Continual growth is important to his industry (6)
I believe the answer is:
farmer
'continual growth is important to his industry' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
This is all the clue.
Can you help me to learn more?
(Other definitions for farmer that I've seen before include "Tender of crops/stock" , "the tax-collector?" , "One who works the land" , "One who cultivates land" , "Crop grower or livestock keeper" .)