Effect of benzyladenine, gibberellic acid, and Ethephon on growth and flower yield of chamomile (matricaria chamomilla L.) Plants

Abstract

An experiment at the University of Nairobi's Institute of Dryland Research Development and Utilization (IDRDU) in Kibwezi was conducted to study the effect of plant growth regulators benzyladenine, gibberellic acid, and ethephon on the growth and flower yield of chamomile plants. Plants were sprayed to run-off with various concentrations (0, 25, 50 and 75 mgllitre) of benzyladenine (BA) in two timings (4 and 6 weeks after transplanting - 4 and 6 WAT); gibberellic acid (GA) at rates of 0, 100, 200 and 300 mgllitre and ethephon at rates of 0, 50, 100 and 150 mgllitre at 6 WAT. Benzyladenine applications significantly (P = 0.05) increased the vegetative growth and flower yield of chamomile plants. BA treatment at 4 WAT had no effect on dry matter production by the plants. Application of BA at 6 WAT increased dry matter production by the shoots and roots and also caused more partitioning of the dry matter to the roots than to the shoots. Generally, response to BA treatment was higher with the lower concentration of 25 mgllitre. Ethephon significantly (P = 0.05) increased plant spread, dry matter production by the shoots and roots with greater partitioning of the dry matter to the roots, and also increased flower yield. Plant response to increasing ethephon application rates was linear. Spraying chamomile plants with GA reduced root growth and reduced flower yield at each harvest and consequently the total flower yield. The reduction on root growth and flower yield was linear and quadratic to increasing GA concentrations, respectively. This study shows that BA and ethephon could be incorporated in the management practices of chamomile to enhance plant growth and improve the yield of dry flowers.