Piotr Starzec, 27, of Colworth Manor Farm, Chichester, was attempting to cross the busy road near Merston on September 15 last year when he pulled out into the motorcyclist’s path.
He admitted driving without due care and attention at Worthing Magistrates’ Court on Friday.
The court heard how Starzec had proceeded across the road after another motorist had flashed his headlights for him to cross.
However, he did not notice the motorcyclist in the other lane, and collided with him.
Mandy Allemand, prosecuting, said the victim was left requiring ‘extensive’ hospital treatment, has been unable to work and has not ridden since.
His family had to care for him and it culminated in the break up of his relationship.
“The thought of getting back on his bike makes him feel ill and he has been riding for 14 years,” she said.
Magistrates were also told the tractor’s windows were muddy, which may have shrouded Starzec’s view.
Defending, Tom Bourne-Arton said his client was an extremely hard-working farmer who was apologetic for his lapse in judgement.
He said: “The fact a driver flashed his headlights does not excuse it but it does explain why he did not take as much care as he ought to have taken.
“He is remorseful and sorry for what he has done.”
Magistrates handed him a £220 fine and five penalty points but, as Starzec currently holds a Polish driving licence, they were unable to add them to his licence.
The court clerk said the DVLA could be informed of the points, should the defendent apply for a UK driving licence.