Good prospects for BYDV-resistant wheats in the South West

Publish on August 30, 2023
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Growers in the south west, the main hotspot for barley yellow dwarf virus in the country, could have much to gain from BYDV-resistant wheats, says agronomist Neil Potts of Exeter-based Matford Arable Systems.

“Down here we start drilling mid September, so in theory growers should have applied four aphicides last season to control BYDV, but they put on three at most. They haven’t had a problem; where only one spray was applied BYDV has impacted the crop, but not disastrously. But there were a few disasters where growers didn’t get on at all.”

The biggest issue preventing widespread uptake of resistant varieties currently in this region is their Septoria resistance score, says Neil. “We tend to disregard anything that hasn’t got a minimum high 6, and preferably a 7 or 8, in front of it.

Bdv line versus non-Bdv line under extreme pressure

“BYDV resistance in wheat is brilliant and we could do with it in all wheats, but at the moment it is not included in varieties that will widely suit our area. Fungicides aren’t doing the job they use to do, so if you don’t have the variety onside you could well struggle.

“I’m not saying BYDV-resistant varieties don’t have a place at the moment. They will be used as a management tool where BYDV is perceived as a particular problem and there is no other way of dealing with it.

“For example, I have one customer who will grow all RGT Grouse this autumn. He’s farming land that he can’t use sprayer on once it starts raining in October, and he can’t get back on until February/March time. So Grouse will be a godsend for him.

“Another grower has grown RGT Wolverine in the past and it stopped the BYDV problem. He had one field on his home unit planted with Extase, but couldn’t travel, and it was badly affected by BYDV. That’s what he wants to avoid.

“Other growers who managed to stick to the BYDV programme had some humungous ruts to deal with, so it can be difficult. But in the deep south west Septoria is the key.

“There is a bit of a yield lag currently with BYDV-resistant varieties, but the AHDB do say treat the differences with caution. I always advise growers not to be wooed by high yield figures – management probably has a higher impact than variety choice ever will.”

Given the promising varieties in the Genserus pipeline, it is perhaps only a matter of time before they find real favour in Neil’s region. “We’d like to see the trait in a variety with really strong disease scores and top yields. That will be like going back to Deter days, only better,” says Neil.

“Resistance doesn’t run out of steam, so we’ll be able to plant the crop, pre-em it and shut the gate until spring, doing away with the need for pyrethroids and hopefully making life easier for everyone.”

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