UK: Guidance on reduced fluazinam sensitivity in late blight populations

Image result for late blight ahdbIn July 2017, AHDB in the UK notified its blight network about reports of the spread of EU_37_A2, a strain of blight first discovered in the Netherlands in 2013 which has shown reduced sensitivity to Fluazinam, a common fungicide used to tackle blight and other diseases. As a result, you can find the two below links to guidelines on how the potato industry should respond to reduced fluazinam sensitivity in late blight populations, which derives from research funded by the AHDB and carried about by SRUC and ADAS. For a full report please use the following – Guidance on how the potato industry should respond to reduced fluazinam sensitivity in late blight populations​. For a summary of the report please use the following – Guidance on reduced fluazinam sensitivity in late blight populations: summary

Black dot a particular scourge of fresh market potato crops in GB this season

Black dot has been a particular scourge of fresh market crops this season, according AHDB Potatoes in the UK. Delayed harvesting has encouraged disease spread, increasing the crop’s exposure to infected soil and high levels of moisture. Here’s a reminder of why the problem has been so widespread. Black dot is a disease caused by Colletotrichum coccodes. There is evidence that microsclerotia (resting bodies) of the fungus can survive for many years in soil due, in part, to alternate hosts. It can infect weeds such as nettle, field bindweed and shepherd’s purse.  Survival is further enhanced by the presence of potato volunteers. Black dot can be both seed and soil-borne. Although seed-borne infection can cause disease in progeny tubers, soil inoculum poses a greater threat. Soil contamination is the main source of disease in a progeny crop. Disease risk should be based on evaluation of seed infection and, importantly, soil contamination for which a soil test is available. Black dot is commonly confused with silver scurf (Helminthosporium solani). More in the latest Storage Bulletin from AHDB

Weed control goes digital: Advanced spot-spraying precision technology in development

Weed scientist Andrew McKenzie-Gopsill with digital camera, sensor and controller mechanism that can be  mounted on a sprayer and tractor to read crop plant locations.Researchers are combining new digital tools, computer technologies and machine learning to bring cost-effective weed control solutions to the field. This weed control solution is being designed as an advanced spot-spraying precision technology that will help farmers reduce input costs and add another management tool to their integrated management systems. “We are developing a high-tech ground-based sensor technology as another cost-effective precision agriculture tool for weed control in potatoes and other crops,” says Andrew McKenzie-Gopsill, weed scientist with Agriculture and Agri-Food Canada (AAFC) in Prince Edward Island. This five-year project was initiated in 2017 and is still in the early stages of data collection. The whole control system would be mounted to an existing sprayer, including a small inexpensive camera mounted above the canopy, and a mini computer to connect to the sprayer control system to control which nozzles are turned on or off. More

US: Grower due diligence important in control of newly emerged potato blackleg pathogen

A new blackleg pathogen, Dickeya dianthicola, emerged in the eastern U.S. in 2015. Since then researchers have been working to find ways to control the disease, as it causes significant yield loss in potato crops. While progress in terms of control methods has been slow, growers who have adapted suggested best management practices have contributed to the disease’s decline. While the disease’s decline could be attributed to weather conditions, which were mostly unfavorable to the its development, Gary Secor, professor of plant pathology at North Dakota State University, attributes the drop-off to seed lot testing and growers’ due diligence. “It is a bacterial disease, so we don’t have any really good chemicals that we can use to manage dickeya,” Secor said. Antibiotics were proposed as a possible solution, but Amy Charkowski, head of bioagricultural science and pest management at Colorado State University, says they’re really not an option since they’re very costly. More

Late sown potato crops could be vulnerable to blight

Related imageThe potato blight season has got underway in Great Britain with blight found on dumps in Kent. While such reports are not unusual at this time of year, it is important to be aware of the infection risk posed by cull potato piles, volunteers and solanaceous weeds, says Dr David Cooke of the James Hutton Institute. “Last year we had very early reports then it dried up and blight did not get started until July. But if it continues to be wet until planting, inoculum could stay active and that would be an issue.” Potato agronomist John Sarup says monitoring crops will be particularly important. He adds. “Start early and keep up with spraying. Start with something with early kickback containing cymoxanil. I would not be recommending fluazinam. More

Potato growers warned that new late blight strain requires fresh approach to control

Image result for New Blight Strain Requires Fresh Approach to ControlBlight control strategies will have to change this season if potato growers are to combat the spread of a new aggressive, fungicide-insensitive/ resistant strain of the disease, leading agronomy firm Hutchinsons in the UK says. The dark green 37_A2 form of Phytopthora infestans has quickly spread across Europe, reaching England two years ago when five cases were reported. Around 20 cases were officially recorded in 2017, mainly in the West Midlands, Yorkshire and Kent, and more recently in Suffolk, but Hutchinsons root crop technical manager Darryl Shailes believes the actual figure could be higher and all crops no matter where they are grown are potentially at risk. The new strain is at least, if not more, aggressive than the dominant blue 13 and pink 6, but the crucial difference is that it appears equally aggressive on foliar and tuber blight, he warns. More

Spore sampling project to alert growers of disease threat

A University of Idaho-led research team plans to start giving their state’s potato growers advanced warnings this season about the arrival of fungal pathogens, using a broad network of airborne spore samplers. Last summer, James Woodhall, the project’s lead and a University of Idaho (UI) assistant professor of plant pathology, and his colleagues evaluated samples collected by three spore samplers, based at their Parma, Kimberly and Aberdeen Extension centers, to prove the concept. This growing season, Woodhall said they’ll operate 14 samplers, stationed both at the UI facilities and near commercial potato fields spread from Parma through Tetonia. Woodhall intends to alert growers – initially via an email list and eventually by posting results on a special website – within a day of confirming the arrival of harmful potato pathogens including late blight, early blight, white mold, gray mold and brown spot. “It’s proven technology,” Woodhall said. “They’ve had success with this in Canada for late blight detection.” More

Factsheet: Best management practices to minimize the spread of PVY

Related imageThis factsheet is based on recent research done in Canada by Dr. Mathuresh Singh and his team in New Brunswick on PVY, which just concluded in March.  This research has been very successful in identifying which production practices are most associated with reducing the spread of PVY.  At the same time, PVY post-harvest test results in New Brunswick and Prince Edward Island have improved significantly in recent years, as these best practices are being more widely adopted. The factsheet was compiled by Ryan Barrett, Research & Agronomy Coordinator at the Prince Edward Island Potato Board, and published on the website. The document can be accessed here as a pdf file.

British potato growers can now sign up for new BlightCast alert service

Image result for blightcastPotato farmers in the UK can now sign up for the new BlightCast service to receive advance warning of Blight in their area via a five-day email report. With the Syngenta BlightCast agronomy tool, potato growers and agronomists will be better prepared to cope with more aggressive blight strains this season. It includes two prediction models: one for conventional Smith Periods and a forecast using the Hutton Criteria proposed to model strains of blight capable of developing at shorter periods of 90% relative humidity. BlightCast uses local weather forecasts and sophisticated disease modelling algorithms to predict blight risk for up to five days ahead – enabling growers and agronomists to plan strategies more effectively. Visit this page for details

Canadian breeder brought botanical potato seed to China for variety now worth billions in benefits

Junhong Qin, Research Assistant, CIP, surveys a local potato farmer.In the mid 1980’s, potato breeder and grower Peter VanderZaag, based in Ontario, Canada brought the botanical seed of the Cooperation-88 (C88) potato variety to Yunnan province in China. The C88 variety developed from that seed eventually became one of the most important potato varieties in Asia and it ended up being grown on 1 million acres (200,000 ha) of land annually. The estimated present value of benefits from planting C88 in Yunnan ranges from a low of US$ 2.84 billion to a high of US$ 3.73 billion. In a recent report published by the CGIAR, the impacts of this variety, developed by CIP in partnership with Chinese researchers, is assessed. It is said that tremendous benefits have been generated by the variety – and are still accruing. Starting in the mid-1980s, in response to the devastating effects of late blight, the International Potato Center (CIP) and Yunnan Normal University collaborated to develop the Cooperation-88 (C88) as a late blight resistant variety. C88 was officially released in 2001 and quickly became popular. Its success was attributed to its high yield, high quality, and good taste, in addition to late blight resistance. Read full report

Late blight scare: Migrant European pathogen generated aggressive new variants in India, not yet found elsewhere globally

Image result for potato late blight indiaAn international team of scientists from several countries including India, the UK and the US examined the population structure of the Phytophthora infestans pathogen that caused the 2013–14 late blight epidemic in eastern and northeastern India. Their findings were published online recently in the journal Nature.The data provide new baseline information for populations of Pinfestans in India. It was found that a migrant European 13_A2 genotype was responsible for the 2013–14 epidemic, replacing the existing populations. Mutations have generated substantial sub-clonal variation of which 19 were unique variants not yet reported elsewhere globally. The new A2 population is aggressive and has displaced the former populations. The pathogen is resistant to the fungicide metalaxyl, a commonly used fungicide Continue reading

EuroBlight report: New emerging blight clones continue rapid spread across Europe

Image result for potato late blightEuroBlight is continuously examining the ongoing evolution of the European population of the potato late blight pathogen and now reports on the 2017 results. Almost 1500 samples were genotyped from 16 countries last growing season. In its latest report, EuroBlight concludes that three new clones (EU_36_A2, EU_37_A2 and EU_41) continue to spread in 2017 and are displacing other populations. Around 75% of the samples belonged to defined clonal lineages also observed in previous seasons. Some clones are widespread and have been present in Europe for more than a decade, but the three emerging clones increased their combined frequency from 10% in 2016 to 28% of the population in 2017. The EuroBlight model of pathogen tracking is a rapid, cost-effective and co-ordinated approach to understanding pathogen evolution on a European scale. Data on the dominant clones has been passed to growers, advisors, breeders and agrochemical companies to provide practical management advice and shape longer-term strategies. More

Canadian potato growers get new seed treatment to help with control of pink rot and seed-borne late blight

Syngenta Canada Inc. announces the registration of Revus fungicide as a potato seed treatment for the suppression of pink rot and control of seed-borne late blight in potatoes. Pink rot is a soil-borne disease caused by the pathogen Phytophthora erythroseptica that thrives in wet, poorly drained soils. Infection typically takes place pre-harvest, as the pathogen enters tubers through the stem end and lenticels. “Every field has the potential for pink rot,” says Brady Code, eastern technical lead with Syngenta Canada. “It takes a very small number of infected tubers going over harvest equipment or getting by on the belt to put an entire season of work in jeopardy, and leave growers with far fewer healthy potatoes to ship.” Revus contains the active ingredient mandipropamid (Group 40), and works by protecting the daughter tubers from becoming infected with pink rot. More

Cornell potato virus Y Detection Training Workshops on again this year

Newer strains of potato virus Y spread by aphids cause damage to the flesh of the tubers. Photo courtesy Washington State UniversitySeveral newly evolved strains of the disease known as potato virus Y, or PVY, have emerged and are threatening the North American potato industry. These new strains can render potatoes unmarketable and reduce crop yield. What’s worse is the new viruses are particularly difficult to detect with the naked eye. Training workshops by Cornell College of Agriculture this year will cover field identification of PVY (strains O, N-Wi and NTN), including visual identification of foliar symptoms on 20 cultivars commonly grown in each region (NW, Mid-West and NE). Workshops will be hosted in Washington State, Wisconsin and Maine. A high attendance rate is expected because recent standardization of seed certification programs across the U.S. includes the requirement for documentation of inspector training. Continue reading

Drones show promise spotting PVY in potato fields

Image result for Drones potato fieldDonna Delparte, assistant professor in the Department of Geosciences at Idaho State University (ISU) in Pocatello, is working on using an unmanned aerial vehicle to spot PVY infected plants in potato fields and to record their specific locations for later control measures. In short, she says the technology works, but while it’s getting closer to being ready for the market, a few challenges still exist. Using a special camera, it is possible to fly a drone over a field and, within a reasonable level of certainty, determine precise locations of plants that are infected by PVY. Delparte’s team created a profile of what an infected plant looks like when seen through a special camera, called a hyperspectral camera, which scans dozens of slices of radiation, well beyond what a human eye can see. They then took that profile to the field, used it to identify infected plants and ground-truthed it using personnel on the ground, who verified which plants were infected. Using machine learning to tune the algorithm that evaluated the plants, the team reached an 89.8 percent success rate. More