The latest Teagasc crop report confirms that septoria is a problem within many stands of winter wheat, echoing a similar report from the Agriculture and Horticulture Development Board (AHDB).
The majority of winter wheat sown prior to mid-October has had its leaf-three fungicide application in the last seven to 10 days.
Septoria levels are above normal in most areas with infection common on leaf-four in crops in the south.
There are still a few reports of yellow rust in Graham, which needs specific and immediate intervention.
Septoria and other disease
Growth stages within crops vary depending on sowing date and location. However, leaf-two is well emerged in most locations while more advanced crops are at flag-leaf emergence.
Based on current growth rates, leaf one will be fully emerged and ready for fungicide around five to 10 days, according to Teagasc.
Meanwhile, the majority of winter barley is at various stages of awn emergence.
Awns are almost fully emerged in early developing varieties like Joyau, while awns are beginning to emerge on slower developing and later-sown crops.
In common with recent seasons, rhyncosporium, net blotch, and mildew are relatively well controlled at this stage.
Low levels of septoria nodorum are common across varieties and there are some reports of ramularia.
The target of the final fungicide on winter barley is ramularia. This is to preserve green leaf area in the upper canopy.
Teagasc research shows that the most effective control of ramularia comes from fungicide application at awn emergence and that later fungicide application at heading results in poorer control of the disease.
Weather impact
According to Teagasc, there are large variations in growth stages in winter oats due to last autumn’s protracted sowing period.
However, some earlier sown crops are at flag-leaf stage.
There is evidence of stress in many crops which is mainly due to a combination of cool weather and application of plant protection products – especially growth regulators.
Instances of mildew and crown rust have been reported, but fungicides have given good control.
Mildew and crown rust will still be the target at the final fungicide timing.
Where oilseed rape is concerned, crops are generally between the full flower and flowering declining stages.
According to Teagasc, yield potential is positive, with very few bare patches in fields and good branching.
Sclerotinia is the main disease threat at this stage where risk factors exist. These are: The presence of spores, warm humid weather and petal fall during wet conditions.
Current weather conditions will favour sclerotinia, where inoculum exists. Some growers managed to apply fungicide in the last week but some crops remain to be sprayed.