He went to her house one evening and threatened her with blackmail. He wanted her to let him and his band of betes noirs, to be allowed to hire the judges for the upcoming show in Norwich, Norfolk. Norwich was the biggest show of the year and the finale of the season.
They would not hire real experienced judges, no, they would hire "ringers!"

They would brief the ringers as to what hen would take first place, second and third places. There would be no place for Martha!

These ringers would be well paid, so they did not talk.
The breeders and farmers would have a whip round to pay the ringers, if Beth agreed to the sordid scheme.
She really had no choice as George confronted her with what he knew. As she could not face the humiliation or the loss of her job, she agreed to George's request.
Whoever George hired, she would pretend it was her doing. If anyone found out, it would be her that took the fall.