Strikebreakers are commonly given derogatory terms like scab and blackleg.
From the en.wikipedia.org
Blackleg disease can devastate crops and in 2003 caused 90% yield losses in some regions of Australia.
From the sciencedaily.com
Blackleg train drivers were brought over from England after drivers refused to carry British troops.
From the en.wikipedia.org
The disease affecting your crop, I think, is potato blackleg, a common bacterial disease which causes black rotting at the stem base.
From the eadt.co.uk
A fungus which causes blackleg, a devastating disease afflicting some members of the cabbage family, makes a previously unknown type of toxin, say researchers in Canada.
From the newscientist.com
More examples
Scab: someone who works (or provides workers) during a strike
Fink: take the place of work of someone on strike
Blackleg, black quarter, quarter evil, quarter ill (Gangraena emphysematosa) is an infectious bacterial disease of sheep and cattle, caused by Clostridium chauvoei bacteria. It is found all over the world. ...
(Blacklegged) A strikebreaker (sometimes derogatorily called a scab) is a person who works despite an ongoing strike. ...
Fatal cattle disease caused by soil-borne bacteria; A person who takes the place of striking workers. A scab; A person who cheats in a game, a cheater; Relating to a scab worker
(BLACKLEGS) A gambler or sharper on the turf or in the cockpit: so called, perhaps, from their appearing generally in boots.
A highly fatal disease of young cattle caused by one type of Clostridium bacteria. See Clostridial disease.
(derog.) a person who fails or declines to take part in an industrial action. 2. Leptosphaeria maculans, a microbial fungus that infects canola and cattle; the disease is almost always fatal to cattle.
A nineteenth century term for a card player of ill repute.