A note from the Project Director: The following is a thought-provoking article on the future of microbial and other biologically-based pesticides. This is a slightly modified preprint of a Guest Editorial due to appear in Phytoparasitica (The Israel Journal of Plant Protection Sciences) Vol. 25(3), 1997. We thank the author and the editor of Phytoparasitica for permission to use this article.
The jury is in: the existing strategy for commercializing biological pesticides has stumbled, badly. Fueled by lavish venture capital money and unrestrained enthusiasm for biotechnology, a flush of biopesticide companies arose in the 1980s to exploit the extraordinary potential biologicals offered as environmentally benign alternatives to chemicals. The widely predicted environmental driven surge in demand for biological pesticides never materialized. Some producers of biopesticides, such as Biosys (nematodes, viruses), Entotech (bacteria), and Crop Genetics International (viruses, bacteria) have disappeared. Mycogen (fungi initially, bacteria subsequently) has survived essentially by reinventing itself as a seed company. EcoScience (fungi) and Ecogen (bacteria, fungi, nematodes) have undergone repeated downsizing. Even powerful American Cyanamid has abandoned insecticidal viruses despite years of research and development effort.
Biopesticides capture a scant 1.4% or $380 million of the $28 billion dollar global market for pesticides. Natural enemies and antagonists (microbials, predators, parasitoids) comprise a mere $164 million of the $8 billion dollar insecticide market; if Bacillus thuringiensis endotoxins are regarded as chemicals, and there are persuasive arguments to this effect, then the contribution from biologicals shrinks to $72 million dollars. Biologicals have been unable to penetrate beyond niche markets, and even this role is threatened as a new generation of pesticide chemistries have come on-line and transgenic plants reduce the size of the sprayable pesticide market. In short, biologicals are not realizing to any significant extent their fundamental mission of reducing chemical pesticide usage.
Consider insecticidal nematodes. Researchers have touted nematodes for control of soil-inhabiting insect pests for decades, stressing their extraordinary pathogenicity to insects, broad range of activity as a group, ease of mass culture, and exemption from government registration in most countries. Yet nematodes have failed to measurably reduce the groundwater contamination, wildlife kills, and toxic residue problems associated with over reliance on soil insecticides. Despite their prominence within the world of biologicals, nematodes are applied to considerably less than 100,000 hectares every year, and these tend to be hectares for which conventional insecticides are unavailable. Is it any wonder that many now question whether biologicals can be taken seriously in agriculture?
The current approach to commercializing biopesticides is based on a chemical pesticide model. This paradigm emphasizes major crops and is based on cheap, stable products that are easy to scale-up and use. Biological agents fit the chemical model poorly. Using the insecticidal nematode example again, production costs of $50-75 per hectare far exceed those of most chemicals, restricting use to high-value specialty crops. Nematode shelf-life at 3 to 6 months falls well short of the conventional standard of two years, necessitating special handling and distribution, and contributing to inconsistent performance. Strains which have proven efficacious when produced and applied by researchers, often perform poorly when tested on a larger scale. Efficacy of nematode-based insecticides is more impacted than chemicals by ecological interactions of suboptimal temperature, soil type, thatch depth, and irrigation. Nematodes are inactivated if stored at temperature extremes and are incompatible with some agricultural chemicals. Despite industry advances in production, formulation, and application technology, all aimed but not quite succeeding at endowing biologicals with the same characteristics as chemicals, biologicals lag appreciably in traits prized by growers: price, performance, and ease of use.
A change in approach is needed for the next century, one based on the realities of biological systems. Three facets should be considered: industry, growers/extension, and researchers.
A new biologically-based approach for the biopesticide industry might emulate business sectors that have successfully overcome biological limitations. For example, the food industry has demonstrated that low stability products are not a fatal flaw. Similarly, the microbrewery industry has demonstrated that there is a strong market for "fresh" product sold without preservatives. The keys have been local small batch custom production and quick turnover leading to high quality products. This concept might be adapted to biopesticides.
Much of the expense in producing microbial pesticides concerns formulation, storage, transport, waste disposal, and capital. Local production, perhaps in disposable fermenters, wouldeliminate each of those steps, providing improved cost. Local production would mean that only "fresh" biologicals would be applied, providing improved performance. One outlet for this technology could be the existing cottage industry of small biological control companies that currently produce and sell insect predators and parasitoids. But grower coops, golf courses, even gardeners might grow their own microbial pesticides since the "do-it-yourself" technology could potentially be minimally more challenging than fermenting beer or wine in the basement. It may even be useful to examine the explosion of personal microbreweries in the U.S. where $150 buys a supervised fermentation session and 52 liters of brew. This could provide sufficient insecticidal nematodes to treat 10 acres at $15 per acre.
Growers similarly need to consider an alternative paradigm. Contact chemical agents have conditioned growers to evaluate control based on quick knock down. Biologicals work more slowly, requiring different, more complicated criteria such as yield for measuring effectiveness. It is also worth considering whether anything less than perfect produce is permissible. This sort of mindset change is essential for encouraging broader use of biopesticides.
This transition will require growers better educated about biological control technologies. But first, the educators must be educated. A study requested by three U.S. congressional committees and conducted by the Office of Technology Assessment evaluated the obstacles to grower acceptance of biological agents. This comprehensive report noted that Cooperative Extension has been extraordinarily successful in providing farmers with information on using chemicals, but has not been historically strong in delivery of information on biologicals. The study concludes that many extension personnel, especially at the county level, are neither broadly or deeply trained in pest management, and training in biologicals is limited at best. Extension has developed an immense knowledge base to support the use of chemical pesticides, but no comparable database exists for any biological agent. Extension personnel must be provided with new knowledge for transmittal to growers if attitudes and behaviors are to change.
Alternatives to the chemical pesticide paradigm are poorly developed. Researchers too have tended to be absorbed with the chemical pesticide model and largely left production issues to industry and evaluation issues to extension. They now have an opportunity to provide leadership in building a new research base that develops detailed, reliable protocols for small batch custom production, and for examining longer-term crop benefits rather than only how many pests were killed over a narrow time span. Moreover, researchers have tended to emphasize microbials as inundative biological control agents to the virtual exclusion of alternative approaches. In part, this is because our history of reliance on chemical pesticides has hindered the development of the strong ecological traditions among insect and plant pathologists that are characteristic of their predator and parasitoid counterparts. Here, again, longer term approaches, conservation and inoculative biological control, are worthy of increased focus. Notwithstanding minimal effort with microbials, successful examples of these approaches are not limited to predators and parasitoids, and both approaches are poised for renewed emphasis as more selective chemical pesticides and transgenic plants become widely available.
Biopesticides are at a crossroads. The early vision of biologicals becoming significant pest management tools for major row crops has faded in this decade. No foreseeable new technology, including genetic engineering, is likely to change this reality. In the next decade, biologicals will either begin to play a meaningful role in specialty crops or become a curiosity relegated to organic farming. Industry, growers, extension, and researchers must come together and think "outside the mold" to realize the former.
- Randy Gaugler, Rutgers University, New Brunswick, NJ
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