Turnip Yellows Virus (TuYV) is becoming increasingly challenging to control as the main vector, the peach potato aphid (Myzus persicae) has developed resistance to pyrethroids, and the disease is becoming more widespread across the British isles.
This corresponds to increasing levels of infection; since 2016, Limagrain UK along with industry partners – Agrii, Openfield and the AICC – have been monitoring levels of TuYV in crops across the UK.
Sampling is carried out twice during the growing season, with an initial small-scale survey conducted in Oct-Nov, followed by extensive testing carried out in early spring.
“TuYV incidence reached its highest level ever last season, with 84% of non-TuYV resistant UK crops infected in early spring 2019. Almost all sites had an infection rate between 81-100%,” explains Dr Vasilis Gegas, Limagrain’s European oilseed rape portfolio manager.
“Incidence was highest in East Anglia and south east England.”
What’s the solution? Genetic resistance, points out Dr Gegas.
This year’s AHDB Recommended List for oilseeds has eight varieties with TuYV resistance.
“Over the past few years, there’s been huge genetic improvement in breeding for TuYV resistance, meaning that Limagrain’s TuYV resistant varieties have moved from the bottom of the yield pile since the launch of Amalie in 2014 to the top by quite a margin. Today, TuYV resistant varieties sit amongst the highest yielding varieties on the 2020-2021 AHDB Recommended List,” says Dr Gegas.
What to grow? The first decision to make is whether to go for a conventional or hybrid variety.
Yielding 106% over control, Aspire is the only conventional variety on the RL that carries the TuYV resistance gene. Aspire is short and stiff-stemmed and therefore easier to manage which we know is one of the key reasons growers opt for conventional varieties.
Aurelia and Ambassador are both good hybrid choices, suitable for September sowings. Both are trait-loaded varieties that provide high resistance to pod shatter, TuYV and stem canker. Aurelia is the only variety with twin “8” ratings for light leaf spot and stem canker on the AHDB Recommended List 2020-21.
|Gross output (% treated control)||108||108||107||106|
|Oil content (%)||45.3||45.2||45.7||45.7|
|Shortness of stem||6||6||5||7|
|Earliness of flowering||7||7||6||7|
|Earliness of maturity||6||5||6||5|
|Light leaf spot||7||8||6||7|
Source: AHDB Recommended List Winter oilseed rape 2020/21
For more information on any of these varieties, click here