What is Turnip Yellows Virus (TuYV)?
Turnip Yellows Virus or TuYV for short is a virus that is transmitted through Oilseed Rape crops by the Peach Potato Aphid also known as Myzus Persicae.
Up to 72% of Peach Potato aphids can carry the disease, this means that a small aphid infestation can easily have a big impact on a crop.
What are the signs your OSR may be infected?
TuYV infection can happen in both the autumn and the spring, but symptoms are most often not seen until the spring.
There are several signs that could be a sign that your crop is infected with the virus, these include the following.
- Short or stunted plants
- Leaf margins becoming red and purple
- A reduction in primary branching
- Fewer seeds in the pod
Most importantly once the infection has happened it cannot be controlled.
What are the effects on yeild?
The overall effects and resulting costs of a TuYV infection cannot be ignored.
Infected crops will see both a reduced oil content and a 30% drop in yield, thus, in turn, resulting in lower margins.
What can you do to protect against TuYV?
Apart from walking the crops regularly, your choice of OSR variety will be key. There are now a number of both hybrid and conventional seed choices that have TuYV resistance.
Other measures you can take are
- Select your field carefully, ideally away from other host crops
- Encouraging predators of the aphid, although this can't eliminate the virus can control population numbers.
- Maintain 'green bridges' by destroying weed species that can act as a host.
- When selecting your drilling date consider air temperature and the virus-infection risk.
- Invest in monitoring tools to keep an eye on aphid activity
What is TuYV resistant?
TuYV resistance was first introduced from stubble turnips, the resistance halts the spread of the virus through the plant by preventing multiplication.
The resistance is based on a single major gene, the re-synthesised B.napus line 'R54'.