Jack Walton, age 11, of Tulsa, Okla., for his question:

WHY DOES THE TOMATO CHANGE COLOR?

Rich in vitamins A and C, there is probably no other garden product that has as many uses as the tomato. It is the leading crop among those canned in the United States.

The tomato fruit is green in color at first. When it ripens, it turns to either yellow or red. The change in color is because of the fruit's ripening.

Slicing or table tomatoes are harvested while the fruit is still somewhat immature. Fruits to be shipped long distances are picked just as they begin to turn pink. They will keep for some time and will ripen and turn red as they get closer to market.

Cannery tomatoes and those used for making tomato soup must not be picked until the fruit is fully ripened.