What does agriculture have to do with world hunger?
Agriculture basically refers to farming. So this is where all the crops that feed the world come from.
More agriculture should theoretically stop world hunger as everyone would have enough food (although this wouldn’t actually be the case as the Western world has 80%of the world’s total food resources).
So, in answer to your question, without agriculture, there would be much more world hunger than there already is.
If places that suffer from hunger were to teach the people agriculture, they could start subsistence farming and that would help world hunger end, although of course we can’t tell if it will stop it completely.