, and Damien’s wife Ruth – have carefully created a weed management plan that suits the operation.
Cropping canola, wheat and barley, problematic ryegrass paddocks are also managed by sowing oats for hay and silage.
Ben said although a chemical approach to weeds was used, the introduction of mechanical strategies had made a massive difference to ryegrass control efforts.
“If we have a bad paddock we will have hay followed by silage, or silage two years in a row – but we have to be mindful and put the stubble back into the paddocks as well,” he said.
“With the standing oats we come through and chop it off to take the ryegrass with it, so although there is a big removal of stubble in those years we are more on top of the weed with that practice, rather than letting it set seed in consistent years.”
Growing a pulse crop was also originally supposed to be a part of weed management because of the option to spray grasses in-crop, but Ben said those chemicals had lost potency.
Ben said he then had to rely on crop competition and spray topping instead, but because chickpeas in particular grow slowly, the required crop competition did not occur.
“The reason we grew a legume or pulse was for ryegrass control, we would top the legumes out to get a good kill on the weed later on in the season but the timing for chickpeas was wrong,” he said.
“The crop finished too late – the ryegrass had already set seed by the time the chickpeas were ready to spray top.”
Livestock agistment is also a part of the Sommervilles’ weed management strategy, as well as a pest management plan.
During the summer months sheep are used to control weeds and clean up fallen grain after harvest has finished to help decrease mice populations.
Operating a minimum-till system aids water conservation, and Ben said this was also an integral part of weed management.
“By retaining stubble and using a deep blade system for seeding we are not exposing moisture and we are able to control summer weeds better,” he said.
MANY TOOLS USED TO REMAIN AHEAD
AS THE need to find solutions to the challenges posed from consistent weeds and pests increase, third-generation Spalding farmer Ben Sommerville believes “a blanket approach will not work”.
Battling ryegrass-infested paddocks, wild radish, snails and mice each season, Mr Sommerville has decided to incorporate multiple strategies while also remaining on the lookout for new tools to help ease the impact on crop yield.
He said snails were a persistent pest in canola crops and therefore during the summer months of January and February canola paddocks are rolled to knock the snails onto the ground to dehydrate them.
“We roll the stubbles because snails climb up and attach to it and then seal themselves off, so by knocking the snails onto the ground we break the seal,” he said.
Mr Sommerville said all growers needed to find a method that worked in their system, but this did not mean just chemical usage.
“Whether it is burning, baiting, bashing or chemical, we have to try absolutely everything there is available,” he said.
“We are very aware of over-using chemicals in our system so we do not use insecticide if we do not have to, it is not just a blanket approach.
“There are mechanical options that could be used in the future such as the Harrington Seed Destructor which is a weed-seed smashing harvest tool but it is a big upfront cost.”