Leaf area estimation of medium size plants using optical metrology

Abstract
One feature of most horticultural crop plants that is biologically relevant to their yield and productivity is total leaf area. . However, direct methods of estimation of the leaf area cause damage to the plants, whereas indirect methods based on light measurement demand accuracy in the set up of the measurement procedure, which can be difficult to achieve. The development of computer facilities and their accesscibility help the search for new indirect approaches which can be reliable for producers and researchers, with a good association with the real values produced by the direct methods. Coffee is one of the most important agricultural products in worldwide trade, and this demands some abilitiy to estimate the productivity of the crop. This work aims to build a model based on indirect measures to estimate the leaf area in youth coffee trees using image analysis. The experiments have been conducted using a sample of trees of the Topazio cultivar with a canopy height between 0.24 and 0.74 m. Two models were evaluated, one based on the height and width of the canopies, and one based on the area of the digital image of a tree. The results of the models have been compared with the real area of the leaves using the destructive approach with measurement of all the leaves areas using a digital scanner. Comparisons between the models and the real values indicated values of adjusted R2 about 0.95 with a model using the height and the width values, and again about 0.95 in the second model which used the area projection. The model using the height and the width values were validated using values presented in the literature to other cultivar and achieved R2 =0.82.
Year
2013
Category
Refereed journal
Output Tags
SG 2006-2011 P1 Plants - Miscellaneous