Fig. 4 Correlation between results from water soluble extracts from leaves of rice plants of four rice cultivars on lettuce and ducksalad root growth. , PI312777; , Rexmont; •, Taichung Native 1 (TN1); , Taichung 65. Each point shows the average lettuce and ducksalad root length of three replications when applying the same extract. ***, Significant at the 0.1% level