The actual moment when a "daughter" species can (or will) no longer cross-breed with the population from which it sprang (the definition of speciation) is almost impossible to pinpoint, let alone to witness.

WSJ: Matt Ridley on the Possible Formation of a Species | Mind & Matter

To get the seeds to breed true the farmers have to cross-pollinate the plants, a laborious task that keeps a peak of a dozen workers busy for several months on just one acre.

FORBES: Magazine Article