BURNING the midnight oil could well solve a major problem for Irish farmers, especially those involved in cereals. New research in the US has shown that ploughing at night can dramatically reduce the number of weeds competing with farming crops.
That reduction has been found to be as high as 80 per cent in certain weed emergence, but in general terms reductions of between 50 to 60 per cent were achieved.
The theory is simple. Light penetrates the soil as it is being turned allowing buried weed seeds to break out of dormancy. With some types of weeds, denying light at the time of ploughing reduces sprouting, research in the states of Minnesota and Iowa found.
But the man who led the research for the US Department of Agriculture, Mr Douglas Buhler, found there is one major problem with night ploughing.
"To achieve the levels of reduction we are talking about, ploughing must be done in absolute darkness," he told the US Department of Agriculture research magazine.
"Just a brief exposure to a little light from tractors or possibly a full moon may trigger weed seeds to sprout like they do in daylight."
In one experiment, Mr Buhler and his assistant used military night vision goggles for after dark ploughing in Minnesota. The research showed so much promise that they duplicated the experiment last year, and data from the second experiment substantiated the initial findings.
In both cases, no chemical weed controls or herbicides were applied but nevertheless there were substantial reductions in small seeded broad leaf weeds, including common ragweed, black nightshade, common lamb squarters, pigweed, smartweed and wild mustard.
Dr Jim O'Mahoney, Teagasc's village expert, said yesterday he was impressed by the US data produced. Virtually all these weeds created problems for Irish farmers but he could not see them going out in the dead of night to plough. "However, it would appear to have limitations outside the laboratory because ploughing would have to be done on nights when there was no moon."
He said the US research ploughing had been done between II p.m. and midnight and even if ploughing time could be extended to 3 a.m to avoid light, there would not be enough total darkness available to Irish farmers to plant their crops in this way.
"I think it's not too practical but it's interesting, especially for those farmers who might suffer from insomnia or for gardeners who want to get rid of weeds," he said. "On the other hand, I can imagine the guards being called if neighbours found tractors creeping around at night without lights."