03-05-2025
Winter wheat: The drive to prevent septoria is on
The coming days will see winter wheat growers throughout Ireland push to keep septoria out of their fast-growing crops.
And it is all about getting an effective fungicide application on to wheat at the all-import leaf three emergence stage.
Teagasc tillage specialist, Shay Phelan, addressed the issue at a farm walk hosted by Limavady cereal grower, Andrew Blair.
As part of his presentation, he dissected a wheat tiller in order to fully identify the emerging leaves and the fast-developing ear within the plant.
Andrew Blair is growing Graham winter wheat this year, drilled last October at a sowing rate of 200kg/ha.
But according to Shay Phelan, septoria is not the only disease threat confronting winter wheat crops at the present time.
Septoria and other disease threats
The Teagasc agronomist explained: 'Whatever gene is involved in the resistance against yellow rust has broken. This was recently been confirmed by the National Institute of Botany in the UK.'
The varieties involved are Champion, Spearhead, Fitzroy, and Bamford.
'Graham is susceptible to yellow rust at younger growth stages. But resistance against the disease grows as the plants mature,' Phelan said.
'We don't think that Graham has been impacted by the yellow rust breakdown that has impacted other varieties.
'On the upside, the recent dry weather has helped to keep yellow rust at bay in most areas.'
Where wheat yields are concerned, the Teagasc agronomist indicated that the top leaves within the crop are the most important.
Attending the Limavady farm walk (l-r): Andrew Blair (host) and John Purcell, Ballyquin, Limavady
'The flag leaf accounts for 40% of overall yield, In the case of leaf 2, the figure is 25% with leaf 3 delivering 10% of total grain yield,' he added.
'This is why fungicide strategies are more important in wheat than is the case in barley.
Phelan also stressed that these products must be used in a strategic manner.
'Their overuse will lead to a reduction in overall activity,' he said.
'This is why their use must coincide with those periods when they will deliver the greatest impact.
'Using the same chemical on a number of occasions during the same growing season will quickly lead to a reduction in fungicide efficiency and impact within crops.
'Making sure that all of leaf 3 receives a fungicide application is extremely relevant in this context.'
An important theme of the 2024/25 growing season for winter wheat is the wide variations in growth achieved by different crops.
'This trend is noticeable within fields in the same area,' Phelan further explained.
'And this is why growers should walk individual fields and manage them on that basis.'
