2017 inherited a generally high weed burden from 2016 and delivered the right conditions for them to flourish if left unchecked.
In the Mallee, the increase in area sown to pulses has brought with it increased numbers of weeds like sow thistle, fleabane, and prickly lettuce. Ryegrass is an ongoing issue, especially in the Wimmera, where two wet years have supported a build-up of grass weeds. Other established weeds, such as bifora, continued to spread into new paddocks, and issues with weeds like jersey cudweed, skeleton weed and fleabane suggested a changing weed spectrum in the Mallee.
Fortunately a wet start meant that pre-emergents and knockdowns worked well despite heavy stubble loads. In many cases, rain also allowed for an effective double-knock strategy. On the other hand, repeated frost events challenged many Mallee growers to get a good kill with Group A herbicides (eg. Brodal®). Better outcomes were reported in the case of Group B herbicides. Fleabane was difficult to control in the Mallee, and vetch in pulses caused issues in the Wimmera.
Late rains increased the potential for high inoculum loads carrying over into 2018, and high mice numbers made summer fallow management critical – but with wet conditions also delaying harvest, many growers faced the difficult decision of when to get off the header to spray!
