Pesticide ban looming in the EU: Will diquat, thiram and pymetrozine be lost early 2019?

Image result for potato pesticide banAccording to a news item published by the National Farmers Union (NFU) in the UK, the pesticides diquat, thiram and pymetrozine look set to be lost as a vote on pesticides legislation in a Brussel’s Appeal Committee last week delivered a ‘no opinion’ position. Dr Chris Hartfield, NFU Senior Regulatory Affairs Adviser, said: “It is expected that within the next few weeks the EU will officially publish the regulations banning these actives. …these actives would be banned from use very early in 2019.” According to Dr Harfield, this decision will have significant implications for potato production in the UK. Diquat is much more effective than other available alternatives. Pymetrozine is an important insecticide which is used by most seed potato growers and in ware crops. With the ban on neonicotinoids, the loss of this insecticide will have a significant impact on resistance management in these crops. Read more

The mustard cure: Potato growers fight potato pests and boost yields with mustard crop

Related imagePotato growers in the Canadian province of Prince Edward Island (PEI) say they’ve planted more mustard than ever in 2018. They’re finding the bright yellow crop does more than fight wireworms — it also gives them a nice bump in potato yields in fields where mustard was planted first. “We have a bit of a problem with wireworm out in this area, as do a lot of areas, and this seems to be giving us some help with that,” said potato grower Hans Wilting. “It’s also giving some good results on some other diseases too, soil-borne diseases. And as a rotational crop, it’s adding a lot to the soil.” The Prince Edward Island Potato Board estimates wireworm costs the potato industry about $10 million a year in measures to control it and damage to crops. “It’s a good thing. It’s not a chemical, it’s something natural that you can put in the soil and it gives you a bump in yield and controls pests that you otherwise have to fight against with chemicals.” Read more

Syngenta develops RNA-based biocontrols for crop improvement

Image result for colorado potato beetleSyngenta is developing a new line of biocontrols based on RNA. The biocontrol can be designed to be very selective so that it only affects the target pest(s). So when it is sprayed onto the plant the biocontrol targets a crop pest such as the Colorado Potato Beetle, which can destroy entire crops; our initial data indicate that beneficial insects and even closely related species are not harmed. The RNA-based biocontrol is then broken down in the environment and does not affect the plant. Syngenta is committed to being transparent in how they are developed and to periodically make its data available. Syngenta is the first agrochemical company to share RNA-based biocontrols research as open data in order to engage in a new type of dialogue with scientists and researchers. Syngenta partners with the Open Data Institute to publish their data to the best practice standards in the industry. This data can be used by anyone for research and analysis. Watch how the biocontrol works on Colorado potato beetle. Read more

Ways to reduce the impact of black scurf on potatoes

Image result for black scurf potatoesRhizoctonia solani causes a number of common disease symptoms found in potato
crops including black scurf, leading to skin disfiguration, stunted plants and restricted
stem and plant growth. Syngenta Technical Services Lead Dave Antrobus in Australia examines the best management practices potato growers can undertake to minimise the damage caused by this disease. Writing in the latest issue of Potatoes Australia, he says Rhizoctonia solani causes a number of common disease symptoms found in potato crops including black scurf, leading to skin disfiguration, stunted plants and restricted stem and plant growth. There are specific conditions that help AG3 to survive and thrive. Its impact on potato crops depends largely on soil conditions at, and soon after, planting. Cool, wet soils typical of this time of year can often result in significant economic damage. The thing to remember with this disease is that complete
control is not possible, however the severity of the pathogen can be limited to a relatively small impact with best practice management. Read article on p36 of the June/July issue of Potatoes Australia

Researchers tease out the reason for late blight pathogen’s ability to evade immunity in potatoes

Image result for late blight potatoIn a paper recently published in BMC Evolutionary Biology, an international team of scientists describes how evasion of host immunity by a clonal variant of the potato blight pathogen Phytophthora infestans is associated with variation in gene expression without any apparent underlying genetic changes. According to senior authors of the study, Vivianne G.A.A. Vleeshouwers, Hannele Lindqvist-Kreuze and Sophien Kamoun, They studied two different races of the Irish potato famine pathogen, and we discovered that the difference invirulence between these races could not be ascribed to a genetic difference but rather to a difference in the expression of the underlying virulence gene. “This adds to our knowledge of how this important scourge on world agriculture evolves to evade plant immunity,” the researchers say.  Continue reading

Spray focus: Application methods the hot topics at SPot West field day

Image result for chemical sprayer potatoesThe first field walk of SPot West’s 2018 programme organized by AHDB Potatoes in the UK focussed on chemical control of PCN and Rhizoctonia as growers and agronomists met at Heal Farms, Shropshire to hear the latest developments on local research. Dr Matthew Back of Harper Adams University presented his research, which has shown that PCN attack helps attract the Rhizoctonia fungus towards the tuber stolons. A second demonstration compared different methods and depths of incorporating Nemathorin. The strip with incorporation to about 15cm on the bed tiller looked relatively good, but this could have been due to local variation, and treatment differences will become more apparent as the season continues. PCN initial egg counts range from 25-63, quite enough to stress Lady Rosetta in the current heat wave. Scott Cockburn of Syngenta led on a practical spraying demonstration. RVW Pugh kindly provided a Fendt sprayer, which compared four different types of nozzle at 2bar pressure. Read more

Australian experts underscore importance of certified potato seed for black leg disease control

Related imageAround the world, blackleg of potato is caused by several species of bacteria that can be carried and transmitted through seed tubers. Potatoes Australia spoke to Agriculture Victoria Research Scientist Dr Rachel Mann and ViCSPA General Manager Dr Nigel Crump about the identification and management of the blackleg disease. The main causal agent of blackleg in Australia is Pectobacterium atrosepticum although another bacterium known as Dickeya dianthicola was discovered in Western Australia in 2017. Dr Rachel Mann has been assisting with the traceback of the disease. “Blackleg is something that people can readily identify in the field, although it is not possible to determine which bacteria is causing it,” Dr Mann said. Seed tubers are the most important source of inoculum in the blackleg disease cycle. Therefore, management of the disease largely relies on the use of certified seed. “Due to the use of clean seed, blackleg is not very prevalent in Australia,” said Dr Nigel Crumm. Read full article on p20 of the June/July issue of Potatoes Australia

Making good better: British scientists boost popular potato variety’s blight resistance

Related imageProfessor Jonathan Jones from The Sainsbury Laboratory in Norwich, England is investigating ways that Maris Piper potatoes can be genetically modified to develop late blight resistance. According to Professor Jones, genetic modification has real potential to offer growers agronomic benefits, particularly in terms of developing late blight resistance. Against a background of aggressive potato late blight strains, combined with increasing losses of chemical plant protection tools, crops carrying genes that confer increased disease resistance would help to take the pressure off growers. Professor Jones is leading a team which has developed a new, improved Maris Piper potato with a stack of three genes that confer resistance to late blight. These lines successfully underwent field trials in the United Kingdom in 2017 and are on track to help fight the new blight strain 37_A2, which has established itself in Northern Europe over the last few years. Read the full article by Heather Briggs on p15 in the latest issue of Potatoes Australia.

Popular potato variety in Uganda getting a GMO makeover

Related imageVictoria is a popular local potato variety in Uganda. Farmers love it because it is high yielding. However, Victoria is also extremely susceptible to potato late blight disease. With each growing season, these farmers face a threat of 60 to 100 percent yield losses due to Late Blight. Climate related risks have worsened the situation leading to increasingly food insecure households. However, all is not lost. Researchers from the National Agricultural Research Organization (NARO) in Uganda, working closely with the International Potato Center (CIP), are about to complete multi-location field trials and laboratory analyses of an improved transgenic Victoria potato. These trials are part of a comprehensive risk assessment of the improved potato, to get it approved by Uganda’s National Biosafety Committee. Field trials of the improved Victoria variety have shown complete resistance to late blight disease without use of fungicides. Read more

Potato early dying disease: A major yield-limiting factor in Canada

Potato early dying (PED) is also known as early die and early maturity wilt. This disease is endemic in many fields with a long history of potato production, writes Dr Khalil Al-Mughrabi, potato specialist with Agriculture and Agri-Food Canada in New Brunswick province. There is increased pressure on Canadian processing potato production to increase productivity to remain competitive in regional and global markets. PED is a major yield-limiting factor in all major potato production areas of Canada, Al-Mughrabi writes. PED results in premature vine senescence and can limit potato tuber yield by as much as 50 per cent. The disease is primarily caused by the fungal pathogen Verticillium dahliae, but co-infection of potato by both V. dahliae and the root lesion nematode, Pratylenchus penetrans, can greatly increase the severity of the disease. Read more

US: Consumer trends put spotlight on blemish diseases

It’s not a surprise that the market for colored potato varieties, (red and yellows as well as fingerlings) has been on the rise in the last several years. What may be less obvious are the effects those market trends have on managing diseases. In the Red River Valley that means being more vigilant for blemish diseases like silver scurf. “We’ve got a great red market here in the valley and people are buying these table potatoes by eyesight. You know, they’re buying them by the way they look,” said Gary Secor, plant pathologist with North Dakota State University. He said as more specialty varieties come in from Europe and South America, including fingerlings, the look of those potatoes is even more important with consumers. As consumers become pickier, Secor said, that translates to pickier buyers and the producers have to become more selective as well. Read more

Trade spat: Mexican judge bars US potato imports into Mexico

Related imageMexico Daily News reported minutes ago that a federal judge has barred the import of fresh potatoes from the United States today on national security and bio-security grounds. The decision, made by José Francisco Pérez Mier of the Seventh District Court in Los Mochis, Sinaloa — a potato-producing state, overturned a 2016 decision adopted by the Secretariat of Agriculture (Sagarpa) to allow potato imports from Mexico’s northern neighbor. The judge said that Sagarpa’s reform to the Federal Law on Plant Health was unconstitutional because it didn’t include measures to protect against the introduction of plant diseases and therefore posed a threat to national sovereignty and security and crops such as chiles, tomatoes, eggplants and tobacco. The domestic potato industry could disappear if fresh potato imports from the United States continue, Pérez said. The amparo or injunction he handed down said the lack of protective measures “implies an imminent risk of plagues spreading on national soil.”  Continue reading

CPB alert: Jersey under threat of invasion by Colorado potato beetle pest, govt warns

Weather conditions for the next four days could enable an invasive insect with the potential to wipe out Jersey’s potato industry to reach the Island’s shores, the Environment Department has warned. The Colorado potato beetle is not established in the Island or the UK but it is prevalent in Normandy, which at its closest point is just 14 miles from Jersey. If it ever got a foothold here it would devastate the Jersey Royal potato crop, which is worth about £30 million per year. Just one fertilised female Colorado beetle can establish a breeding colony with the potential to destroy a field of potatoes by eating the stems and leaves. It is also partial to other crops including tomatoes, salad produce and parsley, which are all grown in the Island. Scott Meadows, head of plant health at Environment, said the current local weather conditions, combined with strong easterly winds and high levels of beetle flight over the nearby Normandy coast are putting the Island under threat. Read more

How fungicide data is helping to combat new potato blight strain

© Tim ScrivenerFungicide use data in the UK reveal that potato growers have already adapted their strategies to manage a new resistant strain of blight, although more needs to be done to combat the threat of tuber blight and further resistance developing in 2018. A strain of the most costly disease of potatoes, Dark Green EU37_A2, has spread to the UK since being discovered in the Netherlands in 2013. Of particular concern is its reduced sensitivity to fluazinam, an active that has been a blight control lynchpin since the early 1990s. This prompted warnings by resistance experts last season to change fungicide strategies. Data from crop recording software GateKeeper indicates that the industry took the warnings seriously (below), with back-to-back and late season use falling and applications of co-formulated fluazinam products increasing. Across the Channel in Belgium, blight expert Stef Dierickx says plotting growers’ blight applications against rainfall data showed that each spray in his comprehensive blight programme was applied immediately after a rain event. Read more

Mancozeb ruling: Good news for Canadian potato growers

On June 21, the Pest Management Regulatory Agency (PMRA) announced that the fungicide mancozeb will no longer be allowed in horticultural crops except for foliar use in potatoes.  A maximum of 10 applications per year will be allowed on potatoes with seven-day application intervals. That’s a relief for potato growers protecting their crops from late blight, but little solace for many growers of tomatoes right through to tender fruit.  “This is a perplexing ruling,” says Craig Hunter, crop protection advisor, Ontario Fruit and Vegetable Growers’ Association.  “If the product is safe for potatoes and poses no risks to human health or the environment as the PMRA says, then it should be a level playing field for all horticultural crops.” The issue, as Hunter sees it, is that both the United States and the European Union have re-evaluated and approved the use of mancozeb. “The logic for banning most uses of mancozeb in Canada is not clear or supported by scientific evidence,” says Hunter. “It is especially puzzling when more than 400,000 acres of potatoes can get up to 10 applications (>4 million acres) and all the onion seed needed for Canada cannot be treated with less than 10 kg total!” Read more