European Union
May 3, 2010
Despite a history stretching back more than a century, biological control methods are a long way short of being a mainstream feature of modern agriculture. To better understand the role biological controls can play in crop protection, alongside the factors that influence their success or failure, and the economics of a sector that faces challenges rather different to those of the chemical industry, one ENDURE research team has just completed a major 234-page report.
The report, Review of factors influencing the success or failure of biocontrol and recommended orientation for new R&D projects , includes not only a review of recent scientific research on biocontrols, but a survey of farmers and biocontrol retailers, and a detailed look at the costs involved in producing a biocontrol agent, in this case a microbial.
The report has been produced by ENDURE’s RA4.3 team, which brings together an international group of researchers from countries including France, Italy, Spain, The Netherlands and the United Kingdom in addition to representatives of the International Biocontrol Manufacturers Association, and tackles both classical and conservation biological control.
Different types of biocontrol
For ENDURE’s researchers, classical biological control (ClBC) is “the intentional introduction of an exotic, usually co-evolved, biological control for permanent establishment and long-term pest control”.
Currently, the most commercially important type of biocontrol is augmentation or augmentative biological control. In contrast to ClBC, this involves measures such as increasing natural enemy populations, applying natural substances or the use of semio-chemicals. Augmentative biological control can, for example, be achieved through mass culture, periodic release and colonisation for the suppression of native or non-native pests (for more details see Orr, D., 2009, Biological Control and Integrated Pest Management in Integrated Pest Management: Innovation-Development).
To best describe conservation biological control (CBC), ENDURE’s researchers borrow the description of Landis et al (2000): “The manipulation of the environment to enhance the survival, fecundity, longevity, and behaviour of natural enemies to increase their effectiveness.” CBC is, say ENDURE researchers, an “increasingly promising field of research”.
The report begins by examining the current status of CBC research relevant to the major cropping systems in Europe and, while the authors acknowledge there has been a focus on CBC for the management of invertebrate pests (the field for which the terminology was originally coined), they note that the principles of CBC could be applied equally to the management of plant pathogens and weeds (see CBC for pathogens below).
Examining the protection and/or enhancement of natural enemies or other naturally occurring organisms which reduce the effect of pests, ENDURE’s researchers note that this can be achieved by manipulating their environment and providing resources to increase their effectiveness.
They report that the strongest effect for CBC on natural enemies was associated with technical aspects such as landscape management and the provision of refugia and resources within it. In 99% of 154 reports of these CBC techniques, “there was judged to be accompanying benefit to natural enemies and the evidence for this was strong in 46% of the reports.”
The research team concentrated its efforts in analysing those reports concerning the crops studied by ENDURE’s case study teams (such as apples and pears, grapevine, arable crops such as wheat and maize and field vegetables including carrot and onion) and they report the largest proportion of reports showing strong evidence that CBC promoted natural enemies were from field vegetables and vines, and to a lesser extent arable crops, orchards and maize.
In fact, reports relating to vines also showed the largest proportion of reports showing strong evidence that CBC promoted pest control, mostly through the provision of refugia or resources.
Given the above, it is perhaps no surprise that the knowledge gaps in CBC techniques identified by the reports frequently cited landscape management as a priority for future research, followed by the provision of refugia and resources. A number of other challenges to the implementation of CBC were also discussed in the literature under review, encompassing areas such as the lack of interdisciplinary research, high research and development costs and the problems of ensuring successful knowledge transfer.
CBC for pathogens
ENDURE’s research team has also examined the possible role of CBC in tackling air-borne pathogens. CBC, they say, “represents a virtually untapped resource for the management of air-borne diseases and much work will be necessary to explore this promising area.”
They suggest future research could include manipulating the resident phylloplane microflora (the bacteria and other micro-organisms on the leaf surface of plants) to foster the establishment of components with the highest effects against air-borne pathogens and breeding plant varieties able to harbour a larger fraction of the natural phylloplane microflora that are antagonistic or compete with selected major air-borne plant pathogens.
In terms of tackling soil-borne pathogens, ENDURE’s researchers note that this has been under discussion for more than 40 years and a range of cultural practices, such as crop rotation, tillage, residue management, solarisation and biofumigation or biodisinfection and compost amendments, are part of the armoury. “These management practices that contribute to control soil-borne plant pathogens are not exclusive from other biological control methods,” they conclude. “On the contrary they should be used in association with other biological methods such as the use of specific biological control agents. However, it is our opinion that these conservation biological control methods have been neglected…the sustainable approach requires that all the available methods should be used in association in order to drastically reduce the use of chemical pesticides.”
| In pictures: Protection of a tomato plant with a microbial biocontrol agent |
| In plant A the inoculation of the leaf pruning wound with Botrytis cinerea has led to the invasion of the petiole stub (ps) by the pathogen and resulted in the development of a stem canker (sc). In plant B the treatment of the wound with a biocontrol agent immediately after inoculation with B. cinerea has drastically reduced the development of the pathogen in the petiole stub and fully protected the stem. |
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| The inside story: what is happening in detail |
| A wound - here the surface of a leaf-pruning wound on a tomato plant seen in scanning electron microscopy - provides numerous ports of entry for the spores of the pathogen. |
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| Spores of Botrytis cinerea (red arrows), alone in an unprotected wound (photo A) or together with bacterial cells (green arrows) in wounds protected with a biocontrol agent (photo B). |
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| Several days after inoculation, the pathogen has completely invaded the unprotected wound and a dense mat of mycelial filaments is visible on its surface. |
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| In the protected wound the development of the pathogen was drastically reduced and the bacterial biocontrol agent multiplied heavily, both on the plant tissue and on the pathogen. |
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Tackling weed problems
The development of CBC strategies for weeds is in its infancy, note ENDURE researchers, who identify the management of crop residues by conservation tillage and by manipulation of crop rotations and the management of habitats (refugia and resources) for invertebrates as techniques offering the most potential. They caution that “considerable research effort is needed if strategies are to be developed and tested and if risks and benefits are to be explored to the satisfaction of both researchers and growers.”
“Quantification of the effectiveness, reliability and cost of CBC strategies for weeds under realistic field conditions is particularly important if it is to be adopted into farm practice,” they add.
Research on specific crops
Examining the status of research on specific crops, ENDURE researchers identified a steadily increasing number of studies being produced, with the largest number of reported successes concerning air-borne diseases and pathogens achieved through the use of microbials (things such as bacteria, fungi, protozoa and viruses). However, they also note that there is a growing body of literature on plant and microbial extracts and other substances.
They identify several types of knowledge gaps including the near absence of information on the biocontrol of major economically important crops such as winter arable crops, the lack of reports on biocontrol of diseases of major economic importance, such as rusts and powdery and downy mildews, and a limited body of knowledge on the specific mechanisms of action.
In terms of beneficials for classical (the introduction of non-native biocontrol agents) or augmentative (boosting natural enemy populations) biocontrol against insect pests, researchers had lots of material to examine. In fact for classical biocontrol (ClBC) there is a bank of knowledge stretching back more than 100 years.
Looking at the more recent evidence (1991-2006) researchers have identified releases involving 55 different biocontrol agents (almost all of them hymenopteran - insects such as wasps) aimed at 35 pests, more than half of them Hemiptera (bugs). These were generally conducted in orchards, in particular citrus orchards.
The ENDURE researchers make several recommendations, including that policymakers avoid over-regulating ClBC and that scientists create a shared international database to make it both easier to estimate the success of ClBC and to improve traceability.
Options available across Europe
One group of ENDURE researchers has also compiled a survey of biological active substances approved in the EU and on biological control products (BC products) authorised in several countries, with a particular emphasis on the seven crops or cropping groups being investigated by ENDURE’s case study teams.
Post harvest treatment of apples with a bio-fungicide. Above right is a bio-fungicide-treated apple inoculated with the pathogen Botrytis cinerea . Above left is a control (untreated) apple inoculated with B. cinerea . The disease control obtained by using the bio-fungicide is clear. © Michelina Ruocco, CNR, Italy.
Substances suitable for biological control and registered on the EU Pesticides Database include botanicals (plant substances derived from simple processing or extraction, including repellents and growth regulators), semiochemicals (pheromones, kairomones and allomones that modify the behaviour of pests or their natural enemies), and micro-organisms such as bacteria, fungi, protozoa, viruses and viroids.
The team also analyses another category, which it describes as other plant protection substances of natural origin, this includes diverse substances and products such as limestone powder, kaolin and diatomaceous earth.
The team has also identified registered plant protection substances for uses in the seven crops or cropping groups in France, Germany, Switzerland, Spain and the UK.
They conclude that none of the EU Member States has the variety of biological control agents (BCA) found in Switzerland, which has the largest number of microbials, botanicals and pheromone blends; this they attribute to the flexible regulatory approach adopted by Swiss authorities before they began to implement EU Directive 91/414/EEC and the related framework, and the sustained support offered by experts in the country’s agronomic institutes.
The position regarding the use of invertebrate BCAs varies in each country. In France, for example, invertebrate BCAs cannot be registered and the use of them does not even need to be formally declared. In contrast, they must be registered in Germany, where ENDURE’s partner the Julius Kühn Institute publishes a regularly updated official list.
New regulation to ease introduction of biocontrols?
As explored before on this website, the biocontrol sector can sometimes find itself in a difficult position in terms of European regulations as its products had previously been treated in the same way as chemical pesticides and therefore had to follow the same lengthy and costly registration procedure.
One group from the research team has been seeking to address these issues with representatives from the biocontrol industry, and held two workshops with regulatory experts to not only identify difficulties and problems but also to collect positive experiences and perspectives. ENDURE members have summarised these findings and presented them to representatives of the European Commission and the European Food Safety Authority.
Both the new regulation concerning the placing of plant protection products on the market and the Framework Directive make some provisions for biological control approaches but there remain some outstanding areas of concern. ENDURE’s researchers suggest that: “[Biological] Industry should fix priorities, prepare rationales and make substantiated proposals dealing with data requirements considered inappropriate, unnecessary or unrealistic,” as there is scope within the new product placement regulation “to adopt or amend technical and other guidance documents”.
Difficulties and conditions for success at field level
ENDURE’s researchers have highlighted a number of areas contributing to the difficulty of ensuring biocontrol works in the harsh conditions found in the field even though success may have been proven in the lab. On the quality of BCA formulations they identify a lack of investment in the development of effective formulations and delivery systems. “The relatively small effort invested in target-specific sprayers, compared with the investment in laboratory studies, has led to unbalanced development, and exemplifies the need for closer integration between formulation and engineering research,” they say. “The challenge is to get effective formulations so that biological control agents can be easily applied by farmers.”
Economic aspects: cost analysis
While there is a groundswell of support for more biological solutions as alternatives to chemical pesticides in both organic farming and IPM systems, say researchers, the development and commercial success of biologicals is made more difficult because of the size of the companies involved and the fact it is a young, relatively undeveloped market.
They identify four areas where these constraints are apparent - size of the market, cost of production, costs of registration and business profitability - and use the real case of a microbial biocontrol agent (MBCA) to illustrate these points.
Size of the target market
In most cases MBCAs are being developed for small, if not niche, markets. Worldwide MBCA sales were €620 million in 2008 (€122m in Europe) including products with insecticidal or fungicidal effects, compared to worldwide chemical insecticide and fungicide sales of €21,000m. MBCAs, with the exception of Bt (Bacillus thuringiensis ) products which can be used in larger crops such as grapes and cereals, are mainly used for speciality and covered crops, sectors which are growing, if at all, at only a slow rate. The organic market does look positive though, with some countries seeking to develop this sector (for example, France has set a target of turning 20% of its agricultural production area to organic methods by 2030).
In addition, the potential market for MBCAs is highly fragmented, taking in a long list of crops such as carrot and onion which are generally bundled together as ‘minor crops’ of little interest to the large chemical companies. Because of the specificity of their products, MBCA manufacturers have to invest in these crops knowing that economies of scale can never be reached.
Cost of production
ENDURE’s researchers say that contrary to the synthesis of chemicals, producing MBCAs requires a complicated and very expensive four-phase production process starting with fermentation and running through extraction, purification, and formulation and packaging. And throughout this process expensive measures to ensure there is no contamination have to be taken. As a consequence the MBCA in question is more than twice as expensive to produce compared to an equivalent chemical pesticide (see Table 1 below).
Table 1: Compared structure of the production costs for a microbial biocontrol agent (MBCA) and a chemical insecticide (source: IBMA)
| |
Typical insecticide |
MBCA |
Comments |
| Sales value |
100 |
100 |
|
| Type of production cost |
|
|
|
| Raw materials |
8* |
29 |
40% lost material for MBCA by solid fermentation process |
| Packaging |
1 |
2 |
|
| Energy and miscellaneous |
1 |
2 |
|
| Manpower |
5 |
9 |
|
| Consumables |
2 |
3 |
|
| Amortisation |
4 |
11 |
|
| TOTAL |
21 |
56 |
|
* Costs are expressed as a percentage of the sales value of the commercial product
Cost of registration
The estimated cost for registering a microbial biocontrol agent is currently lower than that for a chemical pesticide, though the size of the investment is still very high in comparison with the market potential. ENDURE’s researchers have carried out an evaluation which shows that bringing a MBCA to market is around four times less effective than its chemical equivalent (see Tables 2 and 3 below).
Table 2: Compared potential costs of registration for a microbial biocontrol agent (MBCA) and a chemical pesticide (source: IBMA)
| Area |
Study type |
Cost for chemical (€) |
Cost for MBCA (€) |
| Toxicity of the active substance |
Acute studies (6 tests) |
140,000 |
140,000 |
| Sub-acute (rat study) |
140,000 |
120,000 |
| Mutagenicity |
40,000 |
May be waived |
| Toxicity on cultured cells |
10,000 |
Not required |
| Toxicity of the formulation |
Acute studies |
140,000 |
140,000 |
| Toxicity on cultured cells |
10,000 |
Not required |
| Environmental fate |
Soil, water, air |
200,000 |
70,000 |
| Biology |
Mode of action etc |
150,000 |
50,000* |
| Ecotoxicology of active substance |
Birds, fish, bees, algae, daphnia, earthworms |
60,000 |
40,000 |
| Beneficials |
20,000 |
May be waived |
| Ecotoxicology of formulation |
Birds, fish, bees, algae, daphnia, earthworms |
60,000 |
40,000 |
| Beneficials |
20,000 |
- |
| Residues |
8 trials/crop |
80,000 |
May be waived |
| Development of analytical methods |
100,000 |
Variable** |
| Formulation |
Physical properties, shelf life etc |
200,000 |
220,000 |
| Efficacy |
8 field trials |
40,000 |
40,000 |
| TOTAL |
|
1,410,000 |
860,000 |
* Cost of strain identification
** For example, development of strain-specific markers
Table 3: Compared estimated market potential for a microbial biocontrol agent (MBCA) and for a chemical pesticide (source: IBMA)
| Year |
Estimated sales value (€m) |
| Chemical pesticide |
MBCA |
| 1 |
0.1 |
0.05 |
| 2 |
1.2 |
0.15 |
| 3 |
6.0 |
0.90 |
| 4 |
15.0 |
1.50 |
| 5 |
35.0 |
3.50 |
| Total early sales |
57.3 |
6.10 |
| Plateau sales |
120.0 |
15.00 |
| Registration costs |
1.410 |
0.860 |
| Ratio registration/early sales |
2.4% |
14.0% |
| Ratio registration/plateau sales |
1.1% |
5.7% |
Business profitability
Comparing estimated production and other costs relative to the sales value at plateau level highlights large differences between chemical pesticides and microbial biocontrol agents. In fact, say ENDURE researchers, the gap between the two in terms of estimated profit is nearly 10-fold in favour of a chemical pesticide (see Table 4 below).
Table 4: Compared margin structure estimates for the production and sales of a microbial biocontrol agent (MBCA) and a chemical pesticide (source: IBMA)
| %* |
Chemical pesticide |
MBCA |
| Sales value at plateau level |
100 |
100 |
| Cost of production |
13 |
56 |
| Gross margin |
87 |
44 |
| Cost of sales |
21 |
15 |
| Cost of research |
8 |
12 |
| Cost of administration |
4 |
3 |
| Earnings before investments, taxes and amortisation (EBITA) |
54 |
14 |
| Profit after taxes, provisions and amortisation |
18 |
2 |
* Costs and margins are expressed as a percentage of the sales value of the commercial product
Outlook for the biocontrol industry
ENDURE’s researchers say it is clear that the profitability of a biocontrol business is much less attractive than the chemical sector. This maybe explains the retreat of the large chemical companies from the biocontrol sector in the 1990s. They suggest that for the smaller biocontrol businesses there are two options: develop into larger markets such as grapevine and field crops, which will require venture capital backing, or enter into venture agreements with other manufacturers or suppliers to build up a wider product portfolio.
Socio-economic aspects: market analysis and outlook
Figures from the Organisation for Economic Co-operation and Development (OECD) show considerable investment has been made in public research on BCAs over the past 40 years (an estimated $5,000m) and in order to establish why they have not been more widely adopted ENDURE teamed up with public opinion specialist Agridata to conduct a pan-European survey of biocontrol retailers and farmers to establish the size of the biocontrol market in Europe and to identify key factors which could influence its future evolution.
The survey found that the biocontrol market in Europe was worth an estimated €204m in 2008, the majority used in protected crops, followed by grapevine and food production. Almost 40% of the market was made up of sales of beneficial insects, compared to 25% for micro-organisms and 21% for semiochemicals.
Researchers identified 12 factors deemed to have significant influence on the future development of biological control.
Nine factors were deemed to have a positive influence
- Ability of manufacturers to invest in research and development
- Financial strength of manufacturers
- Direct involvement of leading distributors
- Pull from the fresh food wholesalers and food industry
- Demand from consumers and non-governmental organisations (NGOs)
- Incentives given to growers
- Education of advisers and growers
- Availability of Decision Support Systems (DSS)
- Regulatory obstacles to chemical pesticides
Three factors were deemed to have a negative influence:
- Regulations not adapted to biological control
- Discovery of novel, effective and safe chemicals
- Development of new resistant crops
In a further step, researchers asked half of those surveyed (320 respondents), to weight each factor they considered important on a scale of one to 20, allowing the team to calculate an influence index (percentage of respondents who selected the factor as important), a weight index (average of the weights attributed to the factor by those respondents who selected it as important) and a growth index (combining the other two scores according to the formula: influence index x weight index divided by 10) (see Table 5 below).
Table 5: Impact of 12 factors on the future use of biocontrol agents by European farmers according to a survey of 320 farmers
| Factors |
Influence index (%) |
Weight index (scale from -20 to +20) |
Growth index |
Rank of positive influence |
| A: Registration for biological control products remains as present |
12 |
-15 |
-18.0 |
- |
| B: Involvement of distribution |
65 |
8 |
52.0 |
4 |
| C: Size/strength of the manufacturers |
55 |
12 |
66.0 |
3 |
| D: Incentives to growers |
87 |
18 |
156.6 |
1 |
| E: Education of advisers and growers |
27 |
8 |
21.6 |
5 |
| F: Decision Support Systems available |
12 |
7 |
7.2 |
9 |
| G: Pull from wholesalers and food industry |
43 |
16 |
66.8 |
2 |
| H: Stringent registration of chemicals |
16 |
14 |
22.4 |
6 |
| I: New safe chemical pesticides |
42 |
-12 |
-3.0 |
- |
| J: Progress in R&D of biocontrol |
8 |
14 |
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Species
