Potato Review

4 POTATO REVIEW NOVEMBER/DECEMBER 2019 NEWS Editor Stephanie Cornwall 01778 395055 stephanie.cornwall@warnersgroup.co.uk Multimedia Sales Executive eresa Geeson 01778 392046 theresag@warnersgroup.co.uk Publisher Juliet Loiselle 01778 391067 Julietl@warnersgroup.co.uk Design Dean Cole deanc@warnersgroup.co.uk Subscriptions 01778 392464 subscriptions@warnersgroup.co.uk Subscriptions & advertising copy Potato Review, Warners Group Publications, e Maltings, West Street, Bourne, PE10 9PH www.potatoreview.com ISSN 0961–7655 © AREMI Ltd 2019 e publishers are not necessarily in agreement with opinions expressed in this journal. No responsibility can be accepted for statements made by contributors or advertisers. POTATO REVIEW is published by: Warners Group Publications, e Maltings, West Street, Bourne, PE10 9PH Printed by Warners (Midlands) Plc Manor Lane, Bourne, Lincs. PE10 9PH November/December 2019 PRINTED BY WARNERS 01778 395111 The Maximum Residue Limit (MRL) for pencycuron is currently under review by EFSA, in a process that started in 2011. In December 2018 EFSA published its Reasoned Opinion (RO) on pencycuron MRL and proposed to revoke the MRL on potatoes and vegetable crops, which would mean the registrations on these crops being withdrawn. Bayer subsequently submitted new data to defend its use on potato crops, which should be reviewed by regulatory authorities before any final decision is made. The firm’s campaign manager for root crops, Edward Hagues (left), said the decision to suspend sales of Monceren DS was not one the company took lightly, but on the possibility that a withdrawal of registration could a’ect next year’s crops. Bayer has suggested using its Emesto Prime (penflufen) as an alternative. “Monceren has an e’ective and trusted product for decades, but consideration of the probable decision meant there was little option but to suspend sales until the situation is clarified,” Ed said. “Fortunately, Emesto Prime DS o’ers greater protection so growers can be reassured tuber quality and marketable yields will not be compromised.” Even if revocation of the active ingredient pencycuron occurs, the likely scenario would mean crops would need to be treated by April 2020, and importantly, all harvested potatoes sold by October 2020, Sales of Monceren suspended by Bayer otherwise they risk being in contravention of a new MRL. “Given this unclear situation and the potential consequences for potato growers of using a product that could potentially mean concerns selling the harvested crop, being a responsible company, Bayer has decided to stop sales of pencycuron containing products,” a company statement revealed. It has also recommended distributors and agronomists advise growers to stop using the product until it receives the final decision of authorities on the MRL value. “If the company receives favourable news regarding the MRL, it will resume sales of pencycuron containing products,” the statement continued. Although slightly more expensive, Bayer’s Emesto Prime (penflufen) has been shown to increase yields and minimise the risk of Rhizoctonia solani attack. Ed stressed that the product has “substantial positive e’ects” on black scurf incidence on tubers, crop emergence, final stand, tuber size distribution and marketable yield, and referenced a trial performed at Fife by Scottish Agronomy last year. “The trial used heavily infected seed with tubers from the untreated crop su’ering a 47% incidence of black scurf. Tubers from the Emesto-treated crops were found to contain no detectable levels of black scurf,” he said. High levels of Rhizoctonia infection in fields with repeated potato rotations, combined with an increasing nematode population, risks hitting emerging crops, and a’ecting plants right through to tuber quality at harvest, warns Gus Merrick of Syngenta. Gus reported potato consultants’ views that nematode feeding damage on root stolons allows the soil-borne Rhizoctonia pathogen to get into plants more easily, with infection resulting in stem and stolon pruning that delays emergence. “If growth is further delayed by wet or cold soils, the e’ects can be severe,” Gus (left) advised. “However, Rhizoctonia is a relatively weak pathogen that can be e’ectively controlled in the soil. “Patchy emergence has serious implications for crop management,” he added. “Whilst the canopy appears to recover over the season, it inevitably has ➜ ‘Protect roots for even potato emergence’ Bayer has decided to stop sales of the potato seed treatment Monceren (pencycuron) with immediate e’ect owing to the uncertain regulatory future of the product, and the potential consequences for potato crops treated with it.