Recent industry research1 has shown yield suppression in autumn-sown wheat from as few as 10 ryegrass seedheads per square metre.
Now, however, wheat growers using a well-known pre-plant herbicide to control wild oat infestation can be confident they’re tackling unwanted ryegrass populations at the same time.
Nufarm technical specialist Sonja Vreugdenhil says regulators have recently approved Avadex Xtra for suppression of ryegrass in wheat.
This addition strengthens growers’ toolkits for managing the risk of herbicide resistance.
It also provides another way to help safeguard wheat yields before the crop is planted.
Avadex Xtra is a Group 15 herbicide, and with the addition of ryegrass suppression to the label, is a great option if ryegrass resistance or tolerance has been suspected, she says.
Applied at the same rate as currently specified for wild oats in wheat (2.8 litres per ha), the selective herbicide will not eliminate ryegrass, but will reduce populations prior to their emergence, thus lessening potential seed burden.
“Control will be improved with a follow up application of an alternative grass herbicide registered in the sown crop. An additional pre-emergent herbicide will help fully control populations,” she advises.
Application technique and timing are very important.
“Growers need to be planning for this early, well before thinking about drilling their wheat crops.”
Best practice is to cultivate the soil to a fine, firm seedbed, apply Avadex Xtra, and incorporate it immediately and thoroughly after application to a depth of 5 cm.
It must be applied before wild oat and grass seeds have germinated, and growers are advised to avoid applying Avadex Xtra to wet soils, because this can cause uneven incorporation.
1FAR Cereal Research Results, 2021-22.