Seasonal variation in radiation distribution and radiation use efficiency in some flowering plants

The present study has been conducted to evaluate radiation environment within Chrysanthemum, Inca and Bougainvillea and to quantify the PAR use efficiency of the flowering plants. Three ornamental flowering plants; Chrysanthemum, Inca and Bougainvillea were selected from Bhairab Ganguly College garden (Latitude 22˚66'01" N & Longitude 88˚38'08" E) and incident PAR, reflected PAR and transmitted PAR were measured on 15 different dates. Also three leaves were taken from each plant on 15 different dates for LAI computation. The observations were recorded from 7th December, 2018 to 30th March, 2019. In totality 15 observations were recorded. The incident PAR over the vegetations were high on different dates but bottom incident PAR was very low. Transmitted PAR shows that the transmission was always high on Bougainvillea from December 2018 to March 2019. Interception PAR among the three vegetation were quite different i.e., from 2 nd week of December high amount of interception was recorded on Inca otherwise Chrysanthemum had high interception rate. However, overall mean interception was high on Chrysanthemum. Reflectance also varied on different months. Increasing biomass accumulation with increase of solar radiation on different dates was recorded. Leaf area index (LAI) widely varied in different months. Maximum value was recorded on Chrysanthemum. Among the three vegetation, LAI growth was high in the month of December in respect of low temperature. Maximum k value of Inca was observed on 29th December whereas in Bougainvillea maximum k value was recorded in the month of February.