Wheat varieties with resistance to barley yellow dwarf virus have delivered outstanding control of the disease and have gone on to produce exceptional yields, according to latest RAGT trial results.

The fully replicated trials tested several RAGT varieties containing the Bdv2 resistance gene and a range of widely grown commercial varieties under the toughest conditions.

Plots were sown in early September 2020 and inoculated with virus-laden aphids, four times in the autumn and four times in the spring. No aphicide was used.

Plots were scored weekly for disease symptoms from mid-April to produce a visual assessment score (see graph).

Tom Dummett, RAGT’s cereal and OSR product manager, says: “The Bdv2 material, which included RGT Wolverine, Europe’s first winter wheat with resistance to BYDV, and three pipeline varieties, showed no symptoms, apart from a few isolated traces of yellowing, which can occur under high pressure.

“All the commercial winter wheats exhibited severe symptoms, including multiple infection sites, multiple red leaves and stunted growth – up to 50% in the worst cases.”

Pre-harvest viral load assessments backed up the visual scores. No detectable viral load was found across the RGT Wolverine plots, but both the commercial varieties tested contained a high viral load.

All plots were taken to yield. Two of RAGT’s pipeline feed varieties, RW42046 and RW42047, currently in NL1 trials, took first and second place respectively, producing yield equivalents around 10.5t/ha (see graph).

RGT Wolverine came third, at 10t.1t/ha, nudging ahead of its nearest conventional competitor and leaving other feed types struggling at 8.8 to 9.2t/ha.

The picture was repeated among the quality wheats. RAGT’s coded variety 20E0S303, which has breadmaking potential, produced a yield equivalent of 9.3t/ha, 0.25t/ha ahead of Extase and over 1t/ha ahead of Siskin.

The results reinforce last year’s findings when eight out of 10 popular conventional varieties yielded between 5% and 18% less than the Bdv2 lines, none of which lost yield. 

A further trial examining a range of wheats, each split into two near-isogenic lines, one with the Bdv2 gene and one without, confirmed the gene’s effectiveness. 

The yield advantage of the Bdv2 lines ranged from 0.97 to 2.18t/ha and averaged 1.57t/ha. 

“Anyone sowing wheat early this autumn in a BYDV-prone area should seriously consider growing RGT Wolverine to manage risk,” says Mr Dummett.

“RGT Wolverine is now widely available and is among the highest yielding varieties on the Recommended List, so it will deliver excellent returns even in the absence of BYDV.”