Effect of Integrated Use of L-Tryptophan and Chemical Fertilizer on Growth and Yield Performances of Radish (Rhaphanus sativus L.)

Abstract

L-Tryptophan (L-TRP) is an essential amino acid that performs as a physiological precursor of auxins in higher plants. A pot experiment was conducted at the Agro Technology Park, Eastern University of Sri Lanka to find out the effect of integrated use of L-Tryptophan (L-TRP) and chemical fertilizer on growth and yield performance of Rhaphanus sativus L. There were six treatments with three replicates laid out in a Completely Randomized Design in a factorial arrangement. The treatment combinations were rates of fertilizer (recommended fertilizer rate by the Department of Agriculture and half of that recommendation), and concentration of L-TRP (0 M, 10-3 M, 10-4 M). Measurements were taken at 45 days after sowing of radish. There was a significant interaction (p<0.05) between the concentration of L-TRP and fertilizer rate on tested parameters of radish. All the tested parameter were significantly increased at 10-4 M of L-TRP over the control at recommended fertilizer rate while at half of recommended fertilizer rate, all the parameters were significantly high at 10-3 M of L-TRP over the control. It can be concluded that the application of L-TRP as a phytohormone precursor can be used to increase the growth and yield performance in radish at different fertilizer rate.