Diurnal changes in photosynthesis rate at different levels of canopy in Musa paradasiaca (Linn.) cv. nendran

An experiment was conducted on Musa paradasiaca cv. Nedran to investigate the photosynthesis rate during different times of the day at different stages (30 days before anthesis, during anthesis, 30 days after anthesis and 60 days after anthesis). The leaf number 1,2,3,4 and 5 from top showed maximum photosynthesis rate in all the reproductive stages. The maximum photosynthesis rate at 30 days before anthesis, during anthesis and 30 days after anthesis was above 25 μmol CO₂ m⁻² sec⁻¹; while 60 days after anthesis the maximum photosynthesis rate was below 18 μmol CO₂ m⁻² sec⁻¹. At all reproductive stages the photosynthesis rate was high during the forenoon. The decrease in photosynthesis towards afternoon in photosynthetically active leaf may be due to accumulation of photosynthates causing a feedback inhibition. In Nendran, the presence of green foliage which looks productive is always having a positive carbon gain.