Effect of phosphate solubilizing bacteria on the growth of Agave angustifolia Haw. (maguey espadín)

Experiments were conducted to evaluate the potential effects of phosphate solubilizing bacteria (PSB) on the growth of maguey espadín (Agave angustifolia Haw.). A total of nine strains of PSB, previously isolated in the maguey rhizosphere and identified as PSBVa, PSBVb, PSBVf, PSBHa, PSBHc, PSBHd, PSBMg, PSBMh and PSBMi were tested on maguey plants grown in phosphorus-deficient sterilized and unsterilized soils of three sites where maguey is grown (valley, hill and mountain) under greenhouse conditions. Aerial dry weight and the total weight of maguey plants inoculated with PSBMh in unsterile mountain soil increased by 12.14% and 10.99% respectively, compared with the uninoculated control. Total root dry weight increased by 17.85% with PSBMh in sterile mountain soils and by 11.64% with PSBMg in unsterile mountain soils, with respect to the uninoculated sterile and unsterile control respectively. Plant stem diameter increased by 13.61% with PSBVb in unsterile valley soil, compared to the uninoculated control. Root length was 56.84% higher with PSBMi in unsterile mountain soils than the uninoculated control. Plant leaf number increased by 35% with PSBHd in unsterile hill soil, with respect to the uninoculated control. In all treatments, the available phosphorus at harvest was higher than pre-planting levels. This study suggests that isolated PSBMh, PSBMg and PSBMi are the most efficient biofertilizers for maguey espadín cultivation.