The immediate news might not be the best you have heard lately, but with a normal spring it will all quickly fade away.
However, Agriculture Victoria senior research scientist Hari Dadu says getting it right will require some serious attention to detail in your paddocks – now.
Talking to North West Farmer after presenting at the latest GRDC grower updates, Dr Dadu warns the “unusually early” outbreak of Septoria across the Wimmera and Mallee is presenting a major challenge for wheat growers.
And Dr Dadu says there are also signs of powdery mildew in wheat and net blotches in barley crops.
He says excessive rains during spring 2022 across the Mallee and Wimmera caused high disease levels and eventually resulting in high inoculum loads to infect crops this season.
“And then we get to 2023 and it is all wet again and we are back facing the need to already be considering foliar fungicides this season,” Dr Dadu says.
“Everyone has been saying we were in for a much drier year, but we certainly haven’t seen that yet,” he says.
“Growers need to get out in paddocks and start looking for those tell-tale signs and have, in place for each variety being grown, particularly if it’s susceptible to disease, an effective management plan.
“That might mean fungicide applications at the strategic growth stages such as stem elongation and flag leaf emergence. Your first foliar spray may be necessary, with the second one recommended, especially if we end up with a wet spring again.”
Dr Dadu recommends the best first line of defence is using resistant varieties, which he says gives good protection from disease and less reliance on fungicides.
He says to best estimate risk at paddock level and make informed decisions, growers need an understanding of:
• Paddock history
• Variety resistance
• Time of sowing
• Conditions that favour disease
• Monitor crops for symptoms
• Assess the benefits of fungicide application
“Any strategy in general should reflect varietal resistance and seasonal conditions to maximise yield benefit,” Dr Dadu added.
Dr Dadu says growers should also be aware of septoria’s growing insensitivity to fungicides. While resistance to Strobilurins has not been found in Victoria yet, the frequency of reduced sensitivity or resistance to DMI fungicides is increasing within in our state.
He says this can be better managed by the rotation of Group 3 fungicide mode of actives where more than one is required in a season.
“It’s a bit early to say if we will have a wet or dry spring, and there is no stripe rust around the Mallee yet, but when it does appear, there are few options to slow it down.
“Right now the colder, wet weather tends to hide it but we might see some when the temperatures start to rise as we head into spring, Scald and leaf rust in barley could also be a problem later in the year and that will need fungicides to control it,” he explains.
“The current prediction is for an average year on the back of the good subsoil moisture we have had in most areas, and provided it stays on track and spring is not too wet, or dry, and there has been strategic use of fungicides, that’s what we should get.
“We will need some rain at flowering and during spring, around September, in the southern Mallee, but perhaps a bit more in the north, which doesn’t have the same strong subsoil profile.”
