The potential of the potato has only just begun to be realized, writes Sandra Cordon in an article published by Landscape News. Sandra writes that some 368 million metric tons of potatoes were harvested globally in 2019, as people from Vietnam to Kenya, the Peruvian Andes to Rwanda produced a wide variety of the root vegetable, helping feed an estimated 1.3 billion people who rely on them as a staple food. In step, researchers around the world are hurrying to find ways to increase the quality and yield from potato production through targeted varieties better suited to local weather and soil conditions.
Pests and Diseases
Upcoming WPC webinar: Prof Jacquie Van Der Waals on diseases threatening sustainable potato production
The World Potato Congress is pleased to be beginning its Fall webinar series on November 12, 2020 with Professor Jacquie van der Waals from the University of Pretoria, South Africa. Professor van der Waals will present – “Above and Below Ground: Diseases threatening sustainable potato production”. This presentation will discuss three important disease complexes in potatoes, namely Rhizoctoniasis, soft rot and blackleg, early blight and brown spot. For each of these disease complexes, Prof van der Waals will introduce the pathogen, give a description of symptoms, discuss the disease cycle and touch on basic management principles.
Angus farmers are at the forefront of efforts to tackle the growing problem of potato cyst nematode (PCN) which is having a multi-million-pound impact on the Scottish industry every year. As chemical options are withdrawn from use, a group of producers and researchers have turned their attention to biocontrol methods, which include using a chitin-rich compost made from a substance that occurs naturally in shellfish.
As New Zealand Spring and Summer rolls towards potato growers, so too do the myriad of pest and disease management activities. One of the greatest challenges especially for growers, is the control of Potato Tuber Moth (PTM). Potatoes New Zealand’s recently completed PTM literature review looks at the various control approaches to this pest and suggests an integrated approach to PTM management. The review of scientific publications from the last 10 years on potato tuber moth research, focusses on several management options.
Widespread fungal disease in plants can be controlled with a commercially available chemical that has been primarily used in medicine until now. This discovery was made by scientists from Martin Luther University Halle-Wittenberg (MLU) and the University of the State of Paraná in Brazil. The team administered acetohydroxamic acid onto the plants, a substance also used to treat harmful bacteria in the human stomach, and which is known to inhibit the breakdown of urea. The acid was also found to be effective against numerous other pathogens which cause diseased plants, for example, late blight in potatoes.
Scientists in Kenya have reportedly developed potato varieties that are resistant to potato cyst nematodes (PCN) in what promises to change fortunes of farmers in the country and across Africa, according to a news report by Xinhua. The scientists from the International Institute of Tropical Agriculture (IITA) and the International Centre for Insect Physiology and Ecology (ICIPE) in a statement on Tuesday said besides resistance to PCN, the new varieties are early-maturing.
As if the beleaguered potato and its growers don’t have enough diseases to contend with, a new potato disease was discovered by Chinese researchers on potato plants during the growing season and also on tubers during the storage period. The disease was identified in potatoes cultivated in Nileke County, Qitai County as well as other locations in Xinjiang province in China. The pathogen was identified by the researchers as Galactomyces candidum F12, identified on the Atlantic potato variety.
In a recent collaboration between the Chinese Academy of Agricultural Sciences and the James Hutton institute, scientists identified a diploid wild potato with a high resistance to P. infestans, according to a press release issued by the American Phytopathological Society. “We found that the observed resistance in this wild potato was due to previously uncharacterized novel resistance genes,” explained Guangcun Li, one of the scientists involved in the study. “We also discovered that photosynthesis was inhibited to promote the immune response.”
This article was written by Canadian potato specialists, Dr Eugenia Banks (Ontario Potato Board) and Mark VanOostrum (WD Potato Ltd), and we publish it here with permission. They write: An essential requirement for a long storage period is that the storage conditions match the needs and the end use of the crop. The storage requirements of the crop can be assessed before harvest by doing several test digs which allow to determine – if present – the distribution and level of tuber infection. If there are risky areas in a field such as low spots that have blighted potatoes, skip those areas, do not harvest them.
Through the Innovative Farmers programme, four farmers located in Shropshire and Lancashire in the UK are looking at an alternative control method that uses plants known as trap crops that naturally ward off potato cyst nematodes (PCN). Trap crops are better described as ‘deceiving’ rather than ‘trapping’ plants. The chemicals released from the trap crop roots signal the presence of suitable food and trigger the nematodes to emerge from their safe hiding place in the cyst. The nematodes begin feeding on the trap plant roots instead of the potatoes, ahead of potato cropping.
With the Scottish seed potato harvest beginning a fortnight ahead of normal, SRUC consultant Dr Stuart Wale has reminded growers of the threat from dry rot, according to a news article published by Potato Review magazine. He recommends two fungicide options in this situation: Gavel (imazalil) and Storite Excel (thiabendazole) which can be used alone or in mixture. Dr Wale urged growers to have a conversation with their seed suppliers sooner rather than later to discuss treatment.
The latest Spud Scoop newsletter for the week ending on September 12, 2020 was published yesterday. Spud Scoop is a growing season publication compiled by specialists at NDSU Extension and University of Minnesota, combining information for potato growers. Contributors are Andy Robinson, Gary Secor, Ian MacRae and Julie Pasche. According to information contained in the newsletter, no late blight has been reported in potato fields in ND, MN and MB.
A University of Idaho-led team will tackle a pair of viruses that cause major losses to the potato industry. In a press release issued by the University, it is said that U of I researcher and potato virus expert Alex Karasev will lead the project funded by a $5.8 million grant from the U.S. Department of Agriculture National Institute for Food and Agriculture. The team of two dozen scientists will target potato virus Y (PVY) and potato mop top virus (PMTV) in seed potatoes, the first level of commercial potato production, and in potatoes grown for market.
Despite an increase of 60% in the area of cultivated land, production has been declining from an average of 20 tonnes a hectare to around 9.1 in Rwanda, 8.6 in Kenya and 4.3 in Uganda. This is way below the potential production of 40 tonnes a hectare. The factors contributing to the low and declining yields include losses due to attack by a range of pests and diseases. Potato cyst nematodes (PCN) are the most recent pest threat to emerge in the region. Targeting the nematode during hatching and just before it invades host roots, stands out as the most vulnerable life stage to target for their management.
Potato mop-top virus (PMTV) and tobacco rattle virus (TRV) are very different viruses, but the symptoms they cause are virtually identical. In this article, Carrie Huffman Wohleb – Associate Professor at Washington State University – takes a closer look at these viruses and suggests potential control strategies. “Spraing” is an old term used to describe the brown arcs, flecks, or rings in the flesh of tubers that result from potato mop-top or tobacco rattle infection. If you see these symptoms, it’s important to find out which virus you are dealing with, because their management strategies differ.
Potato blight has raised its ugly head in parts of the UK late in the season, following a spate of turbulent weather, Corteva Agriscience’s field technical manager for potatoes, Craig Chisholm, reportedly received a flurry of calls from growers and advisors on how to protect crops late in the season. Catchy weather may well extend the intervals between spraying blight fungicides, so we are advising growers to use a product that will protect the canopy for 10 days,” he advised.
Dr Sarah Sommer and her market research team is working on multiplexed potato virus lateral flow assays at the Newcastle University. The aim is to develop a simple but effective preventative disease testing kit that combines with a smart phone app. Sarah would like to know how the tool can be used in a practical environment and connect with interested potato industry people with whom she can discuss the concept, its further development and eventual application.
Potato growers in the UK are at risk of virus and disease threat if they do not follow an integrated approach to new desiccation regimes, say experts working on the third year of desiccation trials taking place across AHDB Farm Excellence sites. Results and observations at the trial sites have shown that the slower ‘kill’ achieved by the chemical and mechanical alternatives to diquat means that green stems and leaves can still be present up to three weeks after desiccation sprays. Even very small amounts of ‘green material’ remain a viable target for virus-carrying aphids and diseases.
Blackleg is one of the most damaging bacterial plant diseases in the UK, responsible for annual losses of £50m for the British potato industry. AHDB says in a news article published today that it is supporting and funding multiple projects researching this disease. A project which started three years ago, looking at how to achieve better control of blackleg, will be completed this summer, while another one which will also last for three year is just starting. A large project which was co-funded by AHDB & Scottish Government is due to finish this summer.
Scientists at CGIAR-IITA, working with the International Centre of Insect Physiology and Ecology (icipe) (under the joint Nematology Unit, NemAfrica, based in Nairobi), and their national and international partners have been at the forefront of efforts to address a new emerging pest threat to the production of potato in the East Africa region: potato cyst nematodes (PCN), These destructive pests can cause yield losses of up to 80%, and in some instances, even total crop failure, reports Kilimo News in a recent article.
Scientists at the James Hutton Institute and partner organisations are working to understand the interactions between the pathogen Pectobacterium atrosepticum and an array of soil-microbe-crop interactions in the development of blackleg, one of the most damaging bacterial plant diseases in the UK, responsible for annual losses of £50m for the potato industry. The issue is at the heart of a £2m research project funded by the Biotechnology and Biological Sciences Research Council (BBSRC), Natural Environment Research Council (NERC), Defra and Scottish Government.
A new online tool aiming to improve accuracy of slug pellet applications is now available, allowing operators to effectively set up uniform and precise pellet doses, according to a news story published by Farmers Weekly in the UK today. The app, named Calibration Wizard, which has been developed by slug pellet manufacturer Certis, in partnership with SCS Spreader and Sprayer Testing, hopes to reduce labour time calibrating equipment.