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Oranges hold back sprouting in store

Topping the list of priorities for potato storage research is evaluation of residue-free treatments aimed at reducing growers’ reliance on CIPC. DAVID MOSSMAN has been finding out about a novel active ingredient which comes from a surprising source.

There is a growing list of alternative sprout suppressants based on plant essential oils, some of which have been granted regulatory approval in recent years and are enjoying a degree of success while others seem to have fallen by the wayside. Carvone (recovered from caraway seeds) is sold in the Netherlands under the brand name Talent while mint oil is marketed here as BioX-M from Juno Plant Protection. Clove oil, which has also been tested in the UK, faces an uncertain future but Arysta LifeScience has been working on a competitor which could be granted registration as early as next year.

This latest ‘natural’ product to undergo trials at AHDB’s Sutton Bridge Crop Storage Research in Lincolnshire is extracted mechanically from orange peel. The active ingredient, limonene, is reckoned to hold back dormancy break by burning off developing sprouts.

Arysta’s Don Pendergrast sees real potential for the use of orange oil as a stand-alone treatment though he suspects that potato growers and store managers will be particularly interested in using it in sequence with growth regulator maleic hydrazide (MH) and the widely-used sprout suppressant chlorpropham (CIPC), both of which are part of his company’s existing product portfolio.*

Dutch trials carried out at PPO Lelystad showed promising results on a range of varieties when orange oil was compared with established treatments such as DMN (1,4-dimethylnapthalene), Biox-M and GroStop (CIPC). ‘They have been working on orange oil at PPO for five years and the product is due for registration any time now in the Netherlands,’ Mr Pendergrast explained. ‘We’re a little bit further back here in the UK but we’re hoping to get approval in the early part of 2019.’

Abstraction reform offers a chance to innovate

Much is changing in the world of potato production, from agronomy to the regulatory and business environment and the introduction of new technology. Bayer has commissioned a series of articles focusing on these forces for change. This instalment looks at water use and the introduction of digital licencing.

Abstraction reform has been on the political agenda since Defra published a White Paper on the topic in 2011. The current licencing system was introduced in the 1960s and is widely accepted to be in need of reform. ‘It is literally an analogue system in a digital age,’ explains Paul Hammett, NFU national water resources specialist.

‘It doesn’t consider the pressure that population growth or climate change will exert on the system and it lacks the flexibility needed to allow users to take water in times of plenty or to fully utilise the technological innovations growers are adopting to improve water use efficiency.’

After several public consultations on the issue, Defra announced in 2017 that it would seek to reform abstraction practices through voluntary measures and an extension to the catchment-based approach. This put policy development in the hands of those at the local level – namely the Environment Agency (EA), the Rivers Trust, catchment groups, and abstractors – and means bespoke solutions can be developed for each catchment based on its unique circumstances.

‘This bottom-up approach has been largely welcomed by licensees, especially the acknowledgement from Defra that for it to be successful will require flexibility and innovation in licensing,’ says Mr Hammett.

Fundamental to the success of the new system will be the abolition of paper-based licences in 2019 and the introduction of a modern system of digital licensing. By moving it online the Environment Agency intends to streamline the application process and expand the type of services available, such as applying to trade water or amend an existing licence as well as making it easier to report volumes abstracted.

‘This is something growers are particularly keen on,’ Mr Hammett suggests. ‘There is enthusiasm for a system that enables those who need water to access it either through local trading of permits or shared storage. Part of the solution rests in being able to store more water out-of-season, but to enable this users need help.

‘Reservoirs require capital investment and while grants are available to reduce the cost through measures such as the countryside productivity scheme, they cannot be included in capital allowances. Reforming this area of tax law would be more worthwhile in the long term as it allows investment to reflect changes in enterprise activities.’

Contract topper addresses diquat quandary

A Lincolnshire contractor is offering neighbours a new service to ease workloads during busy times when crops need to be flailed off quickly and efficiently. The combination of unusually dry weather this season and uncertainty over the future of diquat meant that the timing of the launch could hardly have been better.

For many years G. & D. Matthews Ltd were substantial potato growers in their own right but more recently they have been happy to work with a number of local farmers who have suitable land in their rotations but who don’t want to plant potatoes themselves. Over the last few seasons they have also collaborated closely with others further up the supply chain so that risks can be shared more fairly.

David Matthews’ first foray into farm contracting was way back in the 1980s when he and his father ran a potato harvesting business, operating from Leaveslake Drove, West Pinchbeck near Spalding. In 2002, James (the third generation of the Matthews family) joined as technical director. This summer we caught up with them both on nearby Holbeach Marsh to find out about their latest venture.

A crop of second early variety Marfona grown by A. H. Worth & Co Ltd at Manor Farm, Holbeach Hurn, was being defoliated prior to harvest. James was driving the tractor, a shiny new John Deere 6250R equipped with row-crop wheels and a six-row (three-bed) flail system. A two-row front-mounted Baselier haulm topper (Standen) had been teamed up with a pair of trailed units on a folding frame (Scotts Precision Manufacturing Ltd, Fishtoft, Boston), complete with a full set of six ridge press wheels to help reduce tuber greening.

David Matthews is banking on a move towards mechanical haulm destruction, given the uncertainty surrounding the use of the market-leading chemical desiccant. ‘I looked into the future of diquat but I didn’t get a definitive answer as to whether it was going to be available this season or not,’ he explained. ‘The latest information would suggest that it will be banned in the next few months. The other angle this year has been that with such dry weather it has been too dry in a lot of cases to use diquat, unless you had plenty of irrigation.

‘We started flailing last year when we bought the Scotts Trinity system. We already had the Baselier topper and we’re looking to do 1500 acres plus this season,’ he added. ‘The three units are independent of each other which means they follow the contours of the land and the ridge wheels on the back can be very useful in a year like this when cracking and greening is a potential problem. If conditions are wet and ridge consolidation is a problem we have the option of taking those wheels off but nine times out of ten they are a big plus.’

Late blight: an integrated approach

The development of fluazinam-resistant blight strains has placed further pressure on spray programmes. It has been estimated that growers spend £20m each year on fungicides in an attempt to keep blight at bay.

Dr Sue Cowgill, senior scientist at AHDB says late blight is very much in the spotlight at the moment because both the pathogen and the availability of control measures have changed. The push to adopt integrated pest management (IPM) is across the board, she adds, with growers keen to adopt new approaches.

IPM is by no means a novel concept but it focuses on adopting a range of cultural and chemical methods to target development of pests and diseases at different times of the year to create a more robust control programme and a sustainable approach.

‘Overall, changes in chemical regulations makes us feel that there are fewer new actives coming to the market, and some of those that are available are being lost,’ Dr Cowgill observes. ‘Using IPM can take the pressure off the remaining actives by minimising the negative effects of resistant pests and diseases.

‘In the case of late blight, the use of resistant varieties strengthens all other control options if, for example, the weather is bad and sprays cannot be applied. Practical implementation of IPM can be a real challenge though,’ she warns. ‘Growers are aware of the options but they need to be able to combine these to meet their other needs.’

Although the lifecycle of blight is well understood, varietal resistance in some of the most widely grown crops is relatively low and there is less flexibility and margin for error. This means the numbers of precautionary fungicide applications are high and this has seen the development of fluazinam resistant strains emerging. Despite growers being offered a glimmer of hope this season with the newly available Zorvec Enicade (oxathiapiprolin), which offers longer spray intervals and lower use rates with no known cross-resistance, experts are urging growers to adopt new forecasting methods, including guidance formulated by pathologists at the James Hutton Institute, Dundee. The Hutton Criteria offer new treatment thresholds which are said to give growers increased confidence in risk-based spray applications while reducing unnecessary use of fungicides.

Dr Alison Lees, plant pathologist at JHI explains: ‘Better disease forecasting is very important. Our new model has been very successful in testing a new sustainable fungicide programme. We are very aware of the high risks for growers associated with blight epidemics but so far during field trials no blight has been found, chemical usage was reduced, and input costs were lower.’

For the full article see our July/August edition


Western technology meets the developing world’s needs

The World Potato Congress in Cusco, Peru, was a sell-out, according to the organisers. Given the fact that the International Potato Center (CIP) was heavily involved, the emphasis was on food security in the world’s poorer nations.

Douglas Harley, managing director of Gygnet Potato Breeders at Milnathort near Perth, is a long-serving member of the WPC organising committee. ‘The conference was impressive and very well attended,’ he told Potato Review, ‘and for me it was a chance to see the home of the potato.

‘With CIP as the principal organiser there was quite a strong scientific theme, as you’d expect. There was a lot of focus on Latin America and on using potatoes as a means of feeding the starving rather than concentrating on frozen French fries, for example. When WPC gets to Dublin in three years time the emphasis might be more commercial. We have the intention of moving the event around the world from developed to less developed nations to achieve that balance and allow people see both sides of the coin.’


Participatory varietal selection of biofortified potatoes in Ambato in Huancavelica, Peru. Two communities Tacsana and Castillapata are growing and helping to select new biofortifed varieties of potatoes. The potatoes are higher in zinc and iron and are being developed to help counteract pervasive anemia. CIP is partnering with the grupo Yanapay to select possible varieties for release.

‘World Potato Congress Inc. was conceived as a global networking organisation which uses its conference to achieve that aim but there is a lot more going on behind the scenes as well,’ Mr Harley explained. ‘We’re trying to bring together western technology with a Third World developing industry. It’s a not for profit organisation and it’s all about promoting the benefits of potatoes to the wider society. And as a seed merchant, a global conference allows me to look at different opportunities in terms of new variety development.

‘There is currently quite a lot of work on genetics and manipulation of DNA, some of which is quite beyond me but which seems to be moving at speed in various different parts of the world. True seed certainly has a place in the Third World but I’m not sure how competitive it will be on yield and processing quality which are the main drivers for development. It is difficult to see how an inbred line will give consistency of factory output.

‘You have to remember that true seed has a four-week delay in canopy cover compared to conventional seed with it’s large reserve of starch which it uses to grow rapidly. There is a saving on seed production and distribution but there is also a yield penalty though in parts of Africa, for instance, where there is a long growing season, that disadvantage might be less significant.’

AHDB’s Claire Hodge came back from her Peruvian trip full of enthusiasm. ‘It was an amazing experience and the location was quite special,’ she said. ‘There was a lot of time devoted to the humanitarian side of potato production and to subsistence farming, but what I found interesting was that there was also a lot about sourcing robust seed, whatever system you are working with.

‘Among the scientific elements there was discussion on genetic developments and technology without anyone actually using the words “genetically modified”. There are huge steps forward on that and on moving from tetraploid to diploid production. It looks like we’re getting closer to reducing the yield penalties but if we’re talking about nutritional benefits and reducing the impact [of potato production] on the environment, then it seems there is now a shift and that reduced yields might become more acceptable.’

For the full article see our July/August edition


Big savings from a small outlay

Relatively limited expenditure can greatly improve the efficiency and running costs of potato box stores, the results of a major industry trial have confirmed.


The two-year project has identified a number of ways in which owners of both existing and new stores can improve their performance by either retro-fitting a range of features to improve the even-ness of airflow throughout the store, or installing them as original equipment. The trial was ‘industry led’ with 70% of the £800,000 funding coming from Innovate UK.

The project was run in a specially built 1/3 scale model store at Sutton Bridge Crop Storage Research (SBCSR) and in commercial facilities, including units operated by Branston Ltd. The work represented possibly the most detailed monitoring of airflow ever completed in a potato store, says Mr Cunnington says Adrian Cunnington, AHDB’s head of crop storage research.

‘We took measurements at every slot in the face of the box store at both ends, so on a stack that was 10 boxes wide and eight boxes high that was a total of 160 airflow monitors,’ he recounts.

‘In standard form we found that nearly 75% of the air produced by the fans to dry and cool the crop wasn’t going through the boxes but was disappearing everywhere else.

‘There was massive inefficiency in such systems so we started to examine how we could improve things by installing plenum walls and testing the use of side and top sheets. These measures improved airflow dramatically – by as much as factor of three.

Prior to this latest project, AHDB and FEC Energy had carried out a trial that indicated huge differences in the efficiency with which energy was being used in potato stores.

‘That started to ring alarm bells because we were finding running costs of £4/tonne in the best stores but £12/tonne in the worst,’ Mr Cunnington recalls. ‘We began to examine the causes of those differences and there are a number of things which came into play.’

The project highlighted one key difference between bulk and box stores, explains Ray Andrews, managing director of lead partner Crop Systems Ltd. ‘Bulk stores with under-floor ducts work well because the air literally has nowhere else to go but through the crop. In box stores the air comes out of ducts above the crop and we have much less control over where it goes. We found some instances where boxes at the far end of the store saw virtually no air movement at all.’

For the full article see our July/August edition

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