Your son might start to become interested in eating food more by himself at this age and I suggest you could try to cook, or steam, fresh vegetables for him and cut in to small pieces and serve him. Frozen peas for example are great to start with (those you just have to heat up for a few minutes, let cool a little, and serve). Small pieces of cooked carrots are also good starters. Corn and sweet potato as well.
This might take his mind off the sweet fruits for a little bit. You can also try to mix the vegetables with the cereal to make him eat it that way.
I have two sons, my youngest is 10 months old, and they never really liked the baby jar food, especially not the green veggies.
I can also tell you from experience that babies like different foods and eats different kinds of foods at different times, some weeks they like it sweet and some they don't (they usually will always eat fruit however). Try mixing things up a little and see if he wants to eat his veggies again in a few days.
mother of two boys, 4 1/2 years and 10 months old