Helping herbicides through harvest weed seed control
From farm laborer to leading academic
“Weed resistance is a massive problem that’s reducing food production worldwide,” Steve says. “But it’s also a manageable problem, as thousands of Australian grain farmers have experienced.” Steve’s top solution to the problem is non-chemical harvest weed seed control. “Pre-1940, no grain farmer would willingly allow weed seed to return to the field,” Steve points out. “Then came herbicides and farmers just let weed seed shoot out of the back of the combine harvester before spraying the weeds with herbicide when they grew. A pretty silly ‘solution’, in my view, because you’re just adding to the weed seed bank! With ryegrass, wild radish and many other weeds worldwide, the seed is still on the plant at harvest time. So crop harvest is a great opportunity to harvest the weed seed and not eject it out of the combine harvester,” Steve explains. “There are various harvest weed seed control solutions but they all work on the principle of funneling the seed away from the chaff stream for safe disposal.” One commercialized technique Steve mentions is the Integrated Harrington Seed Destructor, which intercepts the chaff stream and pulverizes the weed seed to prevent it from entering the soil seed bank. “I know Ray Harrington well. He’s a brilliant Western Australian farmer and a great innovator and agricultural engineer.” The various harvest weed seed control techniques now available are a fine example of the fruits of close collaboration between inventive farmers and knowledgeable academics.
Non-chemical help for herbicides
In Australia there is high awareness of weed resistance because it is a massive issue for grain farmers. “In countries where there’s less awareness, it’s mainly because weed resistance isn’t impacting farmers enough. But it will,” Steve says. “Our failure to get the message across to farmers is what has disappointed me most in my career. That’s why we now spend 30% of our research budget on communication measures.” Steve is under no illusions about how severe the resistance problem is worldwide: “The golden age of herbicides is over. Back in the 1980s, new herbicides were common and resistant weeds rare. Nowadays, new herbicides are rare and resistance weeds common. The low-hanging fruit has been picked. The chemicals we still have are precious and need to be protected. That’s where I see a vital role for harvest weed seed control – in helping herbicides.”