Leaf area estimation of medium size plants using optical metrology

Abstract

The total leaf area (TLA) estimation is an important feature of the crops and their assessment a challenge, since the direct methods of obtaining it are destructive and time consuming. Non-destructive methods have been explored to obtain the TLA by indirect approaches, in turn creating other features, as the leaf area index. The development of non-destructive technology to access the TLA of a plant has been the subject of much research, and the optical metrology is an promising approach. In this work, some indirect methods associated with optical approaches were evaluated as an alternative to obtain the TLA of the coffee plant. Commercial equipment were used, such as a camera with a fish eye lens and lux meters, associated to the sizes of the canopies were tested and compared to another non-destructive method and with methods proposed in the literature. The association between production and the TLA estimated was also evaluated. The results showed that the commercial equipment, generally used in forestry, was not the best approach in coffee plants, and that the methods related to the size and lux values of the plants were the best alternatives to estimate the TLA of the coffee plant.