These days I’m investigating a little bit deeper into the varieties of sugar beet being developed to combat virus yellows, how they perform with different strains of the virus that we find on farm.
I’m trying these against beet mild and beet chlorosis kept at the BBRO (which is the type of virus normally used for trials). This year I’ve also gone out and collected different samples of virus from across the UK and I’m challenging them with that as well.
For example, take a fodder beet leaf from Yorkshire that got sent into the lab. I tested it to identify it had beet chlorosis virus. I then fed a ‘clean’ aphid on it for two days and carefully transferred that single aphid onto a young, healthy sugar beet plant.
That aphid transmitted the virus into that plant. And that’s what I used to build up to get more plants, more aphids and ultimately in the spring this year, we took infected aphids out into the field and inoculated a field trial.
How much further to go?
I’ll be entering my final year in February and getting ready to hand-in my thesis at the end of January 2024.
What are you starting to reveal?
Within my field trial at Morley, hopefully harvested in the next couple of weeks, what we’re seeing is that varieties developed for beet mild are looking like they’re also staying greener under beet chlorosis as well.
Obviously, we won’t know until we see the yield, but there are some promising first early signs of that.
We need to be wary and mindful that there is variation?
Yes. There are some very small genetic differences between, for example, beet chlorosis I found in Norfolk, in Suffolk, or in Yorkshire.
They might have little changes in their genetic code, but we need to now work on whether those differences have any effect in terms of disease severity or whether they can escape mechanisms the plants are using to combat them. Certainly, in the field trial now we’re not seeing too many major differences in terms of symptom development, but I can’t really say any more until we’ve got the yield data in.
Has it been a quite a satisfying year?
Oh, definitely so. I was in the field at Morley yesterday and to be able to stand in a plot (where I’ve got in each treatment, two susceptible varieties and two resistant or tolerant varieties) and see that two varieties are noticeably greener and showing less symptoms than the other two is really satisfying and that’s really hopeful I think for the industry.
One of the really rewarding things I find doing my PhD is talking to growers, talking to industry at a wider level about what I’m doing and people saying “yes, that is useful”.
I went to the IIRB International Beet Conference in Belgium in June. What was fascinating was that no one else, anywhere, is looking at strains of these viruses. Everyone’s focused on just the single species and not really interested in seeing if there’s variation within them.
I presented on a poster some of my work, like at Morley where I have a field trial that has six different viruses. No one else anywhere, as far as I can tell, is working with three or four viruses, let alone six. So that’s really exciting.
The next big thing is getting my hands on that harvest data. It’s all very well me looking at symptoms within the field but at the moment I don’t know what’s going on underground. Getting my hands on that data and analysing it is the next big job.
Are you worried that the growing conditions of this year, particularly the long period of drought, may have distorted the results?
It’s been a tricky year for field trials. Not just that plants were under drought stress for a lot of the summer, but also that the temperatures were so high the crop was scorched as well as being dehydrated. The other issue is that when I returned from my honeymoon in August, the first day back I found 100% of plants infected with beet moth, which was a little bit horrifying. Some of the plants are starting to grow away from it. Some of them are already struggling, which is one of the reasons we’re going for an earlier harvest date than we planned.
However, because I know that not many plants were infected before I went away and all of them were infected when I came back, infection must have happened at roughly the same time across the field. So as a scientist, I can say ‘well, all plants were treated equally’. That evens out the impact.
I’m hoping that even though the yield might be lower than we would expect because of the beet moth and because of the drought, at least all plants should be affected equally. But yes, it’s been a real challenge this year. We had quite a high natural aphid pressure, so we were battling natural virus infection as well. I also had leaf miner at the cotyledon stage which was a little bit worrying as well.
Will you get another season’s data out of your PhD?
That’s a really good question. Because we’ve had so much interest in the field trial at Morley, there’s a big question about how and if we do it again.
As you can imagine, if we were to find that there was a particular strain of these viruses that the varieties didn’t combat as well, that would be really important for the industry to know about.
So, I’ve quite a few decisions in the coming weeks and months as to how we do that.
It validates the fact that my work is important and that’s marvellous.