the meaning of 'take on'

[kjc0123]

What is the meaning of "taking on" in the following sentences?

The National Labor Relations Act of 1935 had excluded agricultural workers from its guarantee of the right of labor to organize and bargain collectively. But Cesar Chavez, founder of the overwhelmingly Hispanic United Farm Workers, demonstrated the efficacy of direct action in seeking recognition for his union. Taking on the grape growers of California, Chavez called for a nationwide consumer boycott that finally provided exploited migrant workers with union representation. Similar boycotts of lettuce and other products were also successful. Though farm interests continued to try to obstruct Chavez's organization, the legal foundation had been laid for representation to secure higher wages and improved working conditions.

[mrs.pudding]

He means 'confronting' or being willing to argue with the grape growers in order to achieve the result he desires.

[Peter Pedant]

Hi kay-jay have you tried any Dickens or Austen yet?

[docvann_91w]

He took it upon himself to take them to court most likely.  It means that he went against them and "took on" the challenge of trying to prevent his injustice.