Berries are fruit found in Dinousaur Land in Super Mario World. Yoshies could eat them for the value of one Coin, however; no points are given when a fruit is eaten. If Yoshi eats enough berries a cloud will appear and throw out coins.
If Yoshi eats a Green Berry (which are very rare) the games clock will gain more time, this makes sure you could reach the goal before the timer ran out.