AZOSPIRILLUM INOCULATION ON ZEA-MAYS

The performance of Zea mays treated with an Azospirillum broth was stu died through a random block design with ten replications. Treatments w ere: controls with 50, 75 and 100 kg N inoculated with the bacteria as cysts o vibrioids concentrated or diluted 1/10. All treatments were f ertilized with 30 and 60 kg of phosphorus and potassium, respectively and those inoculated with 50 kg N. Inoculation significantly increased dry matter yield (1.04-1.07 g/plant) in respect to the control with 5 0 kg N (0.90 g/plant) and the values were similar to the control ferti lized with 100 kg N (1.02 g/plant). Inoculation with a broth in a conc entrated static form had an N yield (16.28 mg/plant) higher than the c ontrol with 50kg N (13.01 mg/plant) and similar to the control with 75 kg N (15.27 mg/plant). The highest calcium contents (1.12-1.14%) and the lowest phosphorus contents (0.11-0.12%) were found with the inocul ant grown under agitation which significantly surpassed the control wi th 50 kg N (1.05 and 0.13%, respectively). Inoculation increased, exce pt in one treatment, magnesium percentage (0.54-0.55) which was simila r to the control with 100 kg N (0.51%). Maize yield shows the possibil ity of using both ways of preparing the inoculant. However, the prepar ation under agitation during 24 hr would be less costly. Nevertheless, the study of bacteria survival in plants with both preparations as we ll as its hormone production is recommended.