Robert Lindley Ltd limited grows about 200ha of potato seed across the country from its base at Burton Fleming, East Yorkshire, which is sold retail to its customer base.
Since the shock of 2018, where aphid levels where high and the depleted insecticide armoury left crops exposed, managing director Ed Lindley has had to rethink his approach to seed production.
The stakes are high. Any downgrading of seed stocks makes a significant dent in profit, as production costs increase and agrochemical protocols for seed and ware production diverge, making dual purpose crops almost impossible.
Reducing this risk has been a priority for Ed and varietal susceptibility is an increasingly important consideration when planning for a new season.
He grows for two seed houses – Meijer and HZPC – and of their varieties Melody, Orchestra and Sagitta present the lowest virus risk so are now the mainstay of his seed production.
Conversely, some high-risk varieties have been dropped and those that remain are never grown for more than one year in Yorkshire, where the proximity of ware and seed production heightens transmission risk.
“You have to try to grow the varieties that the market demands, but those that really do get a lot of virus just aren’t worth the risk.
“I daren’t double multiply, as it’s not worth the gamble either. Some of our high-grade production has been moved further south [where potato production is less intense] to further reduce risk,” he adds.
In the field, he delays planting of seed crops where possible to avoid them emerging into the first major aphid flight which typically comes in mid-May but can vary depending on several factors, particularly the previous winter’s weather.
Once crops emerge Ed concedes that options are increasingly limited following product withdrawals and the decline in efficacy of pyrethroid insecticides.
But with the relatively high virus risk in the Yorkshire due to intense ware cropping largely not receiving insecticides, he is prepared to use all options available to protect his seed crops.
While there is still a lot to learn on mineral oil use in the UK, evidence from Europe and limited research here suggests it can help reduce transmission of non-persistent virus in the early stages of crop development.
Ed typically starts off his programme with four applications of mineral oil on five-day intervals and adds in the available systemic products once colonising aphids begin moving into crops.
Applications then continue in accordance with product labels to ensure crops are protected for as long as possible through the growing season.
Summary – how Yorkshire seed potato growers are reducing virus risk
Read the first case study in the series here.