THE AGRICULTURAL APPLICATION FLIGHT HAD JUST DEPARTED AND WAS IN CRUISE FLIGHT ABOUT 100 FEET AGL WHEN THE ENGINE FAILED SUDDENLY. THE PILOT EXECUTED A FORCED LANDING TO A FIELD AND STRUCK A TREE ON LANDING ROLL. THE AIRPLANE BURST INTO FLAMES, THE PILOT ESCAPED AND THE AIRPLANE AND ENGINE WERE CONSUMED BY FLAMES. THE REASON FOR THE LOSS OF ENGINE POWER WAS NOT DETERMINED.