What should I look for in an IBL?

[GrowFAQ]

First define your goals. Are you growing for yourself or for commercial production? Indoors or out? Mostly sativa or mostly indica? Keep only the plants that have the qualities you want, and mercilessly kill the rest.

Select plants that don’t fall over; if you have to prop them up with toothpicks, you might as well cull them. Keep the ones that are free from abnormalities and hermaphroditism. Hopefully you’ve got enough many seeds to be ruthless. Keep the ones that show better resistance to disease and pests. Even though the progeny performance is more important than the individual, there is a positive relationship between the overall vigour of an IBL and the yield of its hybrids. If they produce vigourous plants they are more likely to pass these traits on. Then employ a breeding strategy towards homozygosity, such as recurrent selection, selfing or cubing.

Following up on discussion of SWT3 inbreeding:

@HydroPower

Do I understand it correctly that it is very subjective term?

That IBL is stable only in those traits that breeder is looking for and only to the level that breeder assumes sufficiently “stable”.

@Baudelaire

Well, yes in practice, but not in theory. In theory a variety referred to as an IBL should be consistent in the expression of more or less all of the primary characteristics of value in a commercial crop - from stature to maturity period, disease resistance, leaf and fruit appearance, etc. “Peas in a pod” as Oldtimer says.

But you are right in that there are a lot of “IBLs” sold at seed shops that shouldn’t be labeled as such. Inbred lines need several generations of backcrossing by a skilled breeder to fix traits and cull out-of-character individuals. Most breeders don’t have the discipline to see a project through to IBL, and seed buyers don’t really reward the effort, because who cares if a strain is IBL or F1 if you are only going to plant 10 seeds and grow most strains once? If you like a strain you clone your best girl and you’re done.

IBLs are more important to breeders and the future’s large commercial ops, where Blue Dream and Bubba Kush will be planted like corn in Kansas, and harvested the same way. In those operations, having ten thousand seeds that grow exactly alike will be far more valuable.

-b420