The top-yielding OSR variety on the Recommended List can help growers manage their risk next season, as it is the first one with tolerance to a disease that in severe cases can halve yields.
PT303 from Corteva tops the current UK Recommended List with a gross output of 107%, through its high yield and good agronomics.
But what makes the variety even more attractive is that it can help growers manage the risk of sclerotinia, the first UK variety with tolerance to the disease.
Speaking at the Cereals event, Corteva’s seeds and inoculants manager, Andy Stainthorpe, said the variety tops the list based on its high yield and agronomics and this wasn’t achieved because of the disease tolerance.
That’s because all Recommended List plots receive flowering fungicides, even the untreated ones. So the benefit from the disease tolerance is on top of its Recommended List trial yield, he said.
Mr Stainthorpe explained the tolerance comes from two sources – genetics, plus the lower humidity under the canopy as the plant structure allows better airflow. High humidity is conducive to the disease.
Trials carried out by the breeder show that when sclerotinia infection levels are 25% or above the severity of the disease in PT303 is reduced by up to 75%.
He sees the variety being used to manage risk in two senarios: Growers may decide to continue with their planned fungicide programme and use the tolerance as an insurance against getting the fungicide timing wrong.
Or, if a grower believes the risk to be low, the weather is dry and there is no history of the disease, they may knock out a spray and save on their fungicide spend.
Growers can also buy seed treated with Lumiposa, adding further protection. This is the only insecticidal seed treatment currently approved for use on oilseed rape seed, he said.
Containing the active cyantraniliprole, it offers some help to establish a crop in the face of attack from different pests, including cabbage root fly and cabbage stem flea beetle.