The ability of a potato (Solanum tuberosum L.) plant to intercept solar radiation is closely related to tuber yield. Leaf Area Index and ground cover measurements are frequently used to estimate light interception. Within this experiment LAI and ground cover were highly correlated even under different management practices with correlation coefficients ranging from 0.52 to 0.92. When correlating LAI and ground cover the slope of the linear correlation varied with management, suggesting that LAI increased more rapidly than ground cover under some conditions. The differences between slopes may provide an estimate of canopy light interception efficiency. Leaf area duration (LAD) explained 74 and 79% of the difference in total tuber yield while ground cover duration (GCD) explained 74 to 87% of the variation in 1997 and 1998, respectively.