Effect of Different Shade Levels on Growth, Physiology and Biochemical Characteristics of Small Cardamom (Elettaria cardamomum Maton)

Elettaria cardamomum was grown under shade levels (75% shade, 50% shade and open irradiance) to evaluate its photosynthetic characteristics, physiology and biochemical characters. The highest net photosynthetic rates and stomatal conductance were observed under 75% shade, followed in descending order by 50% and open condition. The highest quantum yield of photosystem II was observed under 50% shade. As shade level increased, Chl a,Chl b and total Chl contents also increased significantly. The total number of opened stomata generally displayed the best activity in leaves subjected to 75% shade. The highest total phenol and epicuticular wax contents were observed in open irradiance treatment and highest proline level was observed in plants subjected to the 50% shade treatment. The results indicate that increased plant height, chlorophyll and proline contents and higher quantum yield of Photosystem II and stomatal activity may play an essential role in shade adapting mechanism in small cardamom.