Recent rainfall and hail across the wheatbelt has heightened weed management issues for grain growers over the summer and into next season.
Department of Agriculture and Food research officer Alex Douglas has urged growers to assess their paddocks before or during harvest to determine what weed control measures are required.
Ms Douglas said the late spring rain would cause continued growth of existing winter weeds with potentially more seed set, plus an early germination of summer weeds prompting additional paddock management considerations.
“Growers whose crops were knocked down by heavy rain or hail should examine if weed or crop seed were knocked to the ground as seed that was in the head may now be on the ground,” she said.
“While some growers may be able to harvest lower to pick up these fallen plants, others need to be aware that their harvest weed seed management may not be as effective.
“Harvest weed seed management relies on having the majority of the weed seeds being captured by the header and then moved into chaff carts or incorporated into windrows.”
Ms Douglas said these paddocks could create problems for growers considering dry seeding next season.
“Growers would be wise to monitor and record data on these paddocks and factor this risk into their 2015 cropping program,” she said.
Summer crop plant volunteers from hay crops and early harvested paddocks could also pose a risk for diseases, like rust, especially if there is further rainfall.
“To reduce this risk growers will have to keep a close eye on their paddocks and spray out or graze any crop regrowth as soon as possible,” Ms Douglas said.
“Growers should also be aware that any weeds present during summer will deplete soil of stored water and soil nitrogen, so it is best to get onto control sooner rather than later.”
For more information visit agric.wa.gov.au and search for ‘summer weed control’.
A recently released comprehensive manual, Summer Fallow Weed Management, can also be downloaded from the Grains Research and Development Corporation’s website.