The hops are in a raised bed that gets lots of sun. This summer has been very rainy, and I wonder if this may have stunted the buds. Also the bed has just been covered with stew and sand for the winter and really no other maintenance. Do I need to thin the rhizomes?
You do not need to thin rhyozmes as far as I am aware, but I am not a gardener.
If I knew which country you were in and what variety you were growing then I could pull the local hop growers reports for you and they tend to have a area by area variety break down of yields.
Also, how many years have your hops been established?
I seem to recall in the UK 2018 the season was looking very good, but then rain and sun in the wrong order towards the end of the season reduced some farms yields significantly. And, wilt was a big issue for some varieties in 2018.