Consultant David Ann advises supermarket growers on production methods. His mission is to ensure supermarkets fresh produce technical production requirements are met without compliance being uneconomic for growers. He works for the Agriculture Development and Advisory Service (Adas).
“What the supermarket wants is assurance that production methods are ethical,” he says. “That is, food is produced utilising as few non-sustainable resources as possible, in a way that's safe to the environment. They also want high quality, blemish-free produce, preferably with no chemical residues.”
While accepting these are high expectations, he supports supermarkets' efforts to address what he describes as a worthy aim that challenges producers. But, he adds food production must be profitable for the grower. “Otherwise supermarkets will ultimately be short of produce and faced with empty shelves.
“It's my job to review production strategies and question growers to check all avenues to provide environmentally advantageous methods, including non-chemical means, have been explored.”
Ann highlights the practice of sterilising soil for controlling soil-borne diseases. He explains it is not about which product to recommend. “You need to ask whether sterilising is the best option for the situation, why production needs to be so intensive, and whether new land is available. If ñ as with many soil-borne diseases ñ pesticide intervention is the only viable solution, the question of which sterilant chemical to select is then addressed,” he says.
The impact of inputs also needs to be assessed for environmentally responsible production. Ann says that for soil sterilants used in soil-borne disease control, the choice is usually between methyl bromide, Basamid (dazomet) and the use of steam.
Soil sterilants, by their nature, also kill non-target organisms. “The array of micro-organisms, insects and other soil flora and fauna is vast,” he explains. “Most are not harmful pests, weeds or diseases. Some beneficial fungi and other creatures will attack and devour potentially harmful plant pathogens and insect pests. So the impact of the sterilant on all soil life must therefore be considered,” he says.
“The use of methyl bromide is being drastically cut because it's considered harmful to the earth's atmosphere. As a result, it's likely it won't be available to any grower beyond 2005. In some circumstances it may result in a residue problem, and already some supermarket retailers do not permit its use or do so in very specific circumstances.”
Basamid works by producing a gas ñ methylisothiocyanate ñ on contact with warm, moist soils that is toxic to soil-dwelling organisms. It is lighter than air, moving laterally and upwards through the soil profile, and is trapped by polythene covers. It then breaks down to disperse harmlessly in the soil and air.
Practicality and cost often rule out the steaming option, and its use is not without environmental impact because the power to generate steam has to come from an energy source. Ann explains that in many situations, Basamid may be the option that delivers effective and economic disease control with least environmental impact.
The environmental impact of all agricultural production methods, not just horticultural ones, is becoming more important. Ann highlights the recent common agricultural policy mid-term review. “The EU wants to see subsidies for farming moving away from production-driven to being more environmentally acceptable management of the land,” he says.
If growers are to remain successful, they must focus on the developing needs of their key supermarket customers ñ and in turn consumers ñ and devise better economic ways of addressing them.
JUSTIFYING INPUTS SAVES COSTS
Fruit producer James Dearing of Clockhouse Farm, Kent, thinks justifying inputs saves time and money. Following increasing pressures from supermarkets on growers to account for cropping inputs and production methods, he switched in his choice of soil sterilant and is also a step ahead of legislation changes.
Intensive production on 75 acres of strawberries grown under polytunnels is unavoidable he says, because of limited additional land and short rotations. This allows pathogens to thrive in the soil.
September marks the start of the soil sterilising opportunity to eliminate disease and prepare land for plantings in the following spring. Dearing describes verticillium wilt as the most feared key soil borne disease, and with no in-crop fungicides, sterilising the soil is the only option. He says: “Let wilt get away and the result is a patchy field, difficult picking conditions and lower yields. We simply can't afford a crop that is unproductive.
“All land is routinely tested for verticilium wilt. It's important to justify soil sterilisation; not only to meet supermarket concerns, but also from the point of view of avoiding treating a non-existent problem. The £150 per five acres cost gives us confidence that we're targeting treatment correctly. It is also far cheaper and less time consuming than treating a crop unnecessarily.”
The variety's disease resistance rating is then considered before deciding whether or not the land is to be treated. Most producers grow a range of varieties, the more susceptible ones, such as Elsanta, have a lower treatment threshold level compared to more resistant varieties such as Symphony. Disease rating is a factor in variety decisions, but with much down to supermarket preference, there is little scope for choice.
Traditionally, Clockhouse Farm used methyl bromide to sterilise the land, but due to failing control, recent reduction in dose rates prompted Dearing to reassess treatment options. With methyl bromide being withdrawn by 2005, Dearing decided it was time to seek a new solution.
Dearing applied Basamid (dazomet) for the first time two years ago. He says: “It delivers improved disease control compared to methyl bromide and has no crop residue issues, so while methyl bromide is still accepted for use by the end market, I'd prefer to opt for something with a good environmental profile.”
He adds that Basamid can be applied by farm operators, thus offering control, convenience and environmental benefit. Dearing explains that methyl bromide requires a contractor. “It's important to take advantage of a weather window. The soil needs to be sufficiently moist ñ with a water holding capacity of around 60 per cent ñ and to be above 10?C in order to achieve best results.” It is also important, he adds, when the conditions are right, to get on with the job and not have to rely on a third party.
“Basamid delivers effective control, and has the added bonus of controlling weeds, saving significant hand weeding costs,” he says. “All in all, it's very cost effective.”
SNAITH OPTS FOR ALTERNATIVE
Snaith Salads ceased the use of methyl bromide on all 26-member enterprises from the end of June 2003. General manager Graham Ward explains the decision followed another winter of problems in the salads industry with pesticide residues. Most of them derived from in-organic bromide residues.
The Yorkshire-based marketing co-operative represents 25 per cent of total production of round and curly lettuce in the UK. Despite the introduction of a new code of practice from the Pesticides Safety Directorate (PSD), Ward believes the key problems with residues relate to rainfall and water table variation. “Residue problems will continue to arise depending on the weather. For that reason and because alternative techniques are available, Snaith Salads has taken the decision to cease using methyl bromide as a soil sterilant. The board of the group believes that growers should manage using alternatives, and avoid risking embarrassed customers resulting from monitoring residue results.” Ward adds that many other lettuce growers are taking similar decisions.
Ian Gillot, technical manager for the British Leafy Salads Association, agrees. He asks why the use of methyl bromide should continue at all. “Why continue using it when its unpredictability causes bad publicity for the industry every single year?” argues Gillot.
He highlights Basamid as a good alternative: “The application techniques for using this material have improved considerably. It is certainly better than having to defend excessive crop residues year after year,” he says.
NEW TREATMENT FOR RHIZOCTONIA LAUNCHED AT BP2003
A new potato seed treatment ëRhiNo' was launched to growers and agronomists at British Potato 2003 this week.
Its introduction is timely given that 70 to 85 per cent of seed potatoes are reportedly infected with rhizoctonia, potentially costing growers between £50million and £75m a year.
Providing both preventative and curative protection from seed infection, the liquid treatment is based on new active ingredient flutolanil. In addition, owing to the systemic nature of this unique compound, there is also some control of the spread of disease from soil-borne rhizoctonia infection to the progeny.
Developed in UK trials over five years, RhiNo, applied six weeks prior to planting, delivered 14 per cent better control compared to an existing liquid seed treatment, where more than five per cent of tubers were infected. Further trials revealed RhiNo maintained 100 per cent control of stem canker and 75 per cent control of black scurf, a figure 17 per cent above the competitor product. In terms of overall yield, trials show RhiNo has produced 15 per cent higher yields compared to the untreated control and three per per cent more than pencycuron.
Certis general manager Peter Hingley says the superior control could be down to RhiNo's activity against all the different strains of rhizoctonia (or anastomosis groups) found in the UK. “Potatoes are generally most vulnerable to the AG3 strain of the disease, but five other strains can infect potatoes and cause stem canker and stolon pruning. RhiNo gives added protection, where other treatments do not,” he says.
Hingley adds that flutolanil has been used in other countries as a potato-seed treatment for six years and has become the market leader in both the Netherlands and in France for the control of this devastating disease. “Furthermore, its good environmental profile, high crop safety, and low toxicity means RhiNo is safe to use and environmentally acceptable,” he says.
Speaking at the launch, Dr Stuart Wale, head of crop services at the Scottish Agricultural College (SAC), says with the summer's warm and dry weather, and potentially drought- stressed crops, rhizoctonia is likely to be more frequent on seed crops and is therefore a greater risk to next season's crops unless controlled. He says: “Unlike some diseases, it can be effectively controlled. A good seed treatment will effectively eliminate seed-borne rhizoctonia.”
Wale explains that Rhizoctonia solani is a fungus that causes both black scurf and stem canker, which have an impact on both quality and yield. “It causes black lesions, cracks and russeting on the tuber surface,” he says. “The same fungus also causes stem canker that disables growth. It attacks stems and stolons making them less vigorous, resulting in irregular tuber formation and less top growth. It's readily recognisable.”
He adds that the increaseing importance of quality and produce presentation of potatoes on supermarket shelves means rhizoctonia is now a very important disease, especially for the pre-pack sector. “Quality is more important than yield. Black scurf can cause a crop to go into the bag trade rather than pre-pack. That's a loss of perhaps £70 a tonne,” he says. He notes that size and shape implications of the disease affect the processing sector as well as pre-pack.
Unveiling new SAC research at the launch, Wale explains that where the fungus survives in soil, the study reveals it transfers directly to infect seed tubers. “It's well known that rhizoctonia from the soil will attack sprouts, but this new research shows that rhizoctonia is more stimulated and attracted to seed tubers,” Wale says.
He says the research shows there is justification to treat seed if soil-borne rhizoctonia is present, whether or not there is an existing seed infection. He adds that it is nonetheless important to always wash and examine seed and utilise rotations of at least six years between potato crops.
Discussing the introduction of RhiNo, Wale explains a key factor is that the new seed treatment will control all the different rhizoctonia strains, where alternatives do not. He says with a lower dose of active ingredient required than other rhizoctonia treatments, it has a good environmental profile, and being a liquid, RhiNo also offers enhanced user-friendliness.
EUREPGAP CONFERENCE
The EurepGAP conference will prepare members for the revised fresh produce protocol, achieved through a two-year examination by the technical and standards committee.
EurepGAP chairman Nigel Garbutt says: “Members often have to contend with entirely different conditions affecting production, but the current and revised protocol will allow them all to continue to achieve and maintain EurepGAP certification.
“It's the first link in the chain which stretches through to the consumer, ensuring there is confidence in the food they buy. Those that have joined realise that as well as being a vital safeguard, [membership] enhances their commercial potential.”
Garbutt, who stressed that EurepGAP wishes to have the closest possible relationship with other trade organisations, will announce a strategy to enhance the transparency of its work.
Kristian Moeller of EurepGAP says: “We are doing everything to ensure our objective of creating improved traceability and good agricultural practice is recognised.”
Research shows that product traceability is a concern for all respondents to a survey of executives in the food industry. Fifty-seven per cent believe that food safety will increase in importance if there are more international food scares. Governments are responding with more legislation and the EU directive that comes into effect in 2005.
Almost half of the respondents to the EurepGAPsurvey feel that poor collaboration in the supply chain is a barrier to food safety. The perception is that the greatest risks are back up the supply chain. Ninety per cent of respondents view farmers as high risk, while 86 per cent rank manufacturers as the highest risk.
“One of the challenges for the industry is to achieve greater levels of customer confidence in food safety,” says Ray Treseder from the consumer business practice at accountants Deloitte & Touche. “This has to be achieved in an environment characterised by complex product flow, and a deflationary economy that squeezes retailers' and manufacturers' budgets.”
The majority of respondents agree there is conflict between pressures in the marketplace and the need to address supply chain integrity and food safety issues.
David Edwards of CMi, the leading food safety and assurance company, adds: “Leading retailers are well aware that, in the minds of the consumer, they carry the first line of responsibility for food safety and integrity ñ especially for fresh produce and own- label products. However, the root causes of problems are often out of their direct control and arise at earlier points in the supply chain.”
Retailers, manufacturers and suppliers who take a broader view of the supply chain will see significant benefits. Positive action and investment in new processes and technologies are needed, says Deloitte & Touche in its report. Early adopters will find new opportunities using food safety to their advantage to meet both customer and regulatory demands.
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