Official output ratings are not something Scottish Borders grower, David Fuller-Shapcott of Sweethope Farm just outside Kelso considers important in his OSR variety selection. Yet he has brought in good 5t/ha-plus farm averages in the past and, at 4.9t/ha, his 2018 YEN crop of DK Exclaim was within the top third of entries for percentage of estimated yield potential.
Instead he looks for high oil content, strong phoma and light leaf spot resistance, stem strength and pod shatter resistance in his varieties because he knows the most reliable performance invariably follows-on from these genetic essentials. He also prioritises varieties that suit his decidedly challenging soil conditions and particular growing regime.
“Rape always does best at low seed rates,” says David. “The last thing we want is mustard and cress. We’re after plants that are big and bushy rather than tall and tree-like. These give good light-intercepting canopies that don’t need much growth regulation.
“Hybrids like DK Expansion and DK Exclaim which are very vigorous but don’t take-off too early in the spring before our ground warms-up enough to provide the nutrition they need suit us well. These are important things that RL testing simply doesn’t tell us about.”