The seed is used for culinary purposes (no alkaolids / drugs in the seed) but the rest of the capsule & some of the straw contains the alkaloids. Opium poppy isnt really a "true technical" term (the poppy produces opium when it is green but we harvest ours dry). I guess you could call them morphine poppies (although there are 2-3 other main types, namely Thebaine & Noscapine).
When done with combines it is cut low, when done with foragers it is cut higher (average crop is waist to shoulder height before harvest). With the forager, you are only taking the capsule (Seed head) + a minimum of straw (say 20 -30 cm / 8-12 inches).
The crop is taken to the processing factory, from the harvester (no cleaning or processing is done on farm),
Prices / returns arent as good now as they were a few years ago. Some crops returned (GROSS) $3500 - $4500 / Hectare (AUST $) this year but generally below this (due to frosts & the drought). Nett figures (less variable input costs) would be AUS $1000 - $2000 / Ha ($400 - $800 / acre).
The crop yields 1.5 - 2.5 tonnes / ha up to 4 tonnes / ha.