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A growing role for biologicals?

As the agrochemical crop protection armoury available to growers diminishes, interest is increasing in the potential role of so-called ’biologicals’. Heather Briggs finds out more.

Biological products for control of botrytis in strawberries are available in the UK.
Biological products for control of botrytis in strawberries are available in the UK.

Crop protection is becoming increasingly difficult as most conventional growers know too well. There are fewer approved chemical protection products available and the discovery of new molecules has become a mere trickle since the 1980s. To add to their problems, resistance to chemical active ingredients is developing, from certain types of aphids all the way through to black-grass.


Perhaps not surprisingly then, interest in ’biological’ crop protection materials is increasing. But there are a number of challenges for biological protection products entering the highly competitive chemical market, warns Bill Clark, commercial technical director for the National Institute of Agricultural Botany (NIAB).


“While there is certainly some resistance management potential, there is a certain lack of awareness of advances in the biologicals sector,” says Mr Clark. In addition, the sector often suffers from a perceived lack of efficacy and as a crop cannot be allowed to fail, most of the customers are risk-averse.


“The truth is, at the moment the perception of many growers is biologicals are not yet good enough to compete with conventional pesticides, particularly at broadacre crop level,” he says.


Tim Lacey, biologicals product manager for Bayer CropScience, acknowledges this perception in the industry, adding while there is still good chemistry available it is harder for broadacre farmers to justify the extra costs of using biologicals.


Nevertheless, there is growing interest in the sector, largely driven by the loss of conventional pesticides through EU legislation, resistance development and diminishing pipelines. Agrochemical companies such as Bayer CropScience and BASF are buying specialist product companies; Bayer has bought AgraQuest and Prophyta, while BASF has acquired Becker Underwood, giving both business’ access to portfolios in the biological markets.


At present, biological products are aimed more towards high value vegetable and fruit crops, which have the extra challenge of the absence of blemishes, often meaning they require additional protection to that needed on combinable crops.


Mr Clark says: “The more forward-looking view would be we will eventually come to rely more on biopesticides, not as replacements for conventional pesticides but as partners with conventional pesticides.”


Both chemical and biological plant protection products need to go through a similar registration process, says Mr Lacey. However, some data requirements are fewer for biologicals – for example those relating to residues – which can mean authorisation is slightly easier. 


Dr Gwynn adds the rigour, standards and timeline for assessment of a dossier, are the same for a biopesticides as for a conventional pesticide. 


However, despite registration costs being lower for biologicals, Mr Lacey insists it is important to keep in mind the bigger picture; whether products are conventional or biological, it takes years to develop a new product. 

Current issues with biocontrol agents

  • Issues with registration – what is a pesticide?
  • Often very specific – single disease
  • Level of control rarely comparable with conventional chemistry
  • Often tested ‘wrongly’ (versus conventional)
  • Need to be used in integrated programme

“The typical cost of bringing a new product to market, including screening new actives, setting up all the tests and collecting the support data works out at between £200 million and £300m,” he says. “When you then consider the direct cost of registration for synthetic chemicals in the UK is about £150,000 compared with £30,000 for a biological, as a proportion of the total cost it is not so important.” 


Another challenge is obtaining intellectual ownership of a biological product; for example, garlic extract occurs naturally, so protecting the rights which would come from developing a biological pesticide is not so simple.  


The biological nature of the product has another challenge too; the stability of the product in storage. “You have to remember it is a living product,” says Mr Lacey. “This means the shelf life may not be the same as a synthetic chemical. As a result, it may become more necessary to buy protection when the need occurs rather than long in advance, which can lead to some challenges.


Roma Gwynn, of Biorationale, who has worked in crop protection in agriculture and horticulture for more than 25 years, says: “We are still at a relatively early stage of development, and we need economic support to develop biological controls so we can evaluate the opportunities there are.”


Mr Lacey observes European countries such as France are showing their support of the biological sector with financial incentives for grower adoption and additional legislation, although this is not happening at UK level. 

Types of biocontrol available

  • Natural plant host defence elicitors   
  • Synthetic plant host defence elicitors
  • Biocontrol/antagonists

The specialists believe there are certain areas which could become more involved in biological crop protection.


Rob Storer, speciality crops product manager for BASF, sees areas such as seed treatment as being a really important market for the biologicals of the future. 


“At the moment we have a seed treatment for soya bean crops, which is not directly relevant to the UK,” he says. He foresees some of the speciality crops being protected with biologicals in the near future, mostly driven by supermarkets demanding blemish-free products with no residues at all. “However, speciality growers tend to be more open to dynamic new products, and are often closer to their end markets where the issues around pesticide are.” 


Biologicals are already working well under glass, but moving them on to broadacre crops will happen on a greater scale when technology moves forwards, says Mr Storer.


“At the moment some can be more temperamental in terms of weather conditions – they work under some particular conditions but not others – and that is the subject of ongoing work.” 


Mr Lacey observes biologicals started to be used on high-value, high-risk crops and are just starting to work through to broadacre field vegetables, and then on to potatoes, oilseed rape and other combinable crops.


“Acceptance is slowly trickling through the different levels of production.” 


Some countries are already moving ahead, with trials underway on soft rots in potatoes and some cereal diseases.  


“Products are mainly bioinsecticides and biofungicides as there are few bioherbicides,” says Dr Gwynn. “These products are based on semiochemical [pheromones], micro-organisms and botanicals. 


According to the BCPC Manual of Biocontrol Agents, there are a number of products available for broadacre crops across the globe; the same product may be used on several crops.  


Bayer CropScience has two biological products already on the market in the UK; Contans WG controls sclerotinia in a wide range of vegetable crops and also oilseed rape, Serenade ASO is effective on botrytis in strawberries and has an EAMU for soil-borne diseases including cavity spot in carrots. 


“Serenade has positive signs for club root control in canola [OSR] in Canada, but it hasn’t attracted much interest for that particular use in the UK as yet,” says Mr Lacey.


He adds the Bayer biologicals pipeline is looking good too, with a biological nematicide for free-living nematodes, as well as insecticides for sucking pests being available in the near future.


As resistance becomes more of a threat, integrated pest management (IPM), which became compulsory in January last year, is also increasingly being regarded as the smart way forward, alongside biological control agents such as macro-organisms, micro-organisms, botanicals and semio-chemicals. 


Biological crop protection products available globally

  • Wheat: More than 20 products
  • Barley: More than 20 products
  • Oats. About 15 products
  • Potato: More than 50 products

Mr Storer says: “IPM can be used as a decision support system.


"It involves linking crop husbandry, nutrition and irrigation with varietal selection, with the use of biological and conventional pesticides.” 


Healthy soils are considered to be key to healthy plants that are then more able to withstand the constant attacks from crop pathogens. 

Mr Storer adds: “Delivery and precision application of pesticides will go hand-in-hand with IPM; products will be applied in the precise dose necessary at the optimum time for control.” 


Mr Clark says: “Growers cannot afford to wait until there is disease in the crop, they have to act prophylactically. What they really need is a good early warning system so all spraying is timed for optimum effect. 


“Biologicals will be an effective complement to, but not a replacement for, chemical plant protection.” 

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