Getting a fungicide on to oilseed rape is a priority for Rozzi Martin and she also discusses cereal drilling progress and grassweed control options in cereals
This month’s update includes information on:
North of Manchester conditions have been horrendous for the last two months, with a lot of rain meaning many growers are only 20-50% drilled up. Storm Ophelia didn’t bring much rain, but its wind helped dry ground out and many grabbed the chance to get some wheat in the ground during a short window before it rained again. Further south many are drilled up and crops are looking good.
Where wheat is yet to be drilled, there are some rough seedbeds and with temperatures falling and the potential for more rain, it could be time to switch to spring drilling. Assess conditions on a field-by-field basis before making any decision.
Where pre-emergence herbicides haven’t been applied to wheat, try and get them on as soon as possible. If you need to go peri-emergence, plants are small and can be vulnerable, particularly with the arrival of recent frosts, so you need to balance being robust with crop safety. In these situations, dropping out Defy (prosulfocarb) out of the mix and opting for a simple base of Liberator is advised.
In this part of the world, the number one grassweed is brome and it is vital to know your species. A robust pre-emergence is important in both wheat and barley for brome control, but for wheat growers Monolith is a very strong option for brome control in the spring for any escaped or late germinating weeds.
Ryegrass is also a problem and in our resistant ryegrass-busting trial at Hale, near Liverpool we have been looking at pre-em performance. This season it looks like the addition of flurtamone and Defy have given the best results. A new product which is Liberator plus metribuzin also looks very strong.
Deter seed treatments will soon start to run out in the earliest-drilled crops, so growers will need to monitor for aphids and treat with a pyrethroid, but only where absolutely necessary, as it can take out any beneficial insect predators present in the crop.
It is a mixed picture with oilseed rape in the North West. Further north in the region where there has been a lot of rain, crops have struggled with wet feet and whole fields have been lost in some cases. Disease pressure is also high, with phoma spreading through crops and helped by the wet weather.
Fungicide options for now on will depend on what’s been applied so far. Where applying the second spray in a two-spray programme, a top-up of 0.32l/ha of prothioconazole is recommended. If there has been nothing applied so far, consider one application of Proline at 0.46l/ha to cover both phoma and light leaf spot.
We know light leaf spot comes into the crop early, but you won’t be able to see any symptoms yet. It is a good idea to take some leaf samples, seal them in a plastic bag and incubate to see if any disease appears. You can also use the Bayer and ADAS SpotCheck service to see if latent disease is present, with details on the website.
The weather is cooling down now, so risk will drop off, but continue to monitor for peach potato aphids and apply an aphicide such as Biscaya where they are present to prevent turnup yellows virus (TuYV) infection.
