RESPONSE OF THE MILLET PLANT PENNISETUM AMERICANUM L. TO INOCULATION WITH AZOSPIRILLUM BRASILENSE

The study aims to isolate and characterize Azospirillum bacteria for the purpose of studying its effect alone or in combination with nitrogen fertilization on the growth of Pennisetum americanum L. millet by growing it in a greenhouse. (4) isolates of Azospirillum bacteria, which were isolated from the roots of millet plant, were collected from Al-Rifai city / Dhi Qar. All isolates were of A. brasilense, and isolate A1 of A. brasilense was selected for use in the greenhouse experiment, on the basis of its high activity and efficiency in secreting IAA compared to the rest of the isolates. The result of the study showed that inoculation with bio-fertilizer (Azospirillum) gave a significant increase in the dry matter weights of the vegetative and root groups, plant length, root length and number of lateral roots compared to the control treatment (without bio-chemical fertilization), and this indicates that the bacterial bio-fertilizer has supplied millet plants with their needs. Dietary component nitrogen during the growth phase. The results also indicate the ability of Azospirillum isolates to produce IAA, and the highest produced amount was 21.7 mg L-1, which was recorded by isolate A1, which gave a significant superiority for the dry weight of the root group, root length and number of lateral roots compared to the control treatment (N%0) and the treatment of nitrogen fertilization not inoculated with fertilizers Viability (N%100), this indicates that the bacterial biofertilizer prepared millet plants with IAA, which in turn stimulated the root group to grow in addition to fixing atmospheric nitrogen.