UK: First SDHI fungicide to control Rhizoctonia said to offer 20% more yield

In-furrow applicationThe first in-furrow SDHI fungicide for potatoes offers farmers another option for controlling Black scurf, caused by the fungus Rhizoctonia solani, a disease that can slash marketable yields by 30%. (SDHI stands for Succinate DeHydrogenase Inhibitors in the UK). Although growers can successfully control the disease with azoxystrobin, it can prove harsh on plants leading to delayed emergence. However, from next season growers will have an alternative that is less harsh, said Basf campaign manager Matthew Goodson at the recent British Potato event in Harrogate. Based on the SDHI active fluxapyroxad, the new potato product Allstar outperformed the in-furrow strobilurin in independent German trials. “Allstar yielded 20% more potatoes than azoxystrobin [treated crops] across all six varieties tested.” More

British Potato 2017: Latest technical updates from potato event

The latest potato agronomic developments were showcased and industry concerns aired at BP2017, held in Harrogate, North Yorks. More data is needed to assess and respond to the threat posed by the Dark Green 37 blight strain, which has shown resistance to fluazinam. David Nelson, field director, Branston said more understanding of the Dark Green 37 strain was needed. “It is the biggest challenge in blight control since metalaxyl resistance in the 1980s. We don’t understand it really and need to collect information in the next 12 months. We need a lot more blight scouts. Loss of glyphosate could limit land availability for growing potatoes, warned Paul Colman, technical director, Greenvale AP. “It is a critical herbicide for controlling volunteer potatoes. Landowners renting out land may make the decision they don’t want potatoes in the rotation anymore.” BASF has launched an SDHI fungicide, Allstar (fluxapyroxad) for control of rhizoctonia in potatoes. Continue reading

Netherlands: Agrico claims “double the yield with resistant organic potato varieties”

“Within three years, we want to fill at least half of our planted area with resistant potatoes,” says Peter Dijk on behalf of Agrico. The potato breeding company from Emmeloord, the Netherlands, currently grows organic consumption potatoes on a total of 500 hectares. “Potato varieties resistant to the potato disease Phytophthora are growing on an ever-increasing surface.” Regarding yields, Agrico is very satisfied about these varieties: “If the fungus shows up early in the season, it doesn’t make much difference if there’s a resistant or non-resistant variety on the field. If the fungus shows up late in the season, the resistant variety scores very high so far. With resistant varieties, we even realise a double yield sometimes. …We have to realise a more acceptable price level for resistant organic potatoes. A higher yield is necessary for that. We have the resistant varieties, but now growers have to start profiting from them.” More

US: Potato researchers gather to find solutions for the blackleg disease

Potato researchers gather in Maine to find a solutions for the Blackleg diseaseResearchers from all over the world were in Bangor, Maine for the ‘2017 Dickeya and Pectobacterium Summit’, organized by the University of Maine Extension. They are trying to find a way to stop the blackleg potato disease that could threaten the potato industry. According to Steven Johnson, UMaine cooperative extension professor: “This is not an emerging problem. This is an existing one we are trying to get ahead of. The pathogen may rot the tubers in the field. It may produce 20 to 80 percent less yield in the field. It may rot the potatoes in storage.” Maine’s potato crop brings a lot of money to the state and provides a livelihood for many growers. All of that could be threatened because of bacteria that causes blackleg disease. It isn’t just Maine that is impacted. The disease is hitting the potato industry worldwide. Researchers from 19 states and four different countries attended the meeting trying to find solutions. More

Ireland: Is the wild potato the key to less fungicide use on spuds?

potatoScience week in Teagasc Oakpark has opened up students minds to the humble spud and the wild potato continued to come up in conversation. Why? The answer is simply potato blight, as the wild potatoes found in South America are resistant to blight. Some of these potatoes might not be as tasty or suitable for the supermarket, but they have one very important quality – they aren’t susceptible to blight. Oakpark is the home of potato breeding in Ireland and while it has successfully bred many different breeds, potato blight remains the big threat to the industry. Denis Griffin, a Teagasc research officer with Teagasc , stated: “One of the big pressure points for potatoes is still late blight. We have to spray the susceptible varieties 12-15 times. …One of our major goals over the next few years is to try and introduce resistant genes from wild species for late blight and reduce the amount of pesticides we have to use.” More

New tools for growers to be launched at British Potato 2017

British Potato 2017 is an occasion for launching and introducing working tools for growers. The event takes place in Yorkshire Event Center, Great Yorkshire Showground, Harrogate, UK, during November 22-23. For example, Fera, an international center for interdisciplinary in investigation and problem solving across plant and bee health, will present a new in-field diagnostic tool for potato nematodes. On the other hand, AHDB Potatoes will launch a tool which allows growers and those in the supply chain to examine data on price, variety, planted area, market sector and yield. Senior nematologist Tom Prior will discuss Fera’s new in-field diagnostic tool, scheduled to be launched in 2018, which is able to rapidly identify root-knot nematodes from plant material, in addition to soil analysis service. AHDB Potatoes will launch Potato Data Center (PDC) at BP2017. The tool allows growers and those in the supply chain to examine data on price, variety, planted area, market sector and yield. More

Potato diseases: War and peace, Verticillium style

Insights into the complex relationship between potato plants and this pathogen are helping to advance development of resistance cultivars. Verticillium dahliae, a soil-borne fungus, causes wilt, yellowing, necrosis and early dying in potato. This yield-robbing pathogen is tough to manage, has a broad host range, and is known to survive in the soil for up to about five years. Potato cultivars with improved resistance to Verticillium would be a great tool for growers. Now, Canadian research into the complicated interactions between potato plants and this pathogen has come up with a more effective way to select for Verticillium-resistant cultivars. Dr. Helen Tai, a research scientist with Agriculture and Agri-Food Canada (AAFC) who is leading this research, Tai and her colleagues have been getting down to the nuts and bolts – the genes and genomics – of exactly what is happening in Verticillium dahliae-induced early dying. “We called this ‘War and Peace’ genetic mapping to represent the two kinds of relationships between the plant and the pathogen.” Overall, her research has the potential to contribute to the development of better tools for growers to manage Verticillium wilt and potato early dying. More

UK: Early success for blight-resistant GM potato trial

Scientists inspect potato trial plotsA genetically modified potato variety designed to resist the devastating plant disease blight has successfully come through the first year of trials, say scientists. Worldwide, crop losses because of blight are estimated to be in excess of £3.5bn. However, scientists at The Sainsbury Laboratory (TSL) on the Norwich Research Park are trialling a Maris Piper potato that has been modified with blight resistance genes from a wild potato relative. “The first year of the Maris Piper trial has worked brilliantly,” said Jonathan Jones, a professor and project leader at TSL. “We’ve observed resistance to late blight in all the lines.” Prof Jones said early results suggested blight-resistant potatoes could be a way to control late blight and remove the need for multiple sprays of agrochemicals. More

Zebra chip pathogen found in Western Canada for the first time

Image result for zebra chip imageFor the first time, evidence of the zebra chip pathogen has been found in potato fields in southern Alberta, but the University of Lethbridge’s Dr. Dan Johnson cautions against panic. “So far, the zebra chip pathogen has appeared in only small numbers of potato psyllids,” says Johnson, a bio-geography professor and coordinator of the Canadian Potato Psyllid and Zebra Chip Monitoring Network. “The number of potato psyllids in all Alberta sites is very low and many sample cards have found no evidence of the potato psyllid insect. Zebra chip does not normally become a problem unless the potato psyllids are found in much higher numbers than are currently being found in Canada.” An infected potato psyllid insect carries the Lso (Candidatus Liberibacter solanacearum) pathogen that can cause zebra chip disease in potato crops. Zebra chip has affected potato crops in the United States, Mexico and New Zealand and caused millions of dollars in losses. Potatoes with zebra chip develop unsightly dark lines when fried, making affected potatoes unsellable. More

Potato diseases remain for Western Australia crop

Image result for Dickeya dianthicola potatoThe blight of the WA potato industry is worse than originally reported and it is unclear how and when things will improve now that WA farmers will have to live with the tomato potato psyllid (TPP) and Dickeya dianthicola bacteria. The Department of Primary Industries and Regional Development (DPIRD) confirmed last week that five properties in the potato-growing areas north and south of Perth have had quarantines lifted after extensive work in tracing the origins of the Dickeya dianthicola bacteria. The bacteria was detected for the first time in June in a potato crop north of Perth, prompting an immediate biosecurity response. Dickeya dianthicola can cause blackleg and soft rot diseases in potatoes and affect other horticultural crops. DPIRD had developed a rapid and high-throughput PCR test for Dickeya dianthicola – the first of its kind to be used in Australia. More

NZ potato and tomato growers relieved at the release of pest eating wasp

A pest which has cost the New Zealand potato industry over $120 million since 2006 may be on the way out thanks to a wasp which has been released in Hawke’s Bay and Canterbury. The tamarixia trioaze, a wasp that comes from the United States and Mexico, destroys the tomato potato psyllid pest by laying an egg on the psyllid. The wasp eggs hatch and the larvae feed on the TPP. Eventually, the larvae will chew a hole through the TPP’s shell to emerge as an adult. Vegetable Research and Innovation Board coordinator Sally Anderson said the arrival of the wasp was a relief for greenhouse growers. More

US: Spud breeders focus on PCN-resistant russets

John O’Connell/Capital Press
Rich Novy, right, a potato breeder with USDA’s Agricultural Research Service in Aberdeen, Idaho, saves breeding clones crossed from an Irish parent with late blight resistance while evaluating more than 100,000 first-year “single hill” clones Sept. 28 in trials hosted in Aberdeen.A project underway in Aberdeen, Idaho, aims to develop russet potatoes with resistance to pale cyst nematode, while identifying new molecular markers associated with resistance. Researchers with the local potato breeding program harvested a special block of first-year clones on Sept. 29, screened for their ability to help the industry cope with potato cyst nematode. The block contained a half dozen plants from each of 223 breeding clones resulting from crosses of Western Russet and Eden, a round Scottish variety with known resistance to potato cyst nematode. Joe Kuhl, a University of Idaho associate professor of plant genetics, will also use clones from the plot in genetic mapping research to identify new genes associated with PCN resistance. Kuhl said he’s midway through a five-year project focused on breeding PCN-resistant russets, funded by USDA’s National Institute of Food and Agriculture. More

Mexico: Zebra Chip-tolerant potatoes for the fresh market identified

Over the past few years, the potato production of US, Mexico, New Zealand and Central America has been under threat by Zebra Chip (ZC), a disease associated with the Candidatus Liberibacter solanacearum bacteria, vectored by the potato psyllid (Bactericera cockerelli). The disease turns part of the amide in soluble sugars so, when potatoes are cooked, sugars caramelise and streaks appear. Of course ZC is currently monitored with pesticides, but sustainable defence requires the development of resistant and/or tolerant varieties. Entomologists from the University of California Riverside, together with researchers from INIFAP (Mexico), characterised four promising potato lines (246, 865, 510, NAU) exposed to Cls-positive adult psyllids and monitored the vector’s behaviour towards the plants and the effects of the bacteria on the tubers. The potato lines were compared to ZC-susceptible variety Atlantic. More

Bio-sector in the Netherlands band together in effort to find sustainable solution for potato late blight

In the Netherlands, Aldi and Lidl recently signed a covenant titled ‘Accelerated transition towards resistant/robust potato varieties’. Signees also include Albert Heijn and Jumbo Supermarkets. Superunie, the purchasing organization representing thirteen independent supermarket organizations in the Netherlands, intends to sign the covenant shortly. Potato seed companies who signed the covenant include Agrico, HZPC, C. Meijer, Plantera, Den Hartigh, Europlant, Danespo, Caithness Potatoes and Plantum. With this agreement, the biological sector wants to provide a sustainable response to the feared potato disease, late blight. Continue reading

Webcast: Management practices for corky ringspot

Image result for corky ring spot potatoThe Plant Management Network has released a presentation by Michigan State University professor of nematology, George W. Bird, on management practices for corky ringspot This is a disease caused by the tobacco rattle virus and vectored by stubby-root nematodes. Usual symptoms are concentric rings on tuber skin and internal flesh. Bird’s presentation is designed to assist growers in all potato growing regions, in understanding and managing corky ringspot. The presentation contains information about the typical symptoms of the disease, and how growers can sample for the stubby root nematode. It further covers management strategies of containment, exclusion and nematode population control. Special attention is also given to chemical and biological control options, and the topic of soil health. More