Potato Review

www.potatoreview.com POTATO REVIEW JANUARY/FEBRUARY 2021 23 BIOSTIMULANTS W EATHER trends show a clear shift to higher temperatures, including prolonged periods of excessive peaks. And it’s crops with shorter growing seasons that can least a ord any interruption in peak photosynthetic activity as a result of stress, warns Dave King, Head of Technical at Syngenta. “Heat typi es the increasing stress potato crops are having to cope with. But there are a whole range of other abiotic in uences adding increasing pressure, including drought, nutrition, solar radiation and air quality. at’s where we have seen biostimulants have a valuable role to play in mitigating the e ects of stress,” he said. “ e greater the apparent in uence of stress in limiting the crop’s potential, the higher the yield response recorded.” Having completed eld trials of a UK study of biostimulant use in potatoes, Dave saidd initial analysis showed a correlation between Biostimulant interest hots up Biostimulants are set to become a hot topic in all UK crop production, with potatoes among those with the most potential to gain. the high temperatures experienced earlier in the season, and potential for yield responses where crops had been a ected. Using heat as an example of the increasing in uence of abiotic stress on crop production, he highlights the latest Met O ce State of the Climate report shows the UK is experiencing higher maximum temperatures and longer warm spells. All of the top 10 warmest years since records began in 1884, have occurred since 2002. Furthermore, hot summers are expected to become more common. De ned hot spells have increased from an average six days in length during records from 1961-1990, to more than 18 days per year on average during the most recent decade. e chance of experiencing summer temperatures as hot as any previous record years is now set at an unprecedented 12-25%. Research has shown the optimum root growth in potatoes occurs at soil temperatures of 15 to 20 C, with a fall o when temperatures exceed 20 C. e relatively shallow rooting of potatoes in the top 60cm of soil pro le, compared to cereals rooting to at least twice that depth, makes the crop more susceptible to temperature changes. Furthermore, conditions for both haulm and stolon growth peak at around 25 C. Warmer soils have also been shown to limit tuber initiation and the numbers of tubers formed. e UK’s highest temperature of 38.7 C, recorded in the eastern counties in 2019, exempli es future challenges for potato production. Biotic targets and abiotic elements Speaking at the AHDB agronomists’ conference, independent biostimulant expert, Rob Cannings of Agri-Future Consultants, outlined where biostimulants sit in the hierarchy of products ➜