Abstract:To investigate the accuracy of SPAD chlorophyll meter in chlorophyll measurements and the effect of different fertilization treatments on SPAD value and chlorophyll content of Ficus hirta Vahl. (Wuzhimaotao) in ‘3414’ fertilizer experiment. SPAD value, chlorophyll a, chlorophyll b and total chlorophyll contents of different F. hirta leaf position were determined with both SPAD chlorophyll meter and alcohol-acetone extraction methods. Results showed that fertilization treatments showed no significant influence on SPAD values of three leaves chlorophyll a, chlorophyll b and total chlorophyll contents of the first-top-leaf, as well as chlorophyll a and total chlorophyll contents of the second-top-leaf, and chlorophyll b and total chlorophyll content of the third-top-leaf. However, fertilization treatments significantly changed the chlorophyll b and total chlorophyll contents of the second-top -leaf, and the chlorophyll a content of the third-top-leaf. The effects of nitrogen, phosphorus and potassium applications on the SPAD value and chlorophyll contents was in the following order: N fertilizer> P fertilizer> K fertilizer. SPAD value, chlorophyll a, chlorophyll b and total chlorophyll contents, increased, gradually, from the first-top-leaf to the third-top-leaf. There were negative correlations between SPAD value and chlorophyll a, chlorophyll b and total chlorophyll contents, respectively, for the first-top-leaf, and negative correlations between SPAD value and chlorophyll a content of the third-top-leaf. However, significant positive correlations between SPAD value and chlorophyll a, chlorophyll b and total chlorophyll contents, respectively, were identified for the second-top-leaf. Similarly, significant positive correlations between SPAD value and chlorophyll b content and total chlorophyll content were found in the third-top-leaf of F. hirta. All these results suggest that the SPAD value of the second-top-leaf is the best estimation for the chlorophyll contents of F. hirta in the “3414” fertilizer experiments. These findings provide a scientific basis for using chlorophyll meter correctly in the physiological experiment of F. hirta, and provide some theoretical guiding for the intercropping of F. hirta with mature rubber.