IT’S time-consuming, another drain on cash flow following yet another poor year for many farmers and comes at a time when most grain producers are considering a well-earned break, yet the evidence is indisputable - summer weed control is a crucial task.
Trial work from the Birchip Cropping Group (BCG) showed that in 2008 there was a 50 per cent wheat yield reduction where weeds were allowed to grow over the summer months.
And with much of the Australian cropping belt receiving heavy rainfall over November and December that will not have been used by the winter crop, there is even more incentive than usual for farmers to control weeds and provide a valuable subsoil moisture bank for the following crop next year.
Generally, research indicates that as a rule of thumb around a quarter to a third of a summer rain event is available to the following crop.
For instance a 100 millimetre rain event would leave 25-33mm of plant available water next season.
Given the erratic nature of spring rainfall, some farmers in low rainfall zones now describe summer spraying as one of the most important operations of the cropping cycle in providing some moisture for crops should the season turn bad.
This year is no different.
Extract from report to appear in Stock & Land, January 15.