USE OF PHOSPHATE-SOLUBILIZING BACTERIA IN THE SUGARCANE ROOTAGE PROCESS

Martínez G. Alexandra Martínez, S. María M

Facultad de Ciencias. Carrera de Bacteriología. Pontificia Universidad Javeriana. Cra. 7 No. 43-82. De. Félix Restrepo, Of. 111 - Santa Fe de Bogotá

100 samples of rizosphere taken from 16 cultures located in Tolima, Cundinamarca and Casanare departments were assessed to isolated solubilizing bacteria (PSB) populations. The PSB constituted the 20% of the total isolated population. 2 microorganisms isolated Xanthomonas maltophilia and Enterobacter cloacae were selected because of their ability to form clear zones around in Pikovskaya medium with Ca₃(PO₄)_2. In a greenhouse assay, buds of sugar cane variety Venezuela 51-71, were planted and fertilized with Fosforita Huila, in the rooting media called Grower´s Oasis, then a inoculation with the 2 microorganisms seleted, was performed. In the treatments there were significant differences in phosphate uptake at 90 days in relation to the control. However, there were significant differences in plants growth, were stem length with the phosphate treatment and the mixture of the 2 bacterias was 32cm compared with 17cm of the positive control. Similary stem length with the phosphate treatment and Enterobacter cloacae was 9cm compared with 5cm of the positive control.

In relation to the root growth in increased its dry weight 2.57 times more than the positive control and root weight was increased 0,73 times being similar with the KNO₃ control.