Changing Models for Commercialization and Implementation of Biocontrol in the Developing and the Developed World

Microbially based biocontrol of plant diseases differs fundamentally from chemical control, but pesticide regulations for microbial and chemical pesticides remain similar. In the United States, the Food, Insecticide, Fungicide and Rodenticide Act (FIFRA) (19), like similar laws in other countries, requires any material making a pesticidal claim to be registered. The Act was in response to widespread concern regarding the safety and environmental effects of pesticides. Registration requires significant effort, time, and expense to conduct toxicological, environmental, and in some cases, efficacy testing. However, the nature and advantages of chemicals and microbials are quite different, especially between chemical fungicides and endophytic symbiotic microbes that act through changes in plant gene expression. Further, some organisms with pest control activities were never covered by FIFRA, including obligate symbionts such as rhizobia and mycorrhizal fungi and larger organisms such as nematodes and predatory insects. Furthermore, FIFRA and similar regulations are designed primarily for specific, individual agents, and not for complex mixtures such as composts, manures, and teas made from these largely unregulated sources, even though they have activity against plant pests and their active ingredients may be similar to those in registered pesticides. In addition, pesticide regulations cover only materials that make specific pesticidal claims, i.e., they do not cover agents that make claims for general improvement of plant health and plant quality. Finally, there is great potential for use of microbial agents in the developing world, although full-scale production, marketing, and registration are simply too expensive for these societies. To overcome this economic difficulty, some countries have substituted locally produced products for imported ones (2,55). There are numerous microbial products listed for the control of various pathogens, insects, or weeds. Copping (14) lists 17 species or strains of fungi or bacteria that have been commercialized for insect control, 37 for control of pathogens or nematodes, and 14 mycoherbicides. This must be an underestimate; Faria and Wraight (20) list 171 commercial mycoinsecticides and mycoacaricides over 12 species or subspecies of fungi. Even this is an underestimate because these authors did not include many nonregistered products or those produced by governmental agencies. In fact, many products or preparations with activity against plant pathogens or other pests are not registered pesticides. Instead, they may be marketed as plant inoculants or plant strengthening agents, which gives these products a marketplace advantage because the time and money necessary for registration are avoided. Moreover, because many microbial agents can be propagated easily, local distribution systems have been developed. As a consequence, biocontrol production, distribution, and methods of use have evolved in diverse ways, each of which has advantages and disadvantages. There are strong incentives to develop biological products that fall outside the registered pesticide model, and it is likely that more products with pesticidal activity will be sold outside this framework. Much of this paper will deal with biocontrol based on Trichoderma strains, but other systems will be discussed as well. Finally, there are safety implications for the different systems that have evolved, but modern taxonomic studies provide insight into this aspect and also will be discussed. It is important to consider the perceived benefits that microbial agents have in different parts of the world. In the United States and other developed countries, the agents are considered to be useful but not essential. However, in the developing world, as perceived by the Association of Asian Pacific Agricultural Research Institutions (AAPARI), biopesticides and biofertilizers are considered extremely important. Applicators in the developing world may not wear protective clothing (communication in AAPARI meeting cited in Acknowledgments), so there may be serious health hazards to the use of toxic chemical agents. In addition, fertilizers are rapidly becoming too expensive for use by smallholders in many parts of the world, and biofertilizers in their various forms are considered to be essential components of food security in many countries.