Influence of photoperiod and paclobutrazol on physiological characteristics of chrysanthemum (Chrysanthemum morifolium Ramat.) cv. Co. 1

Investigations were undertaken to study the influence of physiological characters on year round flower production in chrysanthemum (Chrysanthemum morifolium Ramat.) cv. Co.1 under polyhouse by providing artificial short and long days along with paclobutrazol application. Chlorophyll ‘a’, chlorophyll ‘b’ and total chlorophyll contents were found to be highest in 13 h shade treatment whereas anthocyanin content, net assimilation rate, crop growth rate, dry matter production and leaf area index were highest in 14 h shade treatment in February, April and June planted chrysanthemum crops. But all the physiological characteristics were observed with highest values in extending the day length by 2 h during August, October and December planting seasons. Paclobutrazol application at 50 ppm found to be the best concentration on all the characters during all the six seasons of planting.