Influence of different shade levels on photosynthetically active radiation,
stomatal conductance and chlorophyll content in mint (Mentha spp.) types

Fifteen accessions of Japanese mint (Mentha arvensis L.), pepper mint (Mentha piperita L.) and spear mint (Mentha spicata L.) were evaluated under different shade conditions (Open, 25 and 50 per cent shade). Japanese mint recorded higher Photosynthetically Active Radiation (PAR) and pepper mint recorded increased Stomatal Conductance (Cs) under 25 per cent shade condition (162.57 µ mol m-2 s-1 and 2.57 µ mol m-2 s-1respectively). Under all the shades (open, 25 and 50 per cent), spear mint recorded higher Chlorophyll ‘a’ (0.601, 0.575 and 0.671 mg g-1 respectively) and chlorophyll ‘b’ (0.684, 0.764 and 0.790 mg g-1 respectively) contents. Accession S2A4 recorded an increased Stomatal Conductance (Cs) under open condition (10.96 µ mol m-2 s -1).