Growth and production potential of quinoa (Chenopodium quinoa Willd.) under varying doses of soil applied urea

Quinoa (Chenopodium quinoa Willd.), a lesser-known food and feed crop is gaining acceptance in Pakistan. It is being cultivated to develop its production technology under local conditions. A balanced fertilization ensures the maximum economic return. Therefore, a field experiment was proposed to optimize the dose of nitrogenous fertilizer on the phenology and production potential of quinoa, at Agronomic Research Area, University of Agriculture, Faisalabad during November 2012. The experiment was performed using three promising genotypes HMB-3, HMB-4 and HMB-5 with four nitrogen levels (80, 100, 120, 140 kg per ha) in two split doses (one basal dose and one with first irrigation). Experiment was laid out in randomized complete block design (RCBD) with split plot arrangement in three replications and a net plot size of 1.8 m x 7.0 m. Statistical analysis of data revealed that all the growth and yield related traits such as leaf area, leaf area index, leaf area duration, crop growth rate. net assimilation rate, total dry matter, plant height, stem diameter, number of leaves per plant, number of branches per plant, number of panicles per plant, main panicle length, main panicle weight, sub panicles weight and thousand grain weight were recorded the highest in respect of genotype HMB-4 and the minimum for genotype HMB-5 among three genotypes under study. Similarly, an increase in growth and yield components was observed with increasing nitrogen levels up to maximum i.e. 140 kg N per ha except main panicle weight, sub panicles weight and thousand grain weight which were the maximum at 100 kg N per ha. The interactive effect of N was non-significant with all traits except biological yield, economic yield and harvest index and were maximum for genotype HMB-4 at nitrogen level of 100 kg per ha. Nitrogen application also increased leaf chlorophyll content (40.124 mg g-1 fresh wt.) and total phenolics (9.2976 mg g-1 fresh wt.) when soil was fertilized with 140 kg N per ha and 80 kg N per ha, respectively. Soil invigoration with 100 kg N per ha was evaluated as the best to attain maximum economic yield of quinoa.