At Ashton Farms in Wiltshire, Arable Manager Martin Smart (left) knows all about the importance of adaptability and finding the right oilseed rape variety. Overseeing a mix of farming, contract farming and share farming on awide variety of soils – which include Cotswold Brash, chalk, flint and heavy clay – he notes that it can be risky going with a new variety without first seeing how well it performs.
This means that he likes to be able to constantly assess the latest varieties, choosing them according to how they perform in his specific on-farm conditions. In order to achieve this, Mr Smart utilises oilseed rape trials, trying 16 varieties each year. Last year, Invigor 1035 was one such variety, but he explains that these trials are designed to test, not show off, the oilseed rape crop.
“We often drill them in unfavourable situations,” he says, noting that the InV1035 was drilled on 15th September, later than he would usually drill oilseed rape. “That’s what we want to look at: to see how varieties cope under pressure. It also means that you get a better look at the varieties’ characteristics, such as their vigour.
“If they perform in our on-farm trials, we know they are going to come up with the goods and we can then start incorporating them into our variety choice. That’s what happened with InV1035: it did well in our trials, establishing well and achieving a nice healthy colour, so we’ve now brought it into a bigger commercial block.”
Through this approach, Mr Smart grows a mix of stalwarts such as DK Extrovert or SY Harnas alongside new varieties. “You want varieties where you know exactly what they’re going to do each year. But I’m also trying to stay two years ahead of the game, and that means seeing what else suits me.”
Mr Smart employs a combination of hybrid and conventional oilseed rape. Further east, at Stody Estate in Norfolk, Mike Wilton is more unequivocal. Under his stewardship, the 240 hectares of oilseed rape grown on the farm has been 100% hybrid for eight years.
“You need to choose the varieties that best suit your farming system,” he says. “For where we are, hybrids are absolutely the right choice, for a few reasons. One reason is the vigour. Another is that we’re looking to access the best genetic material – whether that’s pod shatter, Phoma resistance, and so on – and that’s all coming down the hybrid stream.”
A vigorous variety is a central part of Mr Wilton’s strategy to withstand pigeon damage. With the estate surrounded by woodland, pigeons have ample cover, and have the potential to very quickly decimate a crop.
“We need our crops to grow away very quickly and be a decent size going into the winter, because we know we’re going to have pigeon problems. We also look to plant at quite low seed rates, sowing 40 seed/m² with the plough and looking to end up with 25-30 plants.”
This year, however, it was a different pest that challenged Mr Wilton’s hybrid oilseed rape. In Norfolk, flea beetle has historically been less of a problem than in other parts of the UK. But in this instance, he saw much higher pressure from the pest than in previous years.
“That was the highest pressure we had on any site from flea beetle,” he says. “The InV1035 was drilled quite early, for logistical reasons, and in a field that is in a slightly shorter oilseed rape rotation. Then after drilling, conditions became very dry, and we were left exposed to the beetle.
“The amount of damage did cause me some concern. But once conditions improved and we’d implemented an insecticide programme, the crop just grew away from the problem and never looked back. The vigour of InV1035 meant we ended up with a fully established crop that doesn’t appear to have been compromised by the difficult start.”
When it came to protecting against diseases, Mr Wilton used Proline (prothioconazole) as part of his fungicide programme. Historically, Phoma has been the biggest threat his oilseed rape has faced, but recently he has seen more light leaf spot. It was therefore important to choose a product with broad-spectrum control.
“We want to make sure we’re covered against as many eventualities as is practical and economical. We’ll use Proline once or twice in the autumn, depending on the Phoma risk, and then once again in the spring (or twice if we only went with one spray in the autumn). The timing of the spring spray, whether it’s just at early flowering or at mid-flowering as well, will depend on the Sclerotinia risk. So it’s about judging all the risks, and going with a solution that covers the majority of diseases.”
Thanks to this considered strategy, and the variety’s own vigour and resilience, InV1035’s power of recovery was evident when compared with other varieties in the field going into the new year.
“Most of the other varieties on the farm were in situations where they did not have the same shorter rotation and therefore they never had the pest pressure. But if I drove you round, and asked you to tell me which had had the pest problem early on, I’d defy you to be able to tell me. There’s no difference between that field of oilseed rape and any other field of oilseed rape I’ve got.”
Though situated on opposite sides of the country, Mr Smart and Mr Wilton have to confront pests, diseases and establishment issues familiar to most growers of oilseed rape. In both cases, they have found that vigorous hybrids play a crucial role in their respective growing strategies.