GROWTH RESPONSE OF Sesbania emerus (Aubl) Urban ASSOCIATED WITH ARBUSCULAR ENDOMYCORRHIZAL FUNGI AND FERTILIZED WITH INORGANIC PHOSPHORUS

摘要

The plant growth response of Sesbania emerus (Aubl) Urban was assessed in a greenhouse in relation to inoculation of different arbuscular endomycorrhizal fungi (Glomus sp. Zac-19, Glomus aggregatum, Glomus etunicatum, Glomus intraradix and Glomus sp. Zac-6) in soil with different doses of inorganic phosphorus (50, 100, and 150 ppm P_2O_5). There was a completely randomized design with nine treatments and five replicates. The measured variables were: plant height, stem diameter, biomass dry weight of aerial parts, leaf area and the total percentage of endomycorrhizal colonization. The plants were harvested 170 days after the transplanting. It was found that all the treatments with endomycorrhiza and phosphorus improved plant growth significantly compared with the control. The symbiosis of Sesbania with Glomus varied significantly. The endomycorrhiza Glomus sp. Zac-19 had the greatest values in all the studied variables and was considered to be the most efficient endophyte. This suggested that there was a certain specific affinity between Sesbania emerus and the fungus Glomus sp. Zac-19. This could be seen by the high colonization rate (87.2%) observed with Glomus sp. Zac-19, which increased significantly the absorptive area of the plant root system. It was also determinate that Sesbania growth response had an important improvement with the inorganic P fertilization, but this effect was lower than mat of the mycorrhizas. We recommend inoculation with Glomus sp. Zac-19 as one of the cultural practices in the establishment of Sesbania emerus plantations.