摘要
This study was carried out at the farm of Horticulture Department Faculty of Agriculture and forestry, Duhok University, during the winter season of 2008 to investigate the effects of biofertilizer （Azotobacter） with different levels of Nitrogen fertilizer （urea 46%） （100, 200, 300 kg/hectare） and without Azotobacter （Nitrogen alone） on growth, yield quantity and quality of lettuce Ramadi cv. The experiment was designed according to RCBD with three replicates. The results showed that there was significant increase in studied characteristics （plant height （cm）, leaves number, length and of the stem （cm）, head fresh and dry weight （g）, head diameter and head yield （kg/m2）） except dry weight percentage of leaves and a significant decrease in NO3 in leaves by using Azotobacter with Urea especially at low levels.
