02100naa a2200277 a 450000100080000000500110000800800410001902400390006010000200009924501020011926000090022152012430023065000120147365000210148565300250150665300200153165300230155165300300157465300230160465300120162770000230163970000230166270000260168570000230171177300880173420149662016-03-29       2015    bl uuuu     u00u1 u    #d7 a10.1590/1983-40632015v45306172DOI1 aPINHEIRO, K. M.  aIndirect methods for determining the area index of forage cactus cladodes.h[electronic resource]  c2015  aMethods for determining leaf area index have been applied to various agricultural crops. However, their uses are limited to broadleaf plants, with no record for forage cactus, whose radiation interception is performed by the cladode. This study aimed to evaluate the use of different indirect methods to estimate the area index of forage cactus cladode. Cladodes from clones of Nopalea cochenillifera Salm Dyck, Nopalea cochenillifera Salm Dyck and Opuntia stricta (Haw) Haw were used, being sampled sixty plants per clone, distributed in five sub-areas with 12 plants. Light interception methods with different measurement techniques were evaluated, as well as the planimetric, leaf discs and odeling methods. The estimate of area index of the forage cactus cladode by the modeling method was considered the most accurate one, for presenting precision coefficient values and accuracy above 0.90, as well as a performance varying from very good to excellent. However, its applicability depends on the use of estimated parameters or adjusted value equations. The methods of light interception and its derivations, leaf discs of medium cladodes and planimetry of medium cladodes are not recommended, due to their low precision and accuracy.  aOpuntia  aPalma forrageira  aAnalisador de dossel  aCanopy analyzer  aDestructive method  aIndice de área cladódio  aMétodo destrutivo  aNopalea1 aSILVA, T. G. F. da1 aDINIZ, W. J. da S.1 aCARVALHO, H. F. de S.1 aMOURA, M. S. B. de  tPesquisa Agropecuária Tropical, Goiâniagv. 45, n. 2, p. 163-171, abr./jun. 2015.