An experiment was conducted to study the impact of different levels of nitrogen on growth and yield of radish in the Crop Farm, Faculty of Agriculture, and Eastern University, Sri Lanka during the period October to November 2017. Radish variety ‘Beeralu rabu’ was used in this study. This experiment was laid out in a Complete Randomized Design (CRD). There were six treatments with five replications. Urea was used as a source of nitrogen. The treatments were T1 - No fertilizer (Control), T2- 90 kg urea/ha, T3-120 kg urea/ha, T4-180 kg urea /ha (Recommended rate), T5-210 kg urea /ha, T6 - 240 kg urea /ha. Agronomic practices were carried out as per Department of Agriculture, Sri Lanka. Samplings were done at fortnight intervals.
The results showed the highest LAI at 240, 210 and 180kg N/ha. Maximum length and diameter were obtained at 240 and 210 kg N/ha. Highest dry weight and marketable tubers were recorded at 210 and 180 kg N/ha. Control was the lowest in LAI, length, diameter, dry weight per plant and the marketable yield of the tuber. The results suggest that marketable yield could be increased by five (5) and four and three quarter (4.75) folds the application of nitrogen at 210 and 180 kg N/ha, respectively and the further increase in nitrogen will decrease the marketable yield.
Keywords— Radish, Raphanus sativus L., Nitrogen, Marketable yield