Regression models for leaf area estimation of Brazilian species of the genus Tillandsia L. (Bromeliaceae)


The objective of this study was to calculate adequate regression equations for estimation of leaf area of Tillandsia spp. native from Brazil. Leaf length along the central vein (C), maximum leaf width (L) and real leaf area were measured from at least 100 leaves for each species. Leaves were maintained intact at the plants. Relationships between the real leaf area and leaf dimensions C, L and CL (leaf length x leaf maximum width) were calculated with regression models. The linear regression model with intercept was the most adequate, and the recommended equations for each species, being LA= estimated leaf area, were: Tillandsia carminea, LA= 0,281188 + 0,562219 CL (R2= 0,7296);Tillandsia dura, LA= 0,891231 + 0,412457 CL (R2= 0,8432); Tillandsia gardneri, LA= 2,54412 + 0,445525 CL (R2= 0,8662); Tillandsia geminiflora, LA= 0,674484 + 0,444418 CL (R2= 0,8474); Tillandsia globosa, LA= 1,9494 + 0,3804 CL (R2= 0,8178); Tillandsia grazielae, LA= 0,518512 + 0,530259 CL (R2= 0,7608); Tillandsia kautskyi, LA= 0,59338 + 0,374353 CL (R2= 0,6931);Tillandsia reclinata, LA= 0,0379111 + 0,641623 CL (R2= 0,9169); Tillandsia stricta, LA= 0,3937 + 0,4277 C (R2= 0,8661), or LA= 1,21336 + 0,385727 CL (R2= 0,8607); Tillandsia tenuifolia, LA= 0,991226 + 0,402221 CL (R2= 0,7523).