1. A system for measuring plant attributes during harvesting of a row crop comprising: a plant attribute sensor ( 103 , 108 , 110 ); a digital a priori plant location map ( 118 ); and an ECU ( 126 ) coupled to the plant attribute sensor ( 103 , 108 , 110 ) and configured to retrieve and use the a priori plant location map ( 118 ) to anticipate the presence of a plant to be harvested and to use the anticipated presence of a plant to improve accuracy of a plant measurement, wherein the plant measurement is provided by the plant attribute sensor ( 103 , 108 , 110 ).