Growers should complete the main nitrogen (N) application as soon as possible before growth stage (GS) 32, according to latest updates from Teagasc.
This generally equates to half the total amount of N for the crop if a three-split programme is being used. It is typically in the range of 100-125kg/ha (80-100 units/ac).
However, this may well be slightly lower this year and will depend on the breakeven ratio (BER).The final split should be applied at the flag leaf stage.
Where a two-split N programme is used, the application at GS32 should bring the crop up to its final amount.
A plant growth regulator (PGR) should be applied to wheat crops by first node (GS31). The temptation may well be to cut corners with plant protection products to reduce costs this year.
But this should only be done if N rates are reduced, which will lower lodging pressure.
PGR options include: CCC 75% at 2.0L/ha plus or minus an adjuvant; K2 at 1.8L/ha; or, CCC at 1.0L/ha plus Moddus 0.2L/ha or Meddax Max 0.2kg/ha.
Temperatures need to be greater than 8° for best effect.
Where fungicide programmes are concerned, long-term Teagasc trials have shown little or no yield response to a T0 application.
This is definitely an area where savings can be achieved, especially in first wheat crops.
Septoria is resistant to all the strobilurins at this stage. So it is pointless using them on wheat unless yellow rust is evident, in which case Comet and Fezan can be applied.
According to Teagasc, fungicide should be applied when the third-last leaf is fully emerged. Growth stage may not be an accurate indicator of the actual leaves present in the crop.
So dissecting plants and identifying the correct leaf to apply the first fungicide is critical for optimum septoria control.
Advice for growers
There have been occasions in previous years where the timings were incorrect which in turn had a negative impact on septoria control.
Growers are advised to make sure that they target the correct leaf before application of a fungicide.
The tank mix could include the multisite Folpet at 1.5L/ha plus 80- 100% of an SDHI/Qii mix, e.g., Questar, Revystar XL, Adexar, Elatus Era, Ascra Xpro. A mildewicide should also be included where mildew is present.
As pesticide costs have increased this year by between 10-20%, all inputs should be queried including adjuvants, bio-stimulants and even trace elements. These products can often be applied as a type of insurance.
It is estimated – based on the 2023 Teagasc costs and returns booklet – that it will take 9.2t/ha of winter wheat to cover costs, so there is little scope for extras.