Hijuelo
A clonal basal offshoot of an agave, literally "little child"; the unit of clonal propagation in tequila and in part of the mezcal industry.
A hijuelo (Spanish diminutive of hijo, "child," meaning roughly "little offshoot") is a genetically identical clone that an agave produces at the base of its rosette, sprouting from a horizontal underground stem called a rhizome. The parent plant uses hijuelos as a hedge: even if the central rosette fails to flower successfully, the clones live on. In A. tequilana a healthy mother produces 4 to 8 hijuelos per year over its lifespan.
The hijuelo is the backbone of commercial tequila agriculture and a large part of cultivated mezcal. A field of A. tequilana is essentially a single genome replicated across a million plants: hijuelos are dug up at 1 to 2 years old, separated from the mother, and replanted in rows. The resulting monoculture has extremely low heterozygosity. The same is partly true of cultivated espadín (A. angustifolia), though traditional mezcal producers more often allow seed-grown plants alongside hijuelos.
Hijuelos are a producer's working capital. They are also the genetic bottleneck that makes the agave industry vulnerable to disease, and the practice that the Bat Friendly program targets when it asks producers to allow at least 5 percent of mature plants to flower naturally (restoring seed-based genetic diversity to the field). See the botany chapter Part 5 for the genetic-diversity argument and the distillation chapter Part 1 for the field-rotation context.
Sources
- Vega-Frutis, R. et al. Population genetics of Agave tequilana: low diversity in cultivated stands. Plant Systematics and Evolution (2010).
- Bat Friendly Tequila and Mezcal program.
- Consejo Regulador del Tequila. Production process.