Effect of environmental factors on nitrifying bacteria isolated from the rhizosphere of Setaria italica (L.) Beauv

Nitrification is a biological process in which nitrifying bacteria oxidise ammonia to nitrate. The process is sensitive to environmental factors such as temperature, dissolved oxygen concentration, pH, and available substrate. In the present study, the effects of pH, temperature and neem oil on Nitrosomonas and Nitrobacter isolated from the rhizosphere of foxtail millet, Setaria italica, were examined. The optimum temperature for the growth of both nitrifying bacteria is 30°C. Nitrobacter is less tolerant to low temperature than Nitrosomonas but the optimum pH for both bacteria is 8.0. Neem oil, when applied at 10 ppm, showed maximum inhibitory effect on growth of both bacteria

Evaluation of effect of inoculation of Azospirillum on the yield of Setaria italica (L.)

Inoculation of foxtail millet (variety Lepakshi) with three strains of Azospirillum lipoferum either alone or in combination with nitrogen fertilizer (40 kg N ha-1) increased the plant height, dry weight of shoot and root, and total N content of shoot, root and grain. The grain yield of the inoculated plants was significantly higher compared to the control plants. Both the panicle and the seed weight increased due to inoculation. Among the inocula of A. lipoferum tested, Inoculum-2 (In-2) was found superior to the other two inocula. Further, seasonal (Kharif and Rabi) variations in growth and yield of the plants werealso observed