Genetic modification techniques have not exactly been able to win over consumers. The task of turning isolated genes into working crops out in the field has been more costly and time-consuming than anyone imagined.

'There was a lot of promise talked about within the industry, where the timelines were underestimated,'said Dave Schmidt, CEO of the industry-backed International Food Information Council (IFIC).

Farmers, looking for pest protection, might be attracted, but not consumers desiring a tastier avocado. Few specialty crops outside papayas have been genetically engineered.

That's a far cry from the heady days of the early 90s when genetic modification was going to bring hordes of novel foods to the produce aisle. But the question remains: was it the timelines or the promise that was misestimated?

The current generation of GM crops are, in crop breeding terms, quite basic. As many pro-GM voices point out, the plants derived from traditional breeding techniques are more 'genetically modified' from their forebears than most GM crops. Bt corn, for example, produces a single protein, Cry1Ab, derived from the bacterium Bacillus thuringiensis, which makes it resistant to the corn borer.

As it turns out, finding one or two genes that generate consumer perceptions like 'the taste' is very hard. Calgene's Flavr-Savr tomato, introduced in the mid-nineties, was a misnomer. Rather than improve taste, it had an extra gene that interfered with polygalacturonase, an enzyme that softens cell walls during ripening. The genetic change made the Flavr-Savr more resistant to rotting.