Leaf area is an important index in plant growth study and in prediction of the product of crop. Various methods as square
grid counting and gravimetric and pixel counting using image processing are mostly used for leaf area measurements. On
the other hand, when dealing with a large number of leaves,these approaches turn out to be laborious and time consuming. A solar cell based method for leaf area measurement was developed and implemented. In this system, the shadowing effect by the plant leaf on the solar cell was used. The system has two 7 ∗ 10cm2 and 5 ∗ 7cm2 amorphous silicon solar modules which were composed of 6 series connected cells, an 11WPL lamp, a stainless steel parabolic reflector for reflecting the light from the light source to the solar module in parallel, an opal glass used for diffusing the parallel reflected light, and a case for housing these components.Different geometric shaped areas were used to simulate the leaves having various shapes. The current and voltage values were measured due to shadowing effect of these areas to be evaluated. The resulting voltage and current measurements were then fed to an ARM Cortex M3 core 32-bit LM3S1968 microcontroller via a voltage and current measuring unit.The calculated leaf areas from the obtained area current relations were shown on an OLED graphics display. The whole system is easy to use and user-friendly.The achieved results are compared with the measured areas by grid counting method. Different species of leaves are tested by the leaf area meter. Experimental results show that this developed method contributes to a result that is reasonable to be used as a leaf area meter. Accuracy of this method is found to be about ±99% for regular shaped leaves where accuracy is ±95%for irregularly shaped leaves. The leaf area measurements are confirmed by comparing the results with measurements of grid counting method.