Monitoring Optical Tool to Determine the Chlorophyll Concentration in Ornamental Plants

Abstract

The accurate estimation of leaf photosynthetic pigments concentration is crucial to check the plant´s health. Traditional methods of measuring photosynthetic pigments involve complex procedures of solvent extraction followed by spectrophotometric determinations. Portable plant instruments such as Soil Plant Analysis Development (SPAD) meters can facilitate this task for the speed and simplicity of the measures. The relationship between chlorophyll index obtained by SPAD-502 and pigment concentration in several ornamental species can help in the management of ornamental plant production. Two trials have been carried out in two different growing seasons (spring and summer) and facilities (greenhouse and open air), involving 30 ornamental species. There was a high linear relationship between concentrations of Chla and Chlb, as well as between Chlt and Ct in different species studied under greenhouse and open field conditions. The ratio between Chla and Chlb was higher at open field conditions and similar between Chlt and Ct. There was also a good relationship between Chlorophyll index and Chlt under both growing conditions, as well as between Chlorophyll index and Ct under greenhouse conditions. However, linear relationships with different slopes were observed for groups of species at open field conditions.