Thresher is the skill that dwarves use when given the labor plant processing. "Processing plants" actually covers 4 different jobs done at a farmer's workshop.
- Turns pig tails, rope reed, flax plants, jute plants, hemp plants, cotton plants, ramie plants, and kenaf plants into the corresponding types of thread. These products produce seeds as well.
- Turns quarry bushes into quarry bush leaves and produces rock nuts. Five leaves and one rock nut are produced per quarry bush.
- Turns sweet pods into dwarven syrup and produces sweet pod seeds. Each sweet pod produces five units of syrup.
- Process plants (to vial):
- Turns valley herbs into Golden salve. Requires a glass vial. Currently there is no use for this extract other than as an export good.
 See also