Until and unless the general public insists on purchasing organic produce, large scale marketing of natural products will likely be most successful if they are cost competitive with the chemicals they are attempting to replace.
Formulations for some of the natural products marketed in California have been less than desirable with respect to odor, consistency, and ease of application compared to conventional products.
Many growers mix products for several uses together to save on application costs and distributors may offer price breaks on such mixtures. Natural products will be more acceptable if they can be mixed with conventional products.
It is common practice for a grower to buy larger quantities of a product than are needed for a single application if there is a cost break for buying in bulk. Product remaining at the end of a season will be carried over and used the next year. This requires a product to have a reasonable shelf life.
Fumigant nematicides typically provide a rapid kill with little or no residual activity while organophosphates and carbamates may not kill immediately or at all but provide continuous nemastatic activity for several weeks after application. In some cases, soil microorganisms may find natural products inviting food sources which will lessen their effectiveness in the soil.
Commercialization will likely be more acceptable if a natural product can be produced without needing to be reared in or on another organism.
Quality control is an important component of all commercial ventures. Living organisms and resulting products could be more difficult to produce uniformly than traditional chemicals. Potency must often be determined via a bioassay procedure utilizing living organisms rather than via a standardized chemical test. Media on which living organisms are reared is often not specific to a particular organism and extreme care must be taken to assure contamination of product does not occur.
Traditional chemicals are typically marketed by experienced agricultural companies which produce and sell a variety of agricultural products. In contrast, in many cases natural products which have been sold in California have been developed by relatively small concerns which may have a viable product but little experience in marketing through agricultural channels. Traditional chemical companies may also offer incentives to growers to buy a combination of products (e.g. a nematicide, a herbicide, an insecticide) which can't be easily matched by companies producing a single product.
The cost of registering a product which includes a variety of tests required to prove the safety and efficacy of a product is a significant concern. This is an area in which a natural product because it is perceived as safe may have an advantage because fewer safety tests may be required. Even so, costs to register a new product can still be substantial and prohibitive to some small companies. Prohibitive costs associated with obtaining a registration have been cited by some companies marketing natural products in California as reasons they don't seek a registration in spite of having nematicidal potential.