For true-breeding pure Indicas, and particularly for potent Indicas, check out Afgaan 90, X18, and Deep Chunk.
Afgaan 90 is a selectively bred Afghan recently resurrected from 1990 Amsterdam seed stock.
X18 and Deep Chunk are ’80s Pakistani and ’70s Afghan strains originally inbred by Tom Hill and since maintained in Spain.
Balkhi, a recent landrace accession from northern Afghanistan, has readily shown unusually potent plants, some over 20% THC.
In landraces, to find +10% THC individuals in first-generation populations direct from regions such as Afghanistan usually requires searching for exceptionally potent Type 1 plants. These have been idenitifed in unworked strains from the Middle East, Himalaya, and elsewhere.
