Potato Review

34 POTATO REVIEW JANUARY/FEBRUARY 2020 AGRONOMIST CONFERENCE C lose cooperation between government, agriculture and researchers drove growers to rapidly adopt PCN (Potato Cyst Nematode)-resistant potato varieties following an environmental crisis in the Netherlands. Delegates at AHBD’s Agronomist Conference heard how the popularity of a particular variety among Dutch growers led to pollution of drinking water: The variety – Bintje – was widely used in the Netherlands in the early 20th century despite having no resistance to PCN. This prompted growers to rely heavily on chemical fumigant nematicides that leached into the water supply. Following a sustained campaign by environmental groups, including Greenpeace, and the increased availability of varieties resistant to Globodera pallida, breeders were able to move away from Bintje. The presentation, by Leendert Molendijk, Senior Nematologist at Wageningen Research was one of two speeches highlighting the importance of varietal selection as a part of Integrated Pest Management (IPM); showing agronomists how growers can combat pests and diseases with a rapidly shrinking chemical toolkit. Following Leendart, Graeme Byers of British crisp and snack manufacturer Tayto Group said he was confident the UK potato industry could wean itself off common varieties and adopt those with better resistance. Graeme called for greater cooperation between breeders and processors to enable larger scale processing trials of new varieties earlier in the breeding process. Holistic approach With the removal of diquat spurring the search for alternative desiccation methods, Eric Anderson of Scottish Agronomy explained a more holistic approach was required. He said that while both mechanical plus chemical and chemical solutions needed development, compression damage to ridges in wet conditions showed how flailing had its limits. Both Eric and Dr Mark Stalham of NIAB presented data from AHDB funded experiments showing haulm desiccation and skin set don’t correlate well: in separate trials each found that a treatment with pelargonic acid triggered skin set even though it had a weak effect on foliar desiccation. Dr Stalham’s work showed that Saltex (brine) helped open up canopies and was associated with good skin set in vigorous canopies. He found no significant differences between the previous standard, Reglone, and flailing with chemical or chemical only treatments. Delegates also heard from Dr David Cooke of the James Hutton Institute who updated on AHDB’s ‘Fight Against Blight’ service. Overall 2019 saw mixed fortunes for growers with periods of both low and high risk. Wet weather in spring and summer provided challenging conditions and samples of blight were sent in from 229 outbreaks from which nearly 1,000 samples were genotyped. Europe wide data from Euroblight showed instances of ‘new genotypes’ 36_A2, 37_A2 and 41_A2 rose from 10% - 36% of the population, whilst the ‘old genotypes’ 6_A1, 13_A2 and 1_A1 fell from 60% to 40%. The new clones mean increased pressures for growers’ blight management strategies and Dr Cooke warned that mistakes could be costly. Lessons for British growers from Dutch experience The presentations made up the second day of AHDB’s annual Agronomist Conference: catering to agronomists working with potato growers and providing the latest research on IPM. With over 100 delegates, the Agronomist Conference is one of the levy board’s high profile events. Next year’s Agronomist Conference will take place on December 1st and 2nd, 2020. David Cooke Graeme Byers Leendert Mark Stalham