Comparison of two methods for estimating leaf area index on common bean

Measurement of leaf area index (LAI) is important in studies of plant growth. Based on this concept, the analysis of crop growth has moved from classical growth analysis to mechanistic models, via functional growth analysis. Leaf area index is a major variable in mechanistic crop growth models and in models that attempt to simulate loss caused by pathogens. A field experiment was carried out from May through August 1998, using common bean (Phaseolus vulgaris L. cv. Carioca), in a randomized complete block design with two methods of LAI evaluation and three replications. The objective of this study was to compare the applicability of the LAI-2000 Plant Canopy Analyzer with the central leaflet width method used to estimate LAI in common bean. The high correlation (r(2) = 0.97) observed between the two methods used to estimate LAI shows agreement between them. The results of this study indicated that the LAI-2000 can be used to estimate the LAI of common bean.