Potato Conference highlights agronomy innovation
More than 250 potato growers, agronomists and industry advisors braved sub-zero temperatures to attend the first ADAS Syngenta Potato Conference, held in Peterborough last week (30 November). Buoyed by positive news on prices and prospects, the event provided some crucial technical agronomy innovation and marketing pointers for the direction of the industry over the coming years. Key note speaker highlights are captioned, followed by their presentation reports:
In a worst case scenario legislative changes could halve growers’ profitability, warned James Clarke.
John Purslow reported trials to counter the interaction between FLN and soil-borne diseases can enhance yields and quality.
SAC trials with fludioxonil have repeatedly shown exciting potential as a ’on-stop’ seed treatment, reports Stuart Wale.
Legislative changes coming
James Clarke of ADAS warned that potato growers could see a 15% reduction in profitability as a result of legislative changes in the pesticide approval process, however that could be compounded by a 35% hit if a ’worst case scenario’ to meet water quality standards - such as the Water Framework Directive (WFD) - is enacted. "In many instances the meeting water quality standards could have a far more profound impact than the Approvals proposals. We need to find a way to mitigate the dangers and minimise the risk," he said.
Potato growers are the third highest users of pesticides per hectare, after strawberries and onions, according to Mr Clarke. Unsurprisingly fungicides are by far the largest component, but, with the relatively small growing area, in terms of total use the crop is way down the list, he added.
Mr Clarke highlighted that, for the most part, the current thinking of legislators looking at a balance between voluntary initiatives and regulatory imposition, was putting far greater emphasis on the voluntary efforts. He also noted that from his perspective the current direction was to aim for a balance between producing food and protecting health and the environment though voluntary approaches supported by regulation only where essential.
He believes professional potato growers who are already part of a well organised assurance scheme and operating to retailer or processor protocols have little to fear by way of impending legislative changes for pesticide application and record keeping. "But with Integrated Pest Management (IPM) becoming an increasingly integral part of any agronomy regime, one of the challenges will be to demonstrate what has been done and how?"
Mr Clarke cited advances in application technology, the more effective use of prediction models and the advances in plant breeding as routes to redress potential impacts of legislative changes. "Strong stewardship of products will be an essential element," he added. "Increasingly we are seeing the way products are advocated for use changing with stewardship programmes, primarily for better application, improved resistance management and protecting the environment.
"It is vital that everybody participates and complies with these stewardship initiatives. Generally potato or vegetable growers have very actively engaged with these, but it will be even more important in the future," he said.
New product innovation
Syngenta Technical Manager, Jon Ogborn, reported very high take up of the company’s recent stewardship initiatives, including a cessation of in-furrow application of the nematicide, Nemathorin, and a best use recommendation for overall application and incorporation. "We have introduced significant advances in potato crop application in recent years, to optimise product performance," he added.
Mr Ogborn reported that a new Syngenta Potato Nozzle is now manufactured using a super-hard polymer, which is better able to resist the effects of abrasive spray products, such as mancozeb. "Operators can achieve far better coverage of leaf and stems for improved blight control and Reglone desiccation with the Potato Nozzle, compared with conventional nozzles. Furthermore, the new Syngenta Potato Nozzle has the added benefit of an improved spray pattern and, with a narrower spray angle, is less drifty and so offers additional spraying opportunities."
To further improve future blight control Mr Ogborn highlighted new developments around Europe’s top performing fungicide, Revus. These include a potential new solution aimed to give added curative activity, along with another single-product option that would target both late blight and Alternaria early blight control.
"Alternaria is an increasing challenge, possibly a result of changing varieties, weather patterns and fertiliser uses," he warned. Trials in the UK have demonstrated that Olympus has proven effective. However, for the best results the experience indicates that it should be applied before symptoms are seen – which in the last two seasons has been before the end of June, especially on susceptible varieties.
To improve blight fungicide application timing, Mr Ogborn advocated growers utilise the free Syngenta Blight Cast system. This web-based service provides a unique prediction of blight risk periods, weather forecast and spray windows, which creates a powerful tool to help with more effective blight fungicide selection and timing.
Exciting new seed treatment
Fludioxonil seed treatment could offer potato growers a single product solution to cover the vast majority of wound diseases, skin infections and field origin diseases, according to Dr Stuart Wale of SAC.
"It does appear to be a step forward in seed treatments," he enthused. "The fact that we have seen activity on Black Dot and a reduction in Common Scab makes it unique and extremely exciting." Dr Wale described his first trials, which saw a 50% reduction in tubers with Common Scab, as a "jaw-dropping experience".
SAC researchers have subsequently trialled the seed treatment on a wide number of varieties and conditions, with the greatest effects seen on varieties most susceptible to Common Scab. "It’s doing a good job where we need it most. The results suggest it will have a useful role, especially on unirrigated crops, or where water supplies are difficult," he advised.
"Results on Black Dot had encouragingly seen a reduction in both the incidence and the severity of skin disease from seed-borne infection, but fludioxonil offers a wider spectrum of disease control than current products, including Rhizoctonia Black Scurf." Dr Wale also reported trials results where the seed treatment was having a high level of control of Skin Spot on harvested tubers, although the disease is unlikely to be mentioned on the label.
But Dr Wale stressed the importance of the physical treatment process in achieving good coverage and product retention on the seed. SAC trials had shown that frequently less than 25% of current seed treatment was actually staying on the seed tuber. He stressed the need to calibrate applicators for every change in seed stock being treated and to replace nozzles regularly. "It’s necessary to ensure there is a constant flow of seed tubers across the roller table, and to take account of tuber shape and size. Operators should be looking to achieve 75 to 90% coverage," he said.
Whilst new seed treatment application technology is being developed, he believes the SAC work has demonstrated good treatment can be attained with existing conventional roller table applicators, providing operators pay close enough attention and get everything absolutely right.
Enhancing crisp yield and quality
Norfolk agronomist and potato specialist, John Purslow, presented the initial results of a third year’s trials looking at Nemathorin and Amistar applications to protect yield and quality of crisping potatoes. The 2010 season has confirmed the significant improvements in both yield and tuber quality seen in previous years, which he attributes primarily to control of free living nematodes (FLN) in the soil.
"The direct feeding activity of free living nematodes can have a dramatic effect on the root mass and the potential of crops to produce and support the green top that is essential to drive yield. This is especially marked in typically less vigorous varieties that can be severely checked by FLN damage to the roots."
He adds that frequently the leaf canopy of crops attacked by FLN appears to crash early, which stops tubers maturing evenly and compounds the yield loss and quality issues.
"Furthermore, we are undoubtedly seeing some interaction with soil disease pathogens – most likely Rhizoctonia – that appears to be more active and have a greater impact where roots have been damaged by the FLN. This is in turn affecting tuber quality and consistency, which can have a marked effect on fry colour," he added.
Mr Purslow considers the effects on fry colour may stem from the diversion of plant sugars to the roots and tubers to repair damage caused by nematodes and disease. This could in turn be raising the sugar levels in tubers, which will caramelise on frying and have an adverse darkening effect on the resulting crisps.
"There is a complex mechanism occurring which we need to seek to identify and understand. But what is abundantly clear is the improvements in both overall yield and the processing quality of the tubers that can be achieved with combinations of Nemathorin and Amistar applications," he advised.
