Hemp grown as a field crop rather than as a garden plant: variety choice against an end use, seeding rates and row spacing, fertility on a per-hectare basis, harvest windows, retting, and the machinery that has to be able to cut it.
The three end uses pull in different directions and cannot be fully combined. Fibre wants density, height and an early cut before the stem lignifies; grain wants the seed to mature and be harvestable; cannabidiol production wants spaced, branched plants and looks much more like horticulture. Deciding which one the field is for is the first agronomic decision, not a later one.
Two things matter more here than in any grow room. Compliance runs on the tetrahydrocannabinol threshold and on sampling and testing dates set by the regulator, and a crop that drifts over the limit is a legal problem rather than a quality problem. And in Thailand it is the flower that is the controlled herb under the Notification of the Ministry of Public Health Re: Controlled Herbs (Cannabis), B.E. 2568, which is what separates a fibre crop from a regulated one.
Where to start