Effect of Humic Acid, Treated Sewage Effluent and Radiation on Canola Growth and Oil Production

A greenhouse experiment was carried out to evaluate the role of Humic acid (HA) in improving canola (Brassica napus L.) growth when irrigated with treated sewage. We applied different concentrations of HA (0, 5, 10, 15, and 20 mg kg-1) during this study. Canola seeds were exposed to different doses of gamma rays (0, 100, 200, 300, 400 and 500 Gy). The response of canola plant to HA and irradiation was evaluated and found to rank as following; 15 > 20 > 10 > 5 > 0 mg.kg-1 and 300 > 200 > 100 > 400 > 0 > 500 Gy respectively. We also found that treatment with irradiation 200 Gy and 300 Gy enhanced the growth, micro-nutrients (Fe, Zn, Mn and Cu) uptake and the yield of oil.